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Teachable Moments | December 8, 2022

NASA Mission Takes a Deep Dive Into Earth's Surface Water

By Ota Lutz

A rectangular box-shaped spacecraft with long arms extending from either side. Above the arms are wing-like solar panels extending in the opposite direction. The curvature of Earth and wispy clouds are depicted just below the spacecraft.

Explore how and why the SWOT mission will take stock of Earth's water budget, what it could mean for assessing climate change, and how to bring it all to students.

Update: Dec. 15, 2022 – NASA, the French space agency, and SpaceX are now targeting 3:46 a.m. PST (6:46 a.m. EST) on Friday, Dec.16, for the launch of the Surface Water and Ocean Topography (SWOT) satellite. Visit NASA's SWOT launch blog for the latest updates.

NASA is launching an Earth-orbiting mission that will map the planet’s surface water resources better than ever before. Scheduled to launch on Dec. 16 from Vandenberg Space Force Base in California, the Surface Water and Ocean Topography, or SWOT mission is the latest international collaboration designed to monitor and report on our home planet. By providing us with a highly detailed 3D view of rivers, lakes, and oceans, SWOT promises to improve our understanding of Earth’s water cycle and the role oceans play in climate change, as well as help us better respond to drought and flooding.

Read on to find out why we're hoping to learn more about Earth's surface water, get to know the science behind SWOT's unique design, and follow along with STEM teaching and learning resources.

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Why It's Important

Observing Earth from space provides scientists with a global view that is important for understanding the whole climate system. In the case of SWOT, we will be able to monitor Earth’s surface water with unprecedented detail and accuracy. SWOT will provide scientists with measurements of water volume change and movement that will inform our understanding of fresh water availability, flood hazards, and the mechanisms of climate change.

Scientists and engineers provide an overview of the SWOT mission. Credit: NASA/JPL-Caltech | Watch on YouTube

Water Flow

Scientists use a variety of methods to track Earth’s water. These include stream and lake gauges and even measurements from space such as sea surface altimetry and gravitational measurements of aquifer volumes. Monitoring of river flow and lake volume is important because it can tell us how much freshwater is readily available and at what locations. River flow monitoring can also help us make inferences about the downstream environmental impact. But monitoring Earth’s surface water in great detail with enough frequency to track water movement has proven challenging. Until now, most monitoring of river flow and lake levels has relied on water-flow and water-level gauges placed across Earth, which requires that they be accessible and maintained. Not all streams and lakes have gauges and previous space-based altimetry and gravitational measurements, though useful for large bodies of water, have not been able to adequately track the constant movement of water through smaller rivers or lakes.

Here's why understanding Earth’s "water budget" is an important part of understanding our planet and planning for future water needs.

SWOT will be able to capture these measurements across the globe in 3D every 21 days. The mission will monitor how much water is flowing through hundreds of thousands of rivers wider than 330 feet (100 meters) and keep a close watch on the levels of more than a million lakes larger than 15 acres (6 hectares). Data from the mission will be used to create detailed maps of rivers, lakes, and reservoirs that will enable accurate monitoring to provide a view of freshwater resources that is not reliant on physical access. Meanwhile, SWOT’s volumetric measurements of rivers, lakes, and reservoirs will help hydrologists better track drought and flooding impacts in near-real-time.

Coastal Sea Level Rise

SWOT will measure our oceans with unprecedented accuracy, revealing details of ocean features as small as 9 miles (15 kilometers) across. SWOT will also monitor sea levels and tides. Though we have excellent global sea level data, we do not have detailed sea level measurements near coastlines. Coastal sea levels vary across the globe as a result of ocean currents, weather patterns, land changes, and other factors. Sea levels are rising faster than ever, and higher sea levels also mean that hurricane storm surges will reach farther inland than ever before, causing substantially more damage than the same category of hurricanes in the past. SWOT will be able to monitor coastal sea level variations and fill gaps in the observations we currently have from other sources.

What is sea level rise and what does it mean for our planet? | › View Transcript

Ocean Heat Sinks

Further contributing to our understanding of the role Earth’s oceans play in climate change, SWOT will explore how the ocean absorbs atmospheric heat and carbon, moderating global temperatures and climate change. Scientists understand ocean circulation on a large scale and know that ocean currents are driven by temperature and salinity differences. However, scientists do not currently have a good understanding of fine-scale ocean currents, where most of the ocean's motion-related energy is stored and lost. Circulation at these fine scales is thought to be responsible for transporting half of the heat and carbon from the upper ocean to deeper layers. Such downward ocean currents have helped to mitigate the decades-long rise in global air temperatures by absorbing and storing heat and carbon away from the atmosphere. Knowing more about this process is critical for understanding the mechanisms of global climate change.

JPL scientist Josh Willis uses a water balloon to show how Earth's oceans are absorbing most of the heat being trapped on our warming world. | › Related lesson

These fine-scale ocean currents also transport nutrients to marine life and circulate pollutants such as crude oil and debris. Understanding nutrient transport helps oceanographers assess ocean health and the productivity of fisheries. And tracking pollutants aids in natural hazard assessment, prediction, and response.

