Discover opportunities to engage students in science, technology, engineering and math (STEM) with lessons and resources inspired by the latest happenings at NASA.

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Illustration of spacecraft on a light blue background that reads "NASA Pi Day Challenge"

Cartoonish illustration of spacecraft on a dark purple background with various pi formulas

Update: March 15, 2021 – The answers are here! Visit the NASA Pi Day Challenge slideshow to view the illustrated answer keys (also available as a text-only doc) with each problem.


Learn about pi and the history of Pi Day before exploring some of the ways the number is used at NASA. Then, try the math for yourself in our Pi Day Challenge.

Infographic of all of the Pi in the Sky 7 graphics and problems

Visit the Pi in the Sky 8 lesson page to explore classroom resources and downloads for the 2021 NASA Pi Day Challenge. Image credit: NASA/JPL-Caltech | + Expand image

In this black and white animated image, a circular device stretched out from a robotic arm descends quickly toward a rocky surface, touches it, and then ascends as debris flies all around.

Captured on Oct. 20, 2020, during the OSIRIS-REx mission’s Touch-And-Go (TAG) sample collection event, this series of images shows the SamCam imager’s field of view as the NASA spacecraft approached and touched asteroid Bennu’s surface. Image credit: NASA/Goddard/University of Arizona | › Full image and caption

The Ingenuity Mars helicopter has a small box-like body topped by two sets of oblong blades. Four stick-like legs extend from the body of the helicopter.

In this illustration, NASA's Ingenuity Mars Helicopter stands on the Red Planet's surface as NASA's Perseverance rover (partially visible on the left) rolls away. Image credit: NASA/JPL-Caltech | › Full image and caption

A giant dish with a honeycomb-patterned device at its center is shown in a desert landscape.

This artist's concept shows what Deep Space Station-23, a new antenna dish capable of supporting both radio wave and laser communications, will look like when completed at the Deep Space Network's Goldstone, California, complex. Image credit: NASA/JPL-Caltech | + Expand image

A swirling fabric of glowing neon green, orange, and pink extends above Earth's limb. A partial silhouette of the ISS frames the right corner of the image.

Expedition 52 Flight Engineer Jack Fischer of NASA shared photos and time-lapse video of a glowing green aurora seen from his vantage point 250 miles up, aboard the International Space Station. This aurora photo was taken on June 26, 2017. Image credit: NASA | › Full image and caption

In the News

As March 14 approaches, it’s time to get ready to celebrate Pi Day! It’s the annual holiday that pays tribute to the mathematical constant pi – the number that results from dividing any circle's circumference by its diameter.

Pi Day comes around only once a year, giving us a reason to chow down on our favorite sweet and savory pies while we appreciate the mathematical marvel that helps NASA explore Earth, the solar system, and beyond. There’s no better way to observe this day than by getting students exploring space right along with NASA by doing the math in our Pi Day Challenge. Keep reading to find out how students – and you – can put their math mettle to the test and solve real problems faced by NASA scientists and engineers as they explore the cosmos!

How It Works

Dividing any circle’s circumference by its diameter gives us pi, which is often rounded to 3.14. However, pi is an irrational number, meaning its decimal representation goes on forever and never repeats. Pi has been calculated to 50 trillion digits, but NASA uses far fewer for space exploration.

Some people may think that a circle has no points. In fact, a circle does have points, and knowing what pi is and how to use it is far from pointless. Pi is used for calculating the area and circumference of circular objects and the volume of shapes like spheres and cylinders. So it's useful for everyone from farmers storing crops in silos to manufacturers of water storage tanks to people who want to find the best value when ordering a pizza. At NASA, we use pi to find the best place to touch down on Mars, study the health of Earth's coral reefs, measure the size of a ring of planetary debris light years away, and lots more.

In the United States, one format to write March 14 is 3.14, which is why we celebrate on that date. In 2009, the U.S. House of Representatives passed a resolution officially designating March 14 as Pi Day and encouraging teachers and students to celebrate the day with activities that teach students about pi. And you're in luck, because that's precisely what the NASA Pi Day Challenge is all about.

The Science Behind the 2021 NASA Pi Day Challenge

This year, the NASA Pi Day Challenge offers up four brain-ticklers that will require students to use pi to collect samples from an asteroid, fly a helicopter on Mars for the first time, find efficient ways to talk with distant spacecraft, and study the forces behind Earth's beautiful auroras. Learn more about the science and engineering behind the problems below or click the link below to jump right into the challenge. Be sure to check back on March 15 for the answers to this year’s challenge.

› Take the NASA Pi Day Challenge

› Educators, get the lesson here!

Sample Science

NASA’s OSIRIS-REx mission has flown to an asteroid and collected a sample of surface material to bring back to Earth. (It will arrive back at Earth in 2023.) The mission is designed to help scientists understand how planets form and add to what we know about near-Earth asteroids, like the one visited by OSIRIS-REx, asteroid Bennu. Launched in 2016, OSIRIS-REx began orbiting Bennu in 2018 and successfully performed its maneuver to retrieve a sample on October 20, 2020. In the Sample Science problem, students use pi to determine how much of the spacecraft's sample-collection device needs to make contact with the surface of Bennu to meet mission requirements for success.

Whirling Wonder

Joining the Perseverance rover on Mars is the first helicopter designed to fly on another planet. Named Ingenuity, the helicopter is a technology demonstration, meaning it's a test to see if a similar device could be used for a future Mars mission. To achieve the first powered flight on another planet, Ingenuity must spin its blades at a rapid rate to generate lift in Mars’ thin atmosphere. In Twirly Whirly, students use pi to compare the spin rate of Ingenuity’s blades to those of a typical helicopter on Earth.

Signal Solution

NASA uses radio signals to communicate with spacecraft across the solar system and in interstellar space. As more and more data flows between Earth and these distant spacecraft, NASA needs new technologies to improve how quickly data can be received. One such technology in development is Deep Space Optical Communications, which will use near-infrared light instead of radio waves to transmit data. Near-infrared light, with its higher frequency than radio waves, allows for more data to be transmitted per second. In Signal Solution, students can compare the efficiency of optical communication with radio communication, using pi to crunch the numbers.

Force Field

Earth’s magnetic field extends from within the planet to space, and it serves as a protective shield, blocking charged particles from the Sun. Known as the solar wind, these charged particles of helium and hydrogen race from the Sun at hundreds of miles per second. When they reach Earth, they would bombard our planet and orbiting satellites were it not for the magnetic field. Instead, they are deflected, though some particles become trapped by the field and are directed toward the poles, where they interact with the atmosphere, creating auroras. Knowing how Earth’s magnetic field shifts and how particles interact with the field can help keep satellites in safe orbits. In Force Field, students use pi to calculate how much force a hydrogen atom would experience at different points along Earth’s magnetic field.

Teach It

Pi Day is a fun and engaging way to get students thinking like NASA scientists and engineers. By solving the NASA Pi Day Challenge problems below, reading about other ways NASA uses pi, and doing the related activities, students can see first hand how math is an important part of STEM.

Pi Day Resources

Plus, join the conversation using the hashtag #NASAPiDayChallenge on Facebook, Twitter, and Instagram.

Related Lessons for Educators

Related Activities for Students

TAGS: Pi, Pi Day, NASA Pi Day Challenge, Math, Mars, Perseverance, Ingenuity, Mars Helicopter, OSIRIS-REx, Bennu, Asteroid, Auroras, Earth, Magnetic Field, DSOC, Light Waves, DSN, Deep Space Network, Space Communications

  • Lyle Tavernier
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As we count down to landing on February 18, learn how, why, and what Perseverance will explore on Mars, plus find out about an exciting opportunity for you and your students to join in the adventure!


In the News

On Feb. 18, NASA's Perseverance Mars rover is scheduled to touch down on the Red Planet after a seven-month flight from Earth. Only the fifth rover to land on the planet, Perseverance represents a giant leap forward in our scientific and technological capabilities for exploring Mars and the possibility that life may have once existed on the Red Planet.

Here, you will:

Why It's Important

You might be wondering, "Isn't there already a rover on Mars?” The answer is yes! The Curiosity rover landed on Mars in 2012 and has spent its time on the Red Planet making fascinating discoveries about the planet's geology and environment – setting the stage for Perseverance. So, why send another rover to Mars? The lessons we’ve learned from Curiosity coupled with advancements in technology over the last decade are allowing us to take the next big steps in our exploration of Mars, including looking for signs of ancient microbial life, collecting rock samples to bring to Earth one day, and setting the stage for a potential future human mission to the Red Planet.

More specifically, the Perseverance Mars rover has four science objectives:

  • Identify past environments on Mars that could have supported microbial life
  • Seek signs of ancient microbial life within the rocks and soil using a new suite of scientific instruments
  • Collect rock samples of interest to be stored on the surface for possible return by future missions
  • Pave the way for human exploration beyond the Moon

With these science objectives in mind, let's take a look at how the mission is designed to achieve these goals – from its science-rich landing site, Jezero Crater, to its suite of onboard tools and technology.

