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Animation showing a total lunar eclipse. Credit: NASA Goddard Media Studios

There’s no better time to learn about the Moon than during a lunar eclipse. Here’s how to get students watching and exploring more.

This article has been updated to include information about the visibility and timing of the total lunar eclipse on May 26, 2021. See the "What to Expect" section below for details.


A full moon is always a good reason to go outside and look up, but a total or partial lunar eclipse is an awe-inspiring sight that gives students a great opportunity to engage in practical sky watching. Whether it’s the Moon's reddish hue during a total lunar eclipse or the "bite" taken out of the Moon during a partial lunar eclipse, there's always something exciting to observe during these celestial events. Read on to see what to expect during the next lunar eclipse. Plus, explore resources you can use at home or in the classroom to teach students about moon phases, craters, and more!

How It Works

Side-by-side images showing how the Moon, Sun and Earth align during an lunar eclipse versus a standard full moon

These side-by-side graphics show how the Moon, Sun, and Earth align during a lunar eclipse (left) versus a non-eclipse full moon (right). Credit: NASA Goddard Visualization Studio | + Enlarge image

Eclipses can occur when the Sun, the Moon, and Earth align. Lunar eclipses can only happen during the full moon phase, when the Moon and the Sun are on opposite sides of Earth. At that point, the Moon could move into the shadow cast by Earth, resulting in a lunar eclipse. However, most of the time, the Moon’s slightly tilted orbit brings it above or below the shadow of Earth.

The time period when the Moon, Earth, and the Sun are lined up and on the same plane – allowing for the Moon to pass through Earth’s shadow – is called an eclipse season. Eclipse seasons last about 34 days and occur just shy of every six months. When a full moon occurs during an eclipse season, the Moon travels through Earth’s shadow, creating a lunar eclipse.

Graphic showing the alignment of the Sun, Earth and Moon when a full moon occurs during an eclipse season versus a non-eclipse season

When a full moon occurs during an eclipse season, the Moon travels through Earth's shadow, creating a lunar eclipse. Credit: NASA/JPL-Caltech | + Enlarge image

Unlike solar eclipses, which require special glasses to view and can only be seen for a few short minutes in a very limited area, a total lunar eclipse can be seen for up to an hour by anyone on the nighttime side of Earth – as long as skies are clear!

Why It’s Important

Lunar eclipses have long played an important role in understanding Earth and its motions in space.

In ancient Greece, Aristotle noted that the shadows on the Moon during lunar eclipses were round, regardless of where an observer saw them. He realized that only if Earth were a spheroid would its shadows be round – a revelation that he and others had many centuries before the first ships sailed around the world.

Earth wobbles on its axis like a spinning top that’s about to fall over, a phenomenon called precession. Earth completes one wobble, or precession cycle, over the course of 26,000 years. Greek astronomer Hipparchus made this discovery by comparing the position of stars relative to the Sun during a lunar eclipse to those recorded hundreds of years earlier. A lunar eclipse allowed him to see the stars and know exactly where the Sun was for comparison – directly opposite the Moon. If Earth didn’t wobble, the stars would appear to be in the same place they were hundreds of years earlier. When Hipparchus saw that the stars’ positions had indeed moved, he knew that Earth must wobble on its axis!

Additionally, modern-day astronomers have used ancient eclipse records and compared them with computer simulations. These comparisons helped scientists determine the rate at which Earth’s rotation is slowing.

What to Expect

Graphic showing the positions of the Moon, Earth and Sun during a partial lunar eclipse

During a total lunar eclipse, the Moon first enters into the penumbra, or the outer part of Earth's shadow, where the shadow is still penetrated by some sunlight. Credit: NASA | + Enlarge image

The Moon as seen during a partial lunar eclipse

As the Moon starts to enter into the umbra, the inner and darker part of Earth's shadow, it appears as if a bite has been taken out of the Moon. This "bite" will grow until the Moon has entered fully into the umbra. Credit: NASA | + Enlarge image