How It Works

A joint effort between NASA and the French space agency – with contributions from the Canadian and UK space agencies – SWOT will continue NASA’s decades-long record of monitoring sea surface height across the globe. But this mission will add a level of detail never before achieved.

SWOT will measure more than 90% of Earth’s surface water, scanning the planet between 78°N latitude and 78°S latitude within 1 centimeter of accuracy and retracing the same path every 21 days. Achieving this level of accuracy from a spacecraft height of 554 miles (891 kilometers) requires that the boom using radar to measure water elevation remain stable within 2 microns – or about 3% of the thickness of a human hair.

This visualization shows ocean surface currents around the world during the period from June 2005 through December 2007. With its new, high resolution wide-swath measurements, SWOT will be able to observe eddies and current features at greater resolution than previously possible. Credit: NASA Scientific Visualization Studio | Watch on YouTube

Prior to SWOT, spacecraft have used conventional nadir, or straight-down, altimetry to measure sea surface height. Conventional nadir altimetry sends a series of radar or laser pulses down to the surface and measures the time it takes for each signal to return to the spacecraft, thus revealing distances to surface features. To acquire more detailed information on surface water, SWOT will use an innovative instrument called the Ka-band Radar Interferometer, or KaRIn, to measure water height with exceptional accuracy. Ka-band is a portion of the microwave part of the electromagnetic spectrum. SWOT uses microwaves because they can penetrate clouds to return data about water surfaces.

A radar signal is sent straight down from the SWOT spacecraft as it flies over Earth. Beams are shown bouncing back to receivers on either side of the spacecraft. The section of Earth measured by the spacecraft is shown as two side-by-side tracks colored in as a heatmap. The camera zooms out to show these tracks criscrossing the planet and eventually covering a majority of the surface.

SWOT will track Earth's surface water in incredible detail using an innovative instrument called the Ka-band Radar Interferometer, or KaRIn. Image credit: NASA/JPL-Caltech | + Expand image

The KaRIn instrument uses the principles of synthetic aperture radar combined with interferometry to measure sea surface height. A radar signal is emitted from the end of the 10-meter-wide boom on the spacecraft. The reflected signal is then received by antennas on both ends of the boom, capturing data from two 30-mile (50-kilometer) wide swaths on either side of the spacecraft. The received signals will be slightly out of sync, or phase, from one another because they will travel different distances to return to the receivers on either end of the boom. Knowing the phase difference, the distance between the antennas, and the radar wavelength allows us to calculate the distance to the surface.

The first of three images shows two paths of different lengths extending diagonally from a point on Earth’s surface to receivers on either side of the SWOT spacecraft. A second image shows the paths as light waves that are slightly out of phase. The third image shows a line drawn directly from the rightmost receiver to the path leading to the leftmost receiver, such that the intersected paths from Earth are equal in length. The upper triangle formed by this intersection has a short leg, highlighted in yellow, that represents the remaining length of the leftmost path. The yellow short leg represents the range difference between the two paths from Earth.

Radar signals bounced off the water’s surface will be received by antennas on both ends of SWOT's 10-meter-wide boom. The received signals will be slightly out of phase because they will travel different distances as they return to the receivers. Scientists use this phase difference and the radar wavelength to calculate the distance to the surface. Image credit: NASA/JPL-Caltech | + Expand image

The observations acquired by the two antennas can be combined into what is known as an interferogram. An interferogram is a pattern of wave interference that can reveal more detail beyond the 1-centimeter resolution captured by the radar. To explain how it works, we'll recall a couple of concepts from high school physics. When out-of-phase waves from the two antennas are combined, constructive and destructive interference patterns result in some wave crests being higher and some wave troughs being lower than those of the original waves. The patterns that result from the combination of the waves reveal more detail with resolution better than the 1-centimeter wavelength of the original Ka-band radar waves because the interference occurs over a portion of a wavelength. An interferogram can be coupled with elevation data to reveal a 3D representation of the water’s surface.

A diagram illustrating the swaths of data that SWOT will collect, including labels for the following: 10 m baseline between SWOT's receivers; a distance of 891 km between the surface and Interferometer Antenna 1; Interferometer Left Swath resulting in ocean topography with an H-Pol swath of 10-60 km; Interferometer Right Swath resulting in surface water topography with a V-Pol of 10-60 km; a straight-down Nadir Altimeter path directly below the spacecraft in the gap between the swaths; a cross-track resolution from 70m to 10m.

The KaRIn instrument illuminates two parallel tracks of approximately 50 kilometres on either side of a nadir track from a traditional altimeter. The signals are received by two antennas 10 metres apart and are then processed to yield interferometry measurements. Image credit: NASA/JPL-Caltech | + Expand image

This highly accurate 3D view of Earth’s surface water is what makes SWOT so unique and will enable scientists to more closely monitor the dynamics of the water cycle. In addition to observing ocean currents and eddies that will inform our understanding of the ocean’s role in climate change, SWOT's use of interferometry will allow scientists to track volumetric changes in lakes and quantify river flooding, tasks that cannot yet be done on a wide scale in any other way.