How It Works

Follow the Water

A false-color satellite image of Jezero Crater is green and yellow around the edges with a large blue circular crater in the middle.

Lighter colors represent higher elevation in this image of Jezero Crater on Mars, the landing site for the Perseverance rover. The black oval indicates the area in which the rover will touch down, also called a landing ellipse. Image Credit: NASA JPL/Caltech/MSSS/JHU-APL/ESA | › Full image and caption

While present-day Mars is a cold, barren planet, science suggests that it was once very similar to Earth. The presence of clay, dried rivers and lakes, and minerals that formed in the presence of water provide extensive evidence that Mars once had flowing water at its surface. As a result, a mission looking for signs of ancient life, also known as biosignatures, should naturally follow that water. That’s because water represents the essential ingredient for life as we know it on Earth, and it can host a wide variety of organisms.

This is what makes Perseverance's landing site in Jezero Crater such a compelling location for scientific exploration. The crater was originally formed by an ancient meteorite impact about 3.8 billion years ago, and it sits within an even larger, older impact basin. The crater also appears to have once been home to an ancient lake fed by a river that formed the delta where Perseverance will begin its exploration, by exploring the foot of the river delta.

Take a tour of Perseverance's landing site in this animated flyover of the Martian surface. Credit: NASA/JPL-Caltech | Watch on YouTube

Tools of the Trade

Once Perseverance has successfully landed, it will begin its scientific exploration with the assistance of an array of tools, also known as science instruments.

An illustration of the rover is shown with each of its science instruments deployed and identified.

This artist's concept shows the various science tools, or instruments, onboard the rover. Image credit: NASA/JPL-Caltech | › Learn more about the rover's science instruments

Like its predecessor, Perseverance will have a number of cameras – 23, in fact! – serving as the eyes of the rover for scientists and engineers back on Earth. Nine of these cameras are dedicated to mobility, or tracking the rover's movements; six will capture images and videos as the rover travels through the Martian atmosphere down to the surface, a process known as entry, descent, and landing; and seven are part of the science instrumentation.

The SuperCam instrument is shown on a laboratory table before being installed on the rover.

SuperCam's mast unit before being installed atop the Perseverance rover's remote sensing mast. The electronics are inside the gold-plated box on the left. The end of the laser peeks out from behind the left side of the electronics. Image credit: CNES | › Learn more about SuperCam

Six pump-like structures control a rectangular metal instrument in this animated image.

PIXL can make slow, precise movements to point at specific parts of a rock's surface so the instrument's X-ray can discover where – and in what quantity – chemicals are distributed in a given sample. This GIF has been considerably sped up to show how the hexapod moves. Image credit: NASA/JPL-Caltech | › Learn more about PIXL

A small camera sits in gold-color housing on a white rover body.

A close-up view of an engineering model of SHERLOC, one the instruments aboard NASA's Perseverance Mars rover. Credit: NASA/JPL-Caltech | › Learn more about SHERLOC

Navcam, located on the mast (or "head") of the rover, will capture images to help engineers control the rover. Meanwhile, Mastcam-Z, also on the rover’s mast, can zoom in, focus, and take 3D color pictures and video at high speed to allow detailed examination of distant objects. A third camera, Supercam, fires a small laser burst to excite compounds on the surface and determine their composition using spectroscopy. Supercam is also equipped with a microphone. This microphone (one of two on the rover) will allow scientists to hear the pop the laser makes upon hitting its target, which may give scientists additional information about the hardness of the rock.

Leaning more toward chemistry, the Planetary Instrument for X-Ray Lithochemistry (PIXL) will allow us to look at the composition of rocks and soil down to the size of a grain of salt. Elements respond to different types of light, such as X-rays, in predictable ways. So by shining an X-ray on Martian rocks and soil, we can identify elements that may be part of a biosignature.

Meanwhile, a device called SHERLOC will look for evidence of ancient life using a technique called Deep UV Raman spectroscopy. Raman spectroscopy can help scientists see the crystallinity and molecular structure of rocks and soil. For example, some molecules and crystals luminesce, or emit light, when exposed to ultraviolet – similar to how a blacklight might be used to illuminate evidence in a crime scene. Scientists have a good understanding of how chemicals considered key to life on Earth react to things like ultraviolet light. So, SHERLOC could help us identify those same chemicals on Mars. In other words, it can contribute to identifying those biosignatures we keep talking about.

Rounding out its role as a roving geologist on wheels, Perseverance also has instruments for studying beneath the surface of Mars. An instrument called the Radar Imager of Mars Subsurface Experiment (RIMFAX) will use ground-penetrating radar to analyze depths down to about 100 feet (30 meters) below the surface. Mounted on the rear of the rover, RIMFAX will help us understand geological features that can't be seen by the other cameras and instruments.

The rover's suite of instruments demonstrates how multiple scientific disciplines – chemistry, physics, biology, geology, and engineering – work in concert to further our understanding of Mars and help scientists uncover whether life ever existed on the Red Planet.

Next Generation Tech

At NASA, scientists and engineers are always looking to push the envelope and, while missions such as Perseverance are ambitious in themselves, they also provide an opportunity for NASA to test new technology that could be used for future missions. Two excellent examples of such technology joining Perseverance on Mars are MOXIE and the first ever Mars helicopter, Ingenuity.

Engineers in white smocks lower a gold-colored cube into the rover

Members of Perseverance mission team install MOXIE into the belly of the rover in the cleanroom at NASA's Jet Propulsion Laboratory in Southern California. Image credit: NASA/JPL-Caltech | › Full image and caption

MOXIE stands for the Mars Oxygen In-Situ Resource Utilization Experiment. Operating at 800 degrees Celsius, MOXIE takes in carbon dioxide (CO2) from the thin Martian atmosphere and splits those molecules into pure oxygen using what is called a catalyst. A catalyst is a chemical that allows for reactions to take place under conditions they normally wouldn’t. MOXIE provides an incredible opportunity for NASA to create something usable out of the limited resources available on Mars. Over the duration of the rover's mission, MOXIE will run for a total of one hour every time it operates, distributed over the course of the prime mission timeframe, to determine whether it can reliably produce breathable oxygen. The goal of operating this way is to allow scientists to determine the performance across a variety of environmental conditions that a dedicated, human-mission-sized oxygen plant would see during operations - day versus night, winter versus summer, etc. Oxygen is of great interest for future missions not just because of its necessity for future human life support on Mars, but also because it can be used as a rocket propellant, perhaps allowing for future small-scale sample return missions to Earth.

The helicopter with four long blades, a cube-shape body and long skinny legs sites in the forground with the wheels of the rover visible to its right.

This artist's concept shows Ingenuity, the first Mars helicopter, on the Red Planet's surface with Perseverance (partially visible on the left) in the distance. Image credit: NASA/JPL-Caltech | › Full image and caption

The Mars Ingenuity helicopter is likewise an engineering first. It is a technology demonstration to test powered flight on Mars. Because the Martian atmosphere is so thin, flight is incredibly difficult. So, the four-pound (1.8-kilogram), solar powered helicopter is specially designed with two, four-foot (1.2-meter) long counter-rotating blades that spin at 2,400 rotations per minute. In the months after Perseverance lands, Ingenuity will drop from the belly of the rover. If all goes well, it will attempt test flights of increasing difficulty, covering incrementally greater heights and distances for about 30 days. In the future, engineers hope flying robots can allow for a greater view of the surrounding terrain for robotic and human missions alike.

Teach It

Take part in a worldwide “teachable moment” and bring students along for the ride as NASA lands the Perseverance rover on Mars February 18. Science communicator and host of “Emily’s Wonder Lab” on Netflix, Emily Calandrelli, shares how you can join the adventure with your students! | Register on Eventbrite

The process of landing on Mars with such an advanced mission is no doubt an exciting opportunity to engage students across all aspects of STEM – and NASA wants to help teachers, educators and families bring students along for the adventure with the Mission to Mars Student Challenge. This challenge will lead students through designing and building a mission to Mars with a guided education plan and resources from NASA, joining in live stream Q&As with experts, and sharing student work with a worldwide audience. The challenge culminates on Feb. 18, when students can land their missions along with the Perseverance Mars rover!

Register on Eventbrite to receive:

  • A guided five-week education plan for elementary, middle, and high school students with standards-aligned STEM lessons and activities from NASA. Plans are flexible with your schedule and can be completed in whole or in part or in any sequence.
  • A weekly newsletter with links to tips and resources related to the mission phase of the week.
  • Video conversations with mission scientists and engineers highlighting how their work relates to what students are learning – plus, ideas to kick-start the weekly challenge.
  • Opportunities to participate in Q&As with mission experts and submit student questions and work that could be featured during NASA broadcasts leading up to and on landing day.