Graphic showing the Moon inside the umbra

The total lunar eclipse starts once the moon is completely inside the umbra. And the moment of greatest eclipse happens with the Moon is halfway through the umbra as shown in this graphic. Credit: NASA | + Enlarge image

The Moon as seen during a total lunar eclipse at the point of greatest eclipse

As the Moon moves completely into the umbra, it turns a reddish-orange color. Credit: NASA | + Enlarge image

The Moon passes through two distinct parts of Earth’s shadow during a lunar eclipse. The outer part of the cone-shaped shadow is called the penumbra. The penumbra is less dark than the inner part of the shadow because it’s penetrated by some sunlight. (You have probably noticed that some shadows on the ground are darker than others, depending on how much outside light enters the shadow; the same is true for the outer part of Earth’s shadow). The inner part of the shadow, known as the umbra, is much darker because Earth blocks additional sunlight from entering the umbra.

Here's what to expect during the total lunar eclipse on May 26, 2021, which will be visible in western North and South America, as well as in eastern Asia, Australia, and the Pacific Ocean. Note: Viewers in the Midwest and the eastern U.S. can still look up to see a partial eclipse grace the sky.

At 1:47 a.m. PDT, the edge of the Moon will begin entering the penumbra. The Moon will dim very slightly for the next 57 minutes as it moves deeper into the penumbra. Because this part of Earth’s shadow is not fully dark, you may only notice some dim shading (if anything at all) on the Moon near the end of this part of the eclipse. Should you decide to sleep in during this time, you won’t miss much.

At 2:45 a.m. PDT, the edge of the Moon will begin entering the umbra. As the Moon moves into the darker shadow, significant darkening will be noticeable. Some say that during this part of the eclipse, the Moon looks as if it has had a bite taken out of it. That “bite” gets bigger and bigger as the Moon moves deeper into the shadow. During this part, viewers in most of the eastern U.S. will see the Moon as it moves into the umbra but lose visibility once the Moon dips below the horizon and the Sun rises.

At 4:11 a.m. PDT, the Moon will be completely inside the umbra, marking the beginning of the total lunar eclipse. The moment of greatest eclipse, when the Moon is halfway through its path across the umbra, occurs at 4:19 a.m. PDT.

As the Moon moves completely into the umbra, something interesting happens: The Moon begins to turn reddish-orange. The reason for this phenomenon? Earth’s atmosphere. As sunlight passes through it, the small molecules that make up our atmosphere scatter blue light, which is why the sky appears blue. This leaves behind mostly red light that bends, or refracts, into Earth’s shadow. We can see the red light during an eclipse as it falls onto the Moon in Earth’s shadow. This same effect is what gives sunrises and sunsets a reddish-orange color.

A variety of factors affect the appearance of the Moon during a total lunar eclipse. Clouds, dust, ash, photochemical droplets, and organic material in the atmosphere can change how much light is refracted into the umbra. Additionally, the May 2021 lunar eclipse takes place when the full moon is at or near the closest point in its orbit to Earth (popularly known as a supermoon). This means it is deeper inside the umbra shadow and therefore may appear darker. The potential for variation provides a great opportunity for students to observe and classify the lunar eclipse based on its brightness. Details can be found below in the “Teach It” section.

At 4:25 a.m. PDT, the edge of the Moon will begin exiting the umbra and moving into the opposite side of the penumbra. This marks the end of the total lunar eclipse.

At 5:52 a.m. PDT, the Moon will be completely outside of the umbra and will begin exiting the penumbra until the eclipse ends at 6:49 a.m. PDT.

Teach It

Ask students to observe the lunar eclipse and evaluate the Moon’s brightness using the Danjon Scale of Lunar Eclipse Brightness. The Danjon scale illustrates the range of colors and brightness the Moon can take on during a total lunar eclipse and is a tool observers can use to characterize the appearance of an eclipse. View the lesson guide here. After the eclipse, have students compare and justify their evaluations of the eclipse.

Use these standards-aligned lessons and related activities to get your students excited about the eclipse, moon phases, and Moon observations.