Learn more about the challenge and explore additional education resources related to the Perseverance Mars rover mission at https://go.nasa.gov/mars-challenge

Watch the Landing

The next chapter of Perseverance’s journey takes place on Feb. 18 at 12 p.m. PST (3 p.m. EST), when the mission reaches Mars after seven months of travelling through space. Join NASA as we countdown to landing with online events for teachers, students, and space enthusiasts! The landing day broadcast can be seen on NASA TV and the agency's website starting at 11:15 a.m. PST (2:15 p.m. EST). For a full listing of online events leading up to and on landing day, visit the mission's Watch Online page.

Follow landing updates on NASA's Twitter, Facebook and Instagram accounts.

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More Resources From NASA

  • Website: Perseverance Mars Rover
  • Website: NASA Mars Exploration
  • Website: Space Place - All About Mars
  • Video: Perseverance Mission Landing Trailer
  • Profiles: Meet the Martians
  • Simulation: Fly Along with Perseverance in Real-Time
  • Virtual Events: Watch Online – NASA Mars Exploration
  • Videos: Mars exploration videos from NASA
  • Images: Mars exploration images and graphics from NASA
  • Articles: Articles about Mars exploration from NASA
  • Share: Social Media
  • TAGS: Mars, Perseverance, Mars 2020, Science, Engineering, Robotics, Educators, Teachers, Students, Teachable Moments, Teach, Learn, Mars Landing

    • Brandon Rodriguez
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    Collage of images and graphics representing the science goals of the Sentinel-6 Michael Freilich mission

    Learn about the mission and find out how to make classroom connections to NASA Earth science – plus explore related teaching and learning resources.


    In the News

    A new spacecraft that will collect vital sea-surface measurements for better understanding climate change and improving weather predictions is joining the fleet of Earth science satellites monitoring our changing planet from space. A U.S.-European partnership, the Sentinel-6 Michael Freilich satellite continues a long tradition of collecting scientific data from Earth orbit. It’s named in honor of NASA’s former Earth Science Division director and a leading advocate for ocean measurements from space.

    Read on to find out how the mission will measure sea-surface height for the next 10 years and provide atmospheric data to help better predict weather. Plus, find out how to watch the launch online and explore related teaching resources to bring NASA Earth science into the classroom and incorporate sea level data into your instruction.

    How It Works

    The Sentinel-6 Michael Freilich satellite is designed to measure sea-surface height and improve weather predictions. Once in orbit, it will be able to measure sea-surface height – with accuracy down to the centimeter – over 90% of the world’s oceans every 10 days. It will do this using a suite of onboard science tools, or instruments.

    To measure sea-surface height, a radar altimeter will send a pulse of microwave energy to the ocean’s surface and record how long it takes for the energy to return. The time it takes for the signal to return varies depending on the height of the ocean – a higher ocean surface results in a shorter return time, while a lower ocean surface results in a longer return time. A microwave radiometer will measure delays that take place as the signal travels through the atmosphere to correct for this effect and provide an even more precise measurement of sea-surface height.

    A blue beam extends from the spacecraft down toward Earth as a red dot pulses back and forth between the spacecraft and the surface of the planet.

    This animation shows the radar pulse from the Sentinel-6 Michael Freilich satellite's altimeter bouncing off the sea surface in order to measure the height of the ocean. Image credit: NASA/JPL-Caltech | + Expand image

    To measure atmospheric data, Sentinel-6 Michael Freilich is equipped with the Global Navigation Satellite System - Radio Occultation, or GNSS-RO, instrument, which will measure signals from GPS satellites – the same ones you use to navigate on Earth. As these satellites move below or rise above the horizon from Sentinel-6 Michael Freilich's perspective, their signals slow down, change frequency and bend as a result of the phenomenon known as refraction. Scientists can use these changes in the GPS signal to measure small shifts in temperature, moisture content, and density in the atmosphere. These measurements can help meteorologists improve weather forecasts.

    Why It's Important

    Scientists from around the world have been collecting sea level measurements for more than a century. The data – gathered from tide gauges, sediment cores, and space satellites – paint a clear picture: sea level is rising. Looking at the average height of the sea across the planet, we see that in the last 25 years global sea level has been rising an average of 0.13 inches (3.3 mm) per year. This average is increasing each year (in the 2000s, it was 0.12 inches, or 3.0 mm, per year) as is the rate at which it’s increasing. That means that sea level is rising, and it’s rising faster and faster. Since 1880, global sea level has risen more than eight inches (20 cm). By 2100, it is projected to rise another one to four feet (30 to 122 cm).

    This satellite data show the change in Earth's global sea level since 1993. Roll over the chart to see the various data points. For more Earth vital signs, visit NASA's Global Climate Change website

    Measuring sea level from space provides scientists with global measurements of Earth’s oceans in a matter of days, including areas far from shore where measurements aren’t practical or possible. Starting in 1992 with the launch of the TOPEX/Poseidon mission, the record of sea level measurements from space has continued uninterrupted, providing an increasingly detailed picture of Earth’s rising seas. The Sentinel-6 Michael Freilich satellite – and its twin, which will launch in 2025 – will extend those measurements to 2030, allowing scientists to continue collecting vital information about Earth’s changing oceans and climate.

    Unlike previous satellites that measured sea level, Sentinel-6 Michael Freilich has the capability to measure sea level variations more accurately near coastlines, giving scientists insight into changes that can have direct impacts on communities and livelihoods, such as commercial fishing and ship navigation.

    This playlist for students and teachers features explainers about the causes and effects of sea level rise and how NASA is studying our changing planet – plus related STEM activities and experiments for students. | Watch on YouTube

    With rising seas already impacting people and communities, it's important to understand not just how much seas are rising, but also where and how quickly they are rising. Data from instruments on Sentinel-6 Michael Freilich can be combined with data from other satellites to get a clearer picture of what's contributing to sea level rise and where. For example, by looking at the satellite's radar altimeter measurements along with gravity measurements from the GRACE-FO mission, scientists can better determine how melting ice and thermal expansion are contributing to sea level rise. And by tracking the movement of warm water (which stands taller than cold water), scientists can better predict the rapid expansion of hurricanes.

    Watch the Launch

    Scheduled to launch at 9:17 a.m. PST (12:17 p.m. EST) on November 21, Sentinel-6 Michael Freilich will launch atop a SpaceX Falcon 9 rocket from Vandenberg Air Force Base in California.

    Watch a live broadcast of the launch from the Vandenberg Air Force Base on NASA TV and the agency’s website. Visit the Sentinel-6 Michael Freilich website to explore more news about the mission. Follow launch updates on NASA's Twitter, Facebook and Instagram accounts.

    Teach It

    Make classroom connections to NASA Earth science with lessons about rising seas, thermal expansion and ice melt, data collection and graphing, and engineering. Plus explore independent activities and experiments students can do at home, video playlists, and more:

    Explore More

    Recursos en Español

    TAGS: Teachable Moments, Educators, Teachers, Parents, K-12 Education, Launch, Mission, Earth, Satellite, Earth Science, Climate Change, Sentinel-6 Michael Freilich, Sea Level, Sea Level Rise,

    • Lyle Tavernier
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    Satellite Image of smoke above the Western U.S.

    Data overlayed on a satellite image of the United States shows a thick cloud of aerosols over the western US

    Animated satellite image of Earth

    Update: Sept. 14, 2020 – This feature, originally published on Aug. 23, 2016, has been updated to include information on the 2020 fires and current fire research.


    In the News

    Once again, it’s fire season in the western United States with many citizens finding themselves shrouded in wildfire smoke. Late summer in the West brings heat, low humidity, and wind – optimal conditions for fire. These critical conditions have resulted in the August Complex Fire, the largest fire in California's recorded history. Burning concurrently in California are numerous other wildfires, including the SCU Lightning Complex fire, the third-largest in California history.

    Fueled by high temperatures, low humidity, high winds, and years of vegetation-drying drought, more than 7,700 fires have engulfed over 3 million acres across California already this year. And the traditional fire season – the time of year when fires are more likely to start, spread, and consume resources – has only just begun.

    Because of their prevalence and effects on a wide population, wildfires will remain a seasonal teachable moment for decades to come. Keep reading to find out how NASA studies wildfires and their effects on climate and communities. Plus, explore lessons to help students learn more about fires and their impacts.

    How It Works

    With wildfires starting earlier in the year and continuing to ignite throughout all seasons, fire season is now a year-round affair not just in California, but also around the world. In fact, the U.S. Forest Service found that fire seasons have grown longer in 25 percent of Earth's vegetation-covered areas.

    Animation of the FireSat network of satellites capturing wildfires on Earth

    This animation shows how FireSat would use a network of satellites around the Earth to detect fires faster than ever before. | + Expand image

    For NASA's Jet Propulsion Laboratory, which is located in Southern California, the fires cropping up near and far are a constant reminder that its efforts to study wildfires around the world from space, the air, and on the ground are as important as ever.

    JPL uses a suite of Earth satellites and airborne instruments to help better understand fires and aide in fire management and mitigation. By looking at multiple images and types of data from these instruments, scientists compare what a region looked like before, during, and after a fire, as well as how long the area takes to recover.

    While the fire is burning, scientists watch its behavior from an aerial perspective to get a big-picture view of the fire itself and the air pollution it is generating in the form of smoke filled with carbon monoxide and carbon dioxide.

    Natasha Stavros, a wildfire expert at JPL, joined Zach Tane with the U.S. Forest Service during a Facebook Live event to discuss some of these technologies and how they're used to understand wildfire behavior and improve wildfire recovery.

    Additionally, JPL worked with a startup in San Francisco called Quadra Pi R2E to develop FireSat, a global network of satellites designed to detect wildfires and alert firefighting crews faster. 

    Using these technologies, NASA scientists are gaining a broader understanding of fires and their impacts.

    Why It's Important

    One of the ways we often hear wildfires classified is by how much area they have burned. Though this is certainly of some importance, of greater significance to fire scientists is the severity of the fire. Wildfires are classified as burning at different levels of severity: low, medium, and high. Severity is a function of intensity, or how hot the fire was, and its spread rate, or the speed at which it travels. A high-severity fire is going to do some real damage. (Severity is measured by the damage left after the fire, but can be estimated during a fire event by calculating spread rate and measuring flame height which indicates intensity.)

    Google Earth image showing fire severity
    This image, created using data imported into Google Earth, shows the severity of the 2014 King Fire. Green areas are unchanged by the fire; yellow equals low severity; orange equals moderate severity; and red equals high severity. A KMZ file with this data is available in the Fired Up Over Math lesson linked below. Credit: NASA/JPL-Caltech/E. Natasha Stavros.

    The impacts of wildfires range from the immediate and tangible to the delayed and less obvious. The potential for loss of life, property, and natural areas is one of the first threats that wildfires pose. From a financial standpoint, fires can lead to a downturn in local economies due to loss of tourism and business, high costs related to infrastructure restoration, and impacts to federal and state budgets.

    The release of greenhouse gases like carbon dioxide and carbon monoxide is also an important consideration when thinking about the impacts of wildfires. Using NASA satellite data, researchers at the University of California, Berkeley, determined that between 2001 and 2010, California wildfires emitted about 46 million tons of carbon, around five to seven percent of all carbon emitted by the state during that time period.

    Animation showing Carbon Dioxide levels rising from the Station Fire in Southern California.
    This animation from NASA's Eyes on the Earth visualization program shows carbon monoxide rising (red is the highest concentration) around Southern California as the Station Fire engulfed the area near JPL in 2009. Image credit: NASA/JPL-Caltech

    In California and the western United States, longer fire seasons are linked to changes in spring rains, vapor pressure, and snowmelt – all of which have been connected to climate change. Wildfires serve as a climate feedback loop, meaning certain effects of wildfires – the release of CO2 and CO – contribute to climate change, thereby enhancing the factors that contribute to longer and stronger fire seasons.

    While this may seem like a grim outlook, it’s worth noting that California forests still act as carbon sinks – natural environments that are capable of absorbing carbon dioxide from the atmosphere. In certain parts of the state, each hectare of redwood forest is able to store the annual greenhouse gas output of 500 Americans.

    Studying and managing wildfires is important for maintaining resources, protecting people, properties, and ecosystems, and reducing air pollution, which is why JPL, NASA, and other agencies are continuing their study of these threats and developing technologies to better understand them.

    Teach It

    Have your students try their hands at solving some of the same fire-science problems that NASA scientists do with these two lessons that get students in grades 3 through 12 using NASA data, algebra, and geometry to approximate burn areas, fire-spread rate and fire intensity:

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    Lyle Tavernier contributed to this feature.

    TAGS: teachable moments, wildfires, science, Earth Science, Earth, Climate Change

    • Ota Lutz
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    Artist's concept of the Perseverance rover on Mars

    Update: July 6, 2020 – Due to processing delays in preparations to unite the spacecraft with the rocket, the first launch attempt will be no earlier than July 30 at 4:50 a.m. PDT (7:50 a.m. EDT). The launch period has been expanded to Aug. 15. Dates updated below. › Read more


    Perseverance, NASA's most advanced Mars rover yet, is scheduled to leave Earth for its seven-month journey to the Red Planet this summer.

    Only the fifth NASA rover destined for Mars, Perseverance is designed to build on the work and scientific discoveries of its predecessors. Find out more about the rover's science goals and new technologies below. Plus, learn how you can bring the exciting engineering and science of this mission to students with lessons and DIY projects covering topics like biology, geology, physics, mathematics, engineering, coding and language arts.

    Why It's Important

    Perseverance may look similar to Curiosity – the NASA rover that's been exploring Mars since 2012 – but the latest rover's new science instruments, upgraded cameras, improved onboard computers and new landing technologies make it uniquely capable of accomplishing the science goals planned for the mission.

    Diagram of the Perseverance Mars rover's science instruments. Credit: NASA/JPL-Caltech | + Expand image

    Looking for signs of habitability

    The first of the rover's four science goals deals with studying the habitability of Mars. The mission is designed to look for environments that could have supported life in the past.

    Perseverance will land in Jezero Crater, a 28-mile-wide (45-kilometer-wide) crater that scientists believe was once filled with water. Data from orbiters at the Red Planet suggest that water once flowed into the crater, carrying clay minerals from the surrounding area, depositing them in the crater and forming a delta. We find similar conditions on Earth, where the right combination of water and minerals can support life. By comparing these to the conditions we find on Mars, we can better understand the Red Planet's ability to support life. The Perseverance rover is specially designed to study the habitability of Mars' Jezero Crater using a suite of scientific instruments, or tools, that can evaluate the environment and the processes that influence it.

    This animated flyover shows the area where Perseverance will land in February 2021 and is narrated by the mission's project scientist, Ken Farley. Credit: NASA/JPL-Caltech | › Learn more about the mission's landing site | Watch on YouTube

    Seeking signs of ancient life

    The rover's second science goal is closely linked with its first: Perseverance will seek out evidence that microbial life once existed on Mars in the past. In doing so, the mission could make progress in understanding the origin, evolution and distribution of life in the universe – the scientific field known as astrobiology.

    It's important to note that the rover won't be looking for present-day life. Instead, its instruments are designed to look for clues left behind by ancient life. We call those clues biosignatures. A biosignature might be a pattern, object or substance that was created by life in the past and can be identified by certain properties, such as chemical composition, mineralogy or structure.

    To better understand if a possible biosignature is really a clue left behind by ancient life, we need to look for biosignatures and study the habitability of the environment. Discovering that an environment is habitable does not automatically mean life existed there and some geologic processes can leave behind biosignature-like signs in non-habitable environments.

    Collecting samples

    Perseverance's third science goal is to gather samples of Martian rocks and soil. The rover will leave the samples on Mars, where future missions could collect them and bring them back to Earth for further study.

    Scientists can learn a lot about Mars with a rover like Perseverance that can take in situ (Latin for "on-site") measurements. But examining samples from Mars in full-size laboratories on Earth can provide far more information about whether life ever existed on Mars than studying them on the Martian surface.

    Perseverance will take the first step toward making a future sample return possible. The rover is equipped with special coring drill bits that will collect scientifically interesting samples similar in size to a piece of chalk. Each sample will be capped and sealed in individual collection tubes. The tubes will be stored aboard the rover until the mission team determines the best strategic locations on the planet's surface to leave them. The collection tubes will stay on the Martian surface until a potential future campaign collects them for return to Earth. NASA and the European Space Agency are solidifying concepts for the missions that will complete this campaign.

    Preparing for future astronauts

    Astronauts, an exploration vehicle and a habitat are shown among a rich orange landscape

    This artist's concept depicts astronauts and human habitats on Mars. The Perseverance Mars rover will carry a number of technologies that could pave the way for astronauts to explore Mars. Credit: NASA | + Expand image

    Like the robotic spacecraft that landed on the Moon to prepare for the Apollo astronauts, the Perseverance rover's fourth science goal will help pave the way for humans to eventually visit Mars.

    Before humans can set foot on the Red Planet, we need to know more about conditions there and demonstrate that technologies needed for returning to Earth, and survival, will work. That’s where MOXIE comes in. Short for Mars Oxygen In-Situ Resource Utilization Experiment, MOXIE is designed to separate oxygen from carbon dioxide (CO2) in Mars' atmosphere. The atmosphere that surrounds the Red Planet is 96% CO2. But there's very little oxygen – only 0.13%, compared with the 21% in Earth’s atmosphere.

    Oxygen is a crucial ingredient in rocket fuel and is essential for human survival. MOXIE could show how similar systems sent to Mars ahead of astronauts could generate rocket fuel to bring astronauts back to Earth and even create oxygen for breathing.