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TAGS: Lunar Eclipse, Moon, Super Blue Blood Moon, Observe the Moon, Eclipse, K-12, Classroom Activities, Teaching

  • Lyle Tavernier
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The Millennium Falcon takes on TIE fighters in a scene from 'Star Wars: The Force Awakens.'

Science fiction meets science fact in this Star Wars inspired Teachable Moment all about ion propulsion and Newton’s Laws.

In the News

What do "Star Wars," NASA's Dawn spacecraft and Newton's Laws of Motion have in common? An educational lesson that turns science fiction into science fact using spreadsheets – a powerful tool for developing the scientific models addressed in the Next Generation Science Standards. Keep reading to learn more and find out how to get students weilding the force.

Why It's Important

The TIE (Twin Ion Engine) fighter is a staple of the "Star Wars" universe. Darth Vader flew one in "A New Hope." Poe Dameron piloted one in "The Force Awakens." And many, many Imperial pilots met their fates in them. While the fictional TIE fighters in "Star Wars" flew a long time ago in a galaxy far, far away, ion engines are a reality in this galaxy today – and have a unique connection to NASA’s Jet Propulsion Laboratory.

Launched in 1998, the first spacecraft to use an ion engine was Deep Space 1, which flew by asteroid 9969 Braille and comet Borrelly. Fueled by the success of Deep Space 1, engineers at JPL set forth to develop the next spacecraft that would use ion propulsion. This mission, called Dawn, would take ion-powered spacecraft to the next level by allowing Dawn to go into orbit twice – around the two largest objects in the asteroid belt: Vesta and Ceres.

How It Works

Ion engines rely on two principles that Isaac Newton first described in 1687. First, a positively charged atom (ion) is pushed out of the engine at a high velocity. Newton’s Third Law of Motion states that for every action there is an equal and opposite reaction, so then a small force pushes back on the spacecraft in the opposite direction – forward! According to Newton’s Second Law of Motion, there is a relationship between the force (F) exerted on an object, its mass (m) and its acceleration (a). The equation F=ma describes that relationship and tells us that the small force applied to the spacecraft by the exiting atom provides a small amount of acceleration to the spacecraft. Push enough atoms out, and you'll get enough acceleration to really speed things up.


Why is It Important?

Compared with traditional chemical rockets, ion propulsion is faster, cheaper and safer:

  • Faster: Spacecraft powered by ion engines can reach speeds of up to 90,000 meters per second (more than 201,000 mph!)
  • Cheaper: When it comes to fuel efficiency, ion engines can reach more than 90 percent fuel efficiency, while chemical rockets are only about 35 percent efficient.
  • Safer: Ion thrusters are fueled by inert gases. Most of them use xenon, which is a non-toxic, chemically inert (no risk of exploding), odorless, tasteless and colorless gas.

These properties make ion propulsion a very attractive solution when engineers are designing spacecraft. While not every spacecraft can use ion propulsion – some need greater rates of acceleration than ion propulsion can provide – the number and types of missions using these efficient engines is growing. In addition to being used on the Dawn spacecraft and communication satellites orbiting Earth, ion propulsion could be used to boost the International Space Station into higher orbits and will likely be a part of many future missions exploring our own solar system.

Teach It

Newton’s Laws of Motion are an important part of middle and high school physical science and are addressed specifically by the Next Generation Science Standards as well as Common Core Math standards. The lesson "Ion Propulsion: Using Spreadsheets to Model Additive Velocity" lets students study the relationship between force, mass and acceleration as described by Newton's Second Law as they develop spreadsheet models that apply those principles to real-world situations.

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This feature was originally published on May 3, 2016.

TAGS: May the Fourth, Star Wars Day, F=ma, ion propulsion, Dawn, Deep Space 1, lesson, classroom activity, NGSS, Common Core Math

  • Lyle Tavernier
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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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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 touched 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

Perseverance 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, listening to expert talks, and sharing student work with a worldwide audience. 

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:

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    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

    Explore More


    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

    Blogs and Features

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    NOAA Video Series: Coral Comeback

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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:


    Explore More

    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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