    Join JPL mechanical engineer Mike Meacham to find out how the MOXIE instrument on NASA's Perseverance Mars rover is designed to convert carbon dioxide from Mars' atmosphere into oxygen. Credit: NASA/JPL-Caltech | Watch on YouTube

    Flying the first Mars helicopter

    Joining the Perseverance rover on Mars is the first helicopter designed to fly on another planet. Dubbed Ingenuity, the Mars Helicopter is a technology demonstration that will be the first test of powered flight on another planet.

    The lightweight helicopter rides to Mars attached to the belly of the rover. After Perseverance is on Mars, the helicopter will be released from the rover and will attempt up to five test flights in the thin atmosphere of Mars. After a successful first attempt at lifting off, hovering a few feet above the ground for 20 to 30 seconds and landing, the operations team can attempt incrementally higher and longer-distance flights. Ingenuity is designed to fly for up to 90 seconds, reach an altitude of 15 feet and travel a distance of nearly 980 feet. Sending commands to the helicopter and receiving information about the flights relayed through the rover, the helicopter team hopes to collect valuable test data about how the vehicle performs in Mars’ thin atmosphere. The results of the Mars Helicopter's test flights will help inform the development of future vehicles that could one day explore Mars from the air. Once Ingenuity has completed its technology demonstration, Perseverance will continue its mission on the surface of the Red Planet.

    Join JPL mechanical engineer Mike Meacham to learn about the first helicopter designed for Mars. Credit: NASA/JPL-Caltech | Watch on YouTube

    How It Works

    Before any of that can happen, the Perseverance Mars rover needs to successfully lift off from Earth and begin its journey to the Red Planet. Here's how the launch is designed to ensure that the spacecraft and Mars are at the same place on landing day.

    About every 26 months, Mars and Earth are at points in their orbits around the Sun that allow us to launch spacecraft to Mars most efficiently. This span of time, called a launch period, lasts several weeks. For Perseverance, the launch period is targeted to begin at 4:50 a.m. PDT (7:50 a.m. EDT) on July 30 and end on Aug. 15. Each day, there is a launch window lasting about two hours. If all conditions are good, we have liftoff! If there's a little too much wind or other inclement weather, or perhaps engineers want to take a look at something on the rocket during the window, the countdown can be paused, and teams will try again the next day.

    Regardless of when Perseverance launches during this period, the rover will land on Mars on Feb. 18, 2021, at around 12:30 PST. Engineers can maintain this fixed landing date because when the rover launches, it will go into what's called a parking orbit around Earth. Depending on when the launch happens, the rover will coast in the temporary parking orbit for 24 to 36 minutes. Then, the upper stage of the rocket will ignite for about seven minutes, giving the spacecraft the velocity it needs to reach Mars.

    Like the Curiosity rover, Perseverance will launch from Launch Complex 41 at Cape Canaveral Air Force Station in Florida on an Atlas V 541 rocket – one of the most powerful rockets available for interplanetary spacecraft.

    Watch a live broadcast of the launch from the Kennedy Space Center on NASA TV and the agency’s website. Visit the Perseverance rover mission website to explore a full listing of related virtual events and programming, including education workshops, news briefings and conversations with mission experts. Follow launch updates on NASA's Twitter, Facebook and Instagram accounts.

    Teach It

    The launch of NASA's next Mars rover and the first Mars Helicopter is a fantastic opportunity to engage students in real-world problem solving across the STEM fields. Check out some of the resources below to see how you can bring NASA missions and science to students in the classroom and at home.

    Virtual Education Workshops

    Lessons for Educators

    Activities for Students

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    TAGS: Mars, Mars 2020, Perseverance, Mars Rover, launch, Teach, teachers, educators, parents, lessons, activities, resources, K-12, STEM, events, students, science, engineering

    • Lyle Tavernier
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    Illustration of spacecraft on a light purple background that reads "NASA Pi Day Challenge"

    Update: March 16, 2020 – The answers to the 2020 NASA Pi Day Challenge are here! View the illustrated answer key (also available as a text-only doc).


    In the News

    Our annual opportunity to indulge in a shared love of space exploration, mathematics and sweet treats has come around again! Pi Day is the March 14 holiday that celebrates the mathematical constant pi – the number that results from dividing any circle's circumference by its diameter.

    Infographic of all of the Pi in the Sky 7 graphics and problems

    Visit the Pi in the Sky 7 lesson page to explore classroom resources and downloads for the 2019 NASA Pi Day Challenge. Image credit: NASA/JPL-Caltech | + Expand image

    Overhead view of Mars with a comparison of the smaller landing ellipse made possible by Range Trigger technology

    A new Mars landing technique called Range Trigger is reducing the size of the ellipse where spacecraft touch down. Image credit: NASA/JPL-Caltech | › Full image and caption

    Composite image of the Kuiper Belt object Arrokoth from NASA's New Horizons spacecraft. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko | › Full image and caption

    Diagram of an airplane flying over a section of ocean with an example of the spectral data that CORAL collects

    The CORAL mission records the spectra of light reflected from the ocean to study the composition and health of Earth's coral reefs. Image credit: NASA | + Expand image

    Rays of bright orange and red shoot out diagonally from a blue circle surrounding the star Beta Pictoris

    The star Beta Pictoris and its surrounding debris disk in near-infrared light. Image credit: ESO/A.-M. Lagrange et al. | › Full image and caption

    Besides providing an excuse to eat all varieties of pie, Pi Day gives us a chance to appreciate some of the ways NASA uses pi to explore the solar system and beyond. You can do the math for yourself – or get students doing it – by taking part in the NASA Pi Day Challenge. Find out below how to test your pi skills with real-world problems faced by NASA space explorers, plus get lessons and resources for educators.

    How It Works

    The ratio of any circle's circumference to its diameter is equal to pi, which is often rounded to 3.14. But pi is what is known as an irrational number, so its decimal representation never ends, and it never repeats. Though it has been calculated to trillions of digits, we use far fewer at NASA.

    Pi is useful for all sorts of things, like calculating the circumference and area of circular objects and the volume of cylinders. That's helpful information for everyone from farmers irrigating crops to tire manufacturers to soup-makers filling their cans. At NASA, we use pi to calculate the densities of planets, point space telescopes at distant stars and galaxies, steer rovers on the Red Planet, put spacecraft into orbit and so much more! With so many practical applications, it's no wonder so many people love pi!

    In the U.S., 3.14 is also how we refer to March 14, which is why we celebrate the mathematical marvel that is pi on that date each year. In 2009, the U.S. House of Representatives passed a resolution officially designating March 14 as Pi Day and encouraging teachers and students to celebrate the day with activities that teach students about pi.

    The NASA Pi Day Challenge

    This year's NASA Pi Day Challenge poses four puzzlers that require pi to compare the sizes of Mars landing areas, calculate the length of a year for one of the most distant objects in the solar system, measure the depth of the ocean from an airplane, and determine the diameter of a distant debris disk. Learn more about the science and engineering behind the problems below or click the link to jump right into the challenge.

    › Take the NASA Pi Day Challenge
    › Educators, get the lesson here!

    Mars Maneuver

    Long before a Mars rover touches down on the Red Planet, scientists and engineers must determine where to land. Rather than choosing a specific landing spot, NASA selects an area known as a landing ellipse. A Mars rover could land anywhere within this ellipse. Choosing where the landing ellipse is located requires compromising between getting as close as possible to interesting science targets and avoiding hazards like steep slopes and large boulders, which could quickly bring a mission to its end. In the Mars Maneuver problem, students use pi to see how new technologies have reduced the size of landing ellipses from one Mars rover mission to the next.

    Cold Case

    In January 2019, NASA's New Horizons spacecraft sped past Arrokoth, a frigid, primitive object that orbits within the Kuiper Belt, a doughnut-shaped ring of icy bodies beyond the orbit of Neptune. Arrokoth is the most distant Kuiper Belt object to be visited by a spacecraft and only the second object in the region to have been explored up close. To get New Horizons to Arrokoth, mission navigators needed to know the orbital properties of the object, such as its speed, distance from the Sun, and the tilt and shape of its orbit. This information is also important for scientists studying the object. In the Cold Case problem, students can use pi to determine how long it takes the distant object to make one trip around the Sun.

    Coral Calculus

    Coral reefs provide food and shelter to many ocean species and protect coastal communities against extreme weather events. Ocean warming, invasive species, pollutants, and acidification caused by climate change can harm the tiny living coral organisms responsible for building coral reefs. To better understand the health of Earth's coral reefs, NASA's COral Reef Airborne Laboratory, or CORAL, mission maps them from the air using spectroscopy, studying how light interacts with the reefs. To make accurate maps, CORAL must be able to differentiate among coral, algae and sand on the ocean floor from an airplane. And to do that, it needs to calculate the depth of the ocean at every point it maps by measuring how much sunlight passes through the ocean and is reflected upward from the ocean floor. In Coral Calculus, students use pi to measure the water depth of an area mapped by the CORAL mission and help scientists better understand the status of Earth's coral reefs.

    Planet Pinpointer

    Our galaxy contains billions of stars, many of which are likely home to exoplanets – planets outside our solar system. So how do scientists decide where to look for these worlds? Using data gathered by NASA's Spitzer Space Telescope, researchers found that they're more likely to find giant exoplanets around young stars surrounded by debris disks, which are made up of material similar to what's found in the asteroid belt and Kuiper Belt in our solar system. Sure enough, after discovering a debris disk around the star Beta Pictoris, researchers later confirmed that it is home to at least two giant exoplanets. Learning more about Beta Pictoris' debris disk could give scientists insight into the formation of these giant worlds. In Planet Pinpointer, put yourself in the role of a NASA scientist to learn more about Beta Pictoris' debris disk, using pi to calculate the distance across it.

    Participate

    Join the conversation and share your Pi Day Challenge answers with @NASAJPL_Edu on social media using the hashtag #NASAPiDayChallenge

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    TAGS: K-12 Education, Math, Pi Day, Pi, NASA Pi Day Challenge, Events, Space, Educators, Teachers, Parents, Students, STEM, Lessons, Problem Set, Mars 2020, Perseverance, Curiosity, Mars rovers, Mars landing, MU69, Arrokoth, New Horizons, Earth science, Climate change, CORAL, NASA Expeditions, coral reefs, oceans, Spitzer, exoplanets, Beta Pictoris, stars, universe, space telescope

    • Lyle Tavernier
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    In the News

    On Jan. 30, 2020, the venerable Spitzer Space Telescope mission will officially come to an end as NASA makes way for a next-generation observatory. For more than 16 years, Spitzer has served as one of NASA’s four Great Observatories, surveying the sky in infrared. During its lifetime, Spitzer detected planets and signs of habitability beyond our solar system, returned stunning images of regions where stars are born, spied light from distant galaxies formed when the universe was young, and discovered a huge, previously-unseen ring around Saturn. Read on to learn more about this amazing mission and gather tools to teach your students that there truly is more than meets the eye in the infrared universe!

    How It Worked

    Human eyes can see only the portion of the electromagnetic spectrum known as visible light. This is because the human retina can detect only certain wavelengths of light through special photoreceptors called rods and cones. Everything we see with our eyes either emits or reflects visible light. But visible light is just a small portion of the electromagnetic spectrum. To "see" things that emit or reflect other wavelengths of light, we must rely on technology designed to sense those portions of the electromagnetic spectrum. Using this specialized technology allows us to peer into space and observe objects and processes we wouldn’t otherwise be able to see.

    Infographic showing the electromagnetic spectrum and applications for various wavelengths.

    This diagram shows wavelengths of light on the electromagnetic spectrum and how they're used for various applications. Image credit: NASA | + Expand image

    Infrared is one of the wavelengths of light that cannot be seen by human eyes. (It can sometimes be felt by our skin as heat if we are close enough to a strong source.) All objects that have temperature emit many wavelengths of light. The warmer they are, the more light they emit. Most things in the universe are warm enough to emit infrared radiation, and that light can be seen by an infrared-detecting telescope. Because Earth’s atmosphere absorbs most infrared radiation, infrared observations of space are best conducted from outside the planet's atmosphere.

    Learn more about the infrared portion of the electromagnetic spectrum and how NASA uses it to explore space. Credit: NASA/JPL-Caltech | Watch on YouTube

    So, to get a look at space objects that were otherwise hidden from view, NASA launched the Spitzer Space Telescope in 2003. Cooled by liquid helium and capable of viewing the sky in infrared, Spitzer launched into an Earth-trailing orbit around the Sun, where it became part of the agency's Great Observatory program along with the visible-light and near-infrared-detecting Hubble Space Telescope, Compton Gamma-Ray Observatory and Chandra X-ray Observatory. (Keeping the telescope cold reduces the chances of heat, or infrared light, from the spacecraft interfering with its astronomical observations.)

    Over its lifetime, Spitzer has been used to detect light from objects and regions in space where the human eye and optical, or visible-light-sensing, telescopes may see nothing.

    Why It's Important

    NASA's Spitzer Space Telescope has returned volumes of data, yielding numerous scientific discoveries.

    Vast, dense clouds of dust and gas block our view of many regions of the universe. Infrared light can penetrate these clouds, enabling Spitzer to peer into otherwise hidden regions of star formation, newly forming planetary systems and the centers of galaxies.

    A whisp of orange and green dust bows out beside a large blue star among a field of smaller blue stars.

    The bow shock, or shock wave, in front of the giant star Zeta Ophiuchi shown in this image from Spitzer is visible only in infrared light. The bow shock is created by winds that flow from the star, making ripples in the surrounding dust. Image credit: NASA/JPL-Caltech | › Full image and caption

    Infrared astronomy also reveals information about cooler objects in space, such as smaller stars too dim to be detected by their visible light, planets beyond our solar system (called exoplanets) and giant molecular clouds where new stars are born. Additionally, many molecules in space, including organic molecules thought to be key to life's formation, have unique spectral signatures in the infrared. Spitzer has been able to detect those molecules when other instruments have not.

    Bursts of reds, oranges, greens, blues and violets spread out in all directions from a bright center source. Reds and oranges dominate the left side of the image.

    Both NASA's Spitzer and Hubble space telescopes contributed to this vibrant image of the Orion nebula. Spitzer's infrared view exposed carbon-rich molecules, shown in this image as wisps of red and orange. Image credit: NASA/JPL-Caltech/T. Megeath (University of Toledo) & M. Robberto (STScI) | › Full image and caption

    Stars are born from condensing clouds of dust and gas. These newly formed stars are optically visible only once they have blown away the cocoon of dust and gas in which they were born. But Spitzer has been able to see infant stars as they form within their gas and dust clouds, helping us learn more about the life cycles of stars and the formation of solar systems.

    A blanket of green- and orange-colored stellar dust surrounds a grouping of purple, blue and red stars.

    Newborn stars peek out from beneath their natal blanket of dust in this dynamic image of the Rho Ophiuchi dark cloud from Spitzer. The colors in this image reflect the relative temperatures and evolutionary states of the various stars. The youngest stars are shown as red while more evolved stars are shown as blue. Image credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA | › Full image and caption

    Infrared emissions from most galaxies come primarily from stars as well as interstellar gas and dust. With Spitzer, astronomers have been able to see which galaxies are furiously forming stars, locate the regions within them where stars are born and pinpoint the cause of the stellar baby boom. Spitzer has given astronomers valuable insights into the structure of our own Milky Way galaxy by revealing where all the new stars are forming.

    A bright band of crimson-colored dust stretches across the center of this image covered in tiny specs of light from hundreds of thousands of stars.

    This Spitzer image, which covers a horizontal span of 890 light-years, shows hundreds of thousands of stars crowded into the swirling core of our spiral Milky Way galaxy. In visible-light pictures, this region cannot be seen at all because dust lying between Earth and the galactic center blocks our view. Image credit: NASA/JPL-Caltech | › Full image and caption

    Spitzer marked a new age in the study of planets outside our solar system by being the first telescope to directly detect light emitted by these so-called exoplanets. This has made it possible for us to directly study and compare these exoplanets. Using Spitzer, astronomers have been able to measure temperatures, winds and the atmospheric composition of exoplanets – and to better understand their potential habitability. The discoveries have even inspired artists at NASA to envision what it might be like to visit these planets.

    Collage of exoplanet posters from NASA

    Thanks to Spitzer, scientists are learning more and more about planets beyond our solar system. These discoveries have even inspired a series of posters created by artists at NASA, who imagined what future explorers might encounter on these faraway worlds. Image credit: NASA/JPL-Caltech | › Download posters

    Data collected by Spitzer will continue to be analyzed for decades to come and is sure to yield even more scientific findings. It's certainly not the end of NASA's quest to get an infrared window into our stellar surroundings. In the coming years, the agency plans to launch its James Webb Space Telescope, with a mirror more than seven times the diameter of Spitzer's, to see the universe in even more detail. And NASA's Wide Field Infrared Survey Telescope, or WFIRST, will continue infrared observations in space with improved technology. Stay tuned for even more exciting infrared imagery, discoveries and learning!

    Teach It

    Use these lessons, videos and online interactive features to teach students how we use various wavelengths of light, including infrared, to learn about our universe:


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    Also, check out these related resources for kids from NASA’s Space Place:

    TAGS: Teachable Moments, science, astronomy, K-12 education, teachers, educators, parents, STEM, lessons, activities, Spitzer, Space Telescope, Missions, Spacecraft, Stars, Galaxies, Universe, Infrared, Wavelengths, Spectrum, Light

    • Ota Lutz
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    Collage of images and illustrations of planets, spacecraft and space objects

    Whether discovering something about our own planet or phenomena billions of miles away, NASA missions and scientists unveiled a vast universe of mysteries this past decade. And with each daring landing, visit to a new world and journey into the unknown came new opportunities to inspire the next generation of explorers. Read on for a look at some of NASA's most teachable moments of the decade from missions studying Earth, the solar system and beyond. Plus, find out what's next in space exploration and how to continue engaging students into the 2020s with related lessons, activities and resources.

    1. Earth's Changing Climate

    Flat map of Earth with an animation of co2 data overlayed

    Rising sea levels, shrinking ice caps, higher temperatures and extreme weather continued to impact our lives this past decade, making studying Earth’s changing climate more important than ever. During the 2010s, NASA and National Oceanic and Atmospheric Administration, or NOAA, led the way by adding new Earth-monitoring satellites to their fleets to measure soil moisture and study carbon dioxide levels. Meanwhile, satellites such as Terra and Aqua continued their work monitoring various aspects of the Earth system such as land cover, the atmosphere, wildfires, water, clouds and ice. NASA's airborne missions, such as Operation IceBridge, Airborne Snow Observatory and Oceans Melting Greenland, returned data on water movement, providing decision makers with more accurate data than ever before. But there's still more to be done in the future to understand the complex systems that make up Earth's climate and improve the scientific models that will help the world prepare for a warmer future. Using these missions and the science they're gathering as a jumping-off point, students can learn about the water cycle, build data-based scientific models and develop an understanding of Earth's energy systems.

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    2. Teachable Moments in the Sky

    Animated image of the Moon during a lunar eclipse

    Astronomical events are a sure-fire way to engage students, and this past decade delivered with exciting solar and lunar eclipses that provided real-world lessons about the Sun, the Moon and lunar exploration. The total solar eclipse that crossed the U.S. in 2017 gave students a chance to learn about the dynamic interactions between the Sun and Moon, while brilliant lunar eclipses year after year provided students with lessons in lunar science. There's more to look forward to in the decade ahead as another solar eclipse comes to the U.S. in 2024 – one of nine total solar eclipses around the world in the 2020s. There will be 10 total lunar eclipses in the 2020s, but observing the Moon at any time provides a great opportunity to study celestial patterns and inspire future explorers. Using the lessons below, students can develop and study models to understand the size and scale of the Earth-Moon system, predict future Moon phases and engage in engineering challenges to solve problems that will be faced by future explorers on the Moon!

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    3. Missions to Mars

    Animation of Curiosity driving on Mars

    The past decade showed us the Red Planet in a whole new light. We discovered evidence that suggests Mars could have once supported ancient life, and we developed a better understanding of how the planet lost much of its atmosphere and surface water. The Opportunity rover continued exploring long past its expected lifespan of 90 days as NASA sent a larger, more technologically advanced rover, Curiosity, to take the next steps in understanding the planet's ability to support life. (Opportunity's nearly 15-year mission succumbed to the elements in 2019 after a global dust storm engulfed Mars, blocking the critical sunlight the rover needed to stay powered.) The InSight lander touched down in 2018 to begin exploring interior features of the Red Planet, including marsquakes, while high above, long-lived spacecraft like the Mars Reconnaissance Orbiter and Mars Odyssey were joined by NASA's MAVEN Orbiter, and missions from the European Space Agency and the Indian Space Research Organization. The next decade on Mars will get a kick-start with the July launch of the souped-up Mars 2020 rover, which will look for signs of ancient life and begin collecting samples designed to one day be returned to Earth. Mars provides students with countless opportunities to do some of the same engineering as the folks at NASA and design ideas for future Mars exploration. They can also use Mars as a basis for coding activities, real-world math, and lessons in biology and geology.

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    4. Ocean Worlds and the Search for Life

    Image of Saturn's moon Enceladus covered in ice with giant cracks scarring its surface

    This decade marked the final half of the Cassini spacecraft's 13-year mission at Saturn, during which it made countless discoveries about the planet, its rings and its fascinating moons. Some of the most exciting findings highlighted new frontiers in our search for life beyond Earth. Cassini spotted geysers erupting from cracks in the icy shell of Saturn's moon Enceladus, suggesting the presence of an ocean below. At the moon Titan, the spacecraft peered through the hazy atmosphere to discover an Earth-like hydrologic cycle in which liquid methane and ethane take the place of water. Meanwhile, evidence for another ocean world came to light when the Hubble Space Telescope spotted what appear to be geysers erupting from the icy shell surrounding Jupiter's moon Europa. NASA is currently developing Europa Clipper, a mission that will explore the icy moon of Jupiter to reveal even more about the fascinating world. For students, these discoveries and the moons themselves provide opportunities to build scientific models and improve them as they learn more information. Students can also use math to calculate physical properties of moons throughout the solar system and identify the characteristics that define life as we know it.

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    5. Asteroids, Comets and Dwarf Planets, Oh My!

    Animated image series of comet 67P/Churyumov-Gerasimenko in which the comet tail can be seen shooting out from the comet as it rotates slightly from the perspective of the Rosetta spacecraft

    The past decade was a big deal for small objects in space. NASA's Dawn mission started 2010 as a new arrival in the main asteroid belt. The next eight years saw Dawn explore the two largest objects in the asteroid belt, the giant asteroid Vesta and the dwarf planet Ceres. On its way to comet 67P/Churyumov-Gerasimenko, ESA's Rosetta mission (with contributions from NASA) flew by the asteroid Luticia in 2010. After more than two years at its destination – during which time it measured comet properties, captured breathtaking photos and deposited a lander on the comet – Rosetta's mission ended in dramatic fashion in 2016 when it touched down on 67P/Churyumov-Gerasimenko. In 2013, as scientists around the world eagerly anticipated the near-Earth flyby of asteroid Duende, residents of Chelyabinsk, Russia, got a surprising mid-morning wake-up call when a small, previously undetected asteroid entered the atmosphere, burned as a bright fireball and disintegrated. The team from NASA's OSIRIS-Rex mission wrapped up the decade and set the stage for discoveries in 2020 by selecting the site that the spacecraft will visit in the new year to collect a sample of asteroid Bennu for eventual return to Earth. And in 2022, NASA's Psyche mission will launch for a rendezvous with a type of object never before explored up close: a metal asteroid. The small objects in our solar system present students with chances to explore the composition of comets, use math to calculate properties such as volume, density and kinetic energy of asteroids, and use Newton's Laws in real-world applications, such as spacecraft acceleration.

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    6. Uncovering Pluto's Mysteries

    Image of Pluto in false color from NASA's New Horizons mission

    In 2015, after nearly a decade of travel, NASA's New Horizons spacecraft arrived at Pluto for its planned flyby and became the first spacecraft to visit the dwarf planet and its moons. The images and scientific data the spacecraft returned brought into focus a complex and dynamic world, including seas of ice and mountain ranges. And there's still more left to explore. But New Horizons' journey is far from over. After its flyby of Pluto, the spacecraft continued deep into the Kuiper Belt, the band of icy bodies beyond the orbit of Neptune. In 2019, the spacecraft flew by a snowman-shaped object later named Arrokoth. In the 2020s, New Horizons will continue studying distant Kuiper Belt objects to better understand their physical properties and the region they call home. The new information gathered from the Pluto and Arrokoth flybys provides students with real-life examples of the ways in which scientific understanding changes as additional data is collected and gives them a chance to engage with the data themselves. At the same time, New Horizons' long-distance voyage through the Solar System serves as a good launchpad for discussions of solar system size and scale.

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    7. The Voyagers' Journey Into Interstellar Space

    Animation of Voyager entering interstellar space

    In 1977, two spacecraft left Earth on a journey to explore the outer planets. In the 2010s, decades after their prime mission ended, Voyager 1 and Voyager 2 made history by becoming the first spacecraft to enter interstellar space – the region beyond the influence of solar wind from our Sun. The Voyager spacecraft are expected to continue operating into the 2020s, until their fuel and power run out. In the meantime, they will continue sending data back to Earth, shaping our understanding of the structure of the solar system and interstellar space. The Voyagers can help engage students as they learn about and model the structure of the solar system and use math to understand the challenges of communicating with spacecraft so far away.

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    8. The Search for Planets Beyond Our Solar System

    Illustration of the TRAPPIST-1 star and its system of planets

    It was only a few decades ago that the first planets outside our solar system, or exoplanets, were discovered. The 2010s saw the number of known exoplanets skyrocket in large part thanks to the Kepler mission. A space telescope designed to seek out Earth-sized planets orbiting in the habitable zone – the region around a star where liquid water could exist – Kepler was used to discover more than 2,600 exoplanets. Discoveries from other observatories and amateur astronomers added to the count, now at more than 4,100. In one of the most momentous exoplanet findings of the decade, the Spitzer telescope discovered that the TRAPPIST-1 system, first thought to have three exoplanets, actually had seven – three of which were in the star’s habitable zone. With thousands of candidates discovered by Kepler waiting to be confirmed as exoplanets and NASA's latest space telescope, the Transiting Exoplanet Survey Satellite, or TESS, surveying the entire sky, the 2020s promise to be a decade filled with exoplanet science. And we may not have to wait long for exciting new discoveries from the James Webb Space Telescope, set to launch in 2021. Exoplanets are a great way to get students exploring concepts in science and mathematics. In the lessons linked to below, students use math to find the size and orbital period of planets, learn how scientists are using spectrometry to determine what makes up exoplanet atmospheres and more.

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    9. Shining a Light on Black Holes

    In this historic first image of a black hole, an orange glowing donut-shaped light can be seen against the black backdrop of space. At the center of the light is a black hole.

    Even from millions and billions of light-years away, black holes made big news in the 2010s. First, a collision of two black holes 1.3 billion light-years away sent gravitational waves across the universe that finally reached Earth in 2015, where the waves were detected by the Laser Interferometer Gravitational-Wave Observatory, or LIGO. This was the first detection of gravitational waves in history and confirmed a prediction Einstein made 100 years earlier in his Theory of General Relativity. Then, in 2019, a team of researchers working on the Event Horizon Telescope project announced they had taken the first image capturing the silhouette of a black hole. To take the historic image of the supermassive black hole (named M87* after its location at the center of the M87 galaxy), the team had to create a virtual telescope as large as Earth itself. In addition to capturing the world's attention, the image gave scientists new information about scientific concepts and measurements they had only been able to theorize about in the past. The innovations that led to these discoveries are changing the way scientists can study black holes and how they interact with the space around them. More revelations are likely in the years ahead as scientists continue to analyze the data from these projects. For students, black holes and gravitational waves provide a basis for developing and modifying scientific models. Since they are a topic of immense interest to students, they can also be used to encourage independent research.

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    TAGS: Teachable Moments, K-12 Education, Educators, Students, STEM, Lessons, Activities, Moon, Mars, Ocean Worlds, Small Objects, Pluto, Voyager, Exoplanets, Black Holes, Earth Science, Earth, Climate Change

    • Lyle Tavernier
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    Animated image of Mercury passing in front of the Sun during the 2019 transit of Mercury

    In the News

    It only happens about 13 times a century and won’t happen again until 2032, so don’t miss the transit of Mercury on Monday, Nov. 11! A transit happens when a planet crosses in front of a star. From our perspective on Earth, we only ever see two planets transit the Sun: Mercury and Venus. This is because these are the only planets between us and the Sun. (Transits of Venus are especially rare. The next one won’t happen until 2117.) During the upcoming transit of Mercury, viewers around Earth (using the proper safety equipment) will be able to see a tiny dark spot moving slowly across the disk of the Sun.

    Read on to learn how transits contributed to past scientific discoveries and for a look at how scientists use them today. Plus, find resources for engaging students in this rare celestial event!

    Why It's Important

    Then and Now

    In the early 1600s, Johannes Kepler discovered that both Mercury and Venus would transit the Sun in 1631. It was fortunate timing: The telescope had been invented just 23 years earlier, and the transits of both planets wouldn’t happen in the same year again until 13425. Kepler didn’t survive to see the transits, but French astronomer Pierre Gassendi became the first person to see the transit of Mercury. Poor weather kept other astronomers in Europe from seeing it. (Gassendi attempted to view the transit of Venus the following month, but inaccurate astronomical data led him to mistakenly believe it would be visible from his location.) It was soon understood that transits could be used as an opportunity to measure apparent diameter – how large a planet appears from Earth – with great accuracy.

    After observing the transit of Mercury in 1677, Edmond Halley predicted that transits could be used to accurately measure the distance between the Sun and Earth, which wasn’t known at the time. This could be done by having observers at distant points on Earth look at the variation in a planet’s apparent position against the disk of the Sun – a phenomenon known as parallax shift. This phenomenon is what makes nearby objects appear to shift more than distant objects when you look out the window of a car, for example.

    Today, radar is used to measure the distance between Earth and the Sun with greater precision than transit observations. But the transits of Mercury and Venus still provide scientists with opportunities for scientific investigation in two important areas: exospheres and exoplanets.

    Exosphere Science

    Some objects, like the Moon and Mercury, were originally thought to have no atmosphere. But scientists have discovered that these bodies are actually surrounded by an ultrathin atmosphere of gases called an exosphere. Scientists want to better understand the composition and density of the gases in Mercury’s exosphere, and transits make that possible.

    “When Mercury is in front of the Sun, we can study the exosphere close to the planet,” said NASA scientist Rosemary Killen. “Sodium in the exosphere absorbs and re-emits a yellow-orange color from sunlight, and by measuring that absorption, we can learn about the density of gas there.”

    Exoplanet Discoveries

    When Mercury transits the Sun, it causes a slight dip in the Sun’s brightness as it blocks a tiny portion of the Sun’s light. Scientists discovered they could use that phenomenon to search for planets orbiting distant stars. These planets, called exoplanets, are otherwise obscured from view by the light of their star. When measuring the brightness of far-off stars, a slight recurring dip in the light curve (a graph of light intensity) could indicate an exoplanet orbiting and transiting its star. NASA’s Kepler space telescope found more than 2,700 exoplanets by looking for this telltale drop in brightness. NASA’s TESS mission is surveying 200,000 of the brightest stars near our solar system and is expected to potentially discover more than 10,000 transiting exoplanets.

    Animated cartoon image of a planet crossing in front of a star and an inset that shows a graph dipping as the planet does so

    This animation shows one method scientists use to hunt for planets outside our solar system. When exoplanets transit their parent star, we can detect the dip in the star’s brightness using space telescopes. Credit: NASA/JPL-Caltech | + Expand image

    Additionally, scientists have been exploring the atmospheres of exoplanets. Similarly to how we study Mercury’s exosphere, scientists can observe the spectra – a measure of light intensity and wavelength – that passes through an exoplanet’s atmosphere. As a result, they’re beginning to understand the evolution and composition of exoplanet atmospheres, as well as the influence of stellar wind and magnetic fields.

    Collage of exoplanet posters from NASA

    Using the transit method and other techniques, scientists are learning more and more about planets beyond our solar system. These discoveries have even inspired a series of posters created by artists at NASA, who imagine what future explorers might encounter on these faraway worlds. Credit: NASA | › Download posters

    Watch It

    During the transit of Mercury, the planet will appear as a tiny dot on the Sun’s surface. To see it, you’ll need a telescope or binoculars outfitted with a special solar filter.

    WARNING! Looking at the Sun directly or through a telescope without proper protection can lead to serious and permanent vision damage. Do not look directly at the Sun without a certified solar filter.

    The transit of Mercury will be partly or fully visible across much of the globe. However, it won’t be visible from Australia or most of Asia and Alaska.

    Graphic showing Mercury's path across the Sun on Nov. 11, 2019 and the times that it will be at each location

    The transit of Mercury on Nov. 11, 2019, begins at 4:35 a.m. PST (7:35 a.m. EST), but it won’t be visible to West Coast viewers until after sunrise. Luckily, viewers will have several more hours to take in the stellar show, which lasts until 10:04 a.m. PST (1:04 p.m. EST). Credit: NASA/JPL-Caltech | + Expand image

    Mercury’s trek across the Sun begins at 4:35 a.m. PST (7:35 a.m. EST), meaning viewers on the East Coast of the U.S. can experience the entire event, as the Sun will have already risen before the transit begins. By the time the Sun rises on the West Coast, Mercury will have been transiting the Sun for nearly two hours. Fortunately, the planet will take almost 5.5 hours to completely cross the face of the Sun, so there will be plenty of time for West Coast viewers to witness this event. See the transit map below to learn when and where the transit will be visible.

    Graphic showing a flat map of the world with areas where the transit of Mercury on Nov. 11, 2019 will be partially to fully visible indicated along with transit start and end times

    This map shows where and when the transit will be visible on November 11. Image credit: NASA/JPL-Caltech | + Expand image

    Don’t have access to a telescope or binoculars with a solar filter? Visit the Night Sky Network website to find events near you where amateur astronomers will have viewing opportunities available.

    During the transit, NASA will share near-real-time images of the Sun directly from the Solar Dynamics Observatory. Beginning at 4:41 a.m. PST (7:41 a.m. EST) you can see images of Mercury passing in front of the Sun at NASA’s 2019 Mercury Transit page, with updates through the end of the transit at 10:04 a.m. PST (1:04 p.m. EST).

    If you’re in the U.S., don’t miss the show, as this is the last time a transit will be visible from the continental United States until 2049!

    Watch this month's installment of "What's Up" to learn more about how to watch the Nov. 11 transit of Mercury. Credit: NASA/JPL-Caltech | Watch on YouTube

    Teach It

    Use these lessons and activities to engage students in the transit of Mercury and the hunt for planets beyond our solar system:

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    Transit Resources:

    Exoplanet Resources:

    Check out these related resources for kids from NASA’s Space Place:

    TAGS: K-12 Education, Teachers, Students, Educators, Mercury, Transit, Transit of Mercury, What's Up, Astronomy, Resources for Educators, Exoplanets, Kepler, TESS

    • Lyle Tavernier
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