A colorful swath of yellows, oranges, magentas, purples is overlaid horizontally on a satellite image of desert landscape with thin yellow and red lines cutting diagonally across the image. On the center-left of the image, the colors fan out like a rainbow sprinkler. On the left side of the swath are a cluster of yellow dots.

This interferogram was captured by the air-based UAVSAR instrument of the magnitude 7.2 Baja California earthquake of April 4, 2010. The interferogram is overlaid atop a Google Earth image of the region. Image credit: NASA/JPL/USGS/Google | › Learn more

Follow Along

SWOT is scheduled to launch no earlier than Dec. 16, 2022, on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California. Tune in to watch the launch on NASA TV.

After launch, the spacecraft will spend 6-months in a calibration and validation phase, during which it will make a full orbit of Earth every day at an altitude of 553 miles (857 kilometers). Upon completion of this phase, SWOT will increase its altitude to 554 miles (891 kilometers) and assume a 21-day repeat orbit for the remainder of its mission.

Visit the mission website to follow along as data are returned and explore the latest news, images, and updates as SWOT provides a new view on one of our planet's most important resources.

Teach It

The SWOT mission is the perfect opportunity to engage students in studying Earth’s water budget and water cycle. Explore these lessons and resources to get students excited about the STEM involved in studying Earth’s water and climate change from space.

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TAGS: K-12 Education, Teachers, Educators, Earth Science, Earth, Climate Change, Climate, Satellites, Teachable Moments

  • Ota Lutz
    ABOUT THE AUTHOR

    Ota Lutz, K-12 Education Group Manager, NASA-JPL Education Office

    Ota Lutz is the manager of the K-12 Education Group at NASA’s Jet Propulsion Laboratory. When she’s not writing new lessons or teaching, she’s probably cooking something delicious, volunteering in the community, or dreaming about where she will travel next.

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Edu News | August 24, 2022

A Lesson for Every Day of the School Year

By Kim Orr

Collage of images from the events and lessons featured in this article.

With 180 lessons in our online catalog, you can explore Earth and space with us all year long. We show you how with this handy NASA-JPL school year calendar.

We just added the 180th lesson to our online catalog of standards-aligned STEM lessons, which means JPL Education now has a lesson for every day of the school year. To celebrate and help you make the year ahead stellar, we've put together this monthly calendar of upcoming NASA events along with links to our related lessons, Teachable Moments articles, and student projects you can use to engage students in STEM while they explore Earth and space with us all year long.

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August

The Voyagers Turn 45

The twin Voyager spacecraft launched in 1977 on a journey to explore the outer planets and beyond – and they're still going. Now more than 12 billion miles (19 billion kilometers) from Earth in a region known as interstellar space, they're the most distant human-made objects in space.

Get a primer on these fascinating spacecraft from Teachable Moments, then use it as a jumping off point for lessons on the scale, size, and structure of our solar system and how we communicate with distant spacecraft.

Lessons & Resources:

September

Rendezvous with an Asteroid

A distant asteroid system 6.8 million miles (11 million kilometers) from Earth was the site of NASA's first attempt at redirecting an asteroid. On September 26, the Double Asteroid Redirection Test, or DART, mission impacted the asteroid Dimorphos in an attempt to alter its speed and path around a larger asteroid known as Didymos. Dimorphos and Didymos do not pose a threat to Earth, which makes them a good proving ground for testing whether a similar technique could be used to defend Earth against potential impacts by hazardous asteroids in the future.

Get a primer on the DART mission and find related resources for the classroom in this article from our Teachable Moments series. Plus, explore our collection of standards-aligned lessons and activities all about asteroids to get students learning about different kinds of space rocks, geology, and meteoroid math.

Lessons & Resources:

A Closer Look at Europa

Just a few days later, on September 29, the Juno spacecraft that had been orbiting Jupiter since 2016 captured the closest views of Jupiter’s moon Europa in more than 20 years. The ice-covered moon is thought to contain a subsurface liquid-water ocean, making it an exciting new frontier in our search for life beyond Earth. NASA's Europa Clipper mission, which is scheduled to launch in 2024 is designed to study the moon in more detail. But until Europa Clipper arrives at the Jovian system in 2030, these observations from Juno are our best chance to get a closer look at this fascinating moon.

Learn more about Europa and why it is interesting to scientists in this talk from our Teaching Space With NASA series featuring a Europa Clipper mission scientist. Then, explore our Ocean Worlds Lesson Collection for ideas on making classroom connections.

Lessons & Resources:

October

Celebrate Halloween Like a Space Explorer

The month of October is the perfect time to get students exploring our STEM activities with a Halloween twist. Students can learn how to carve a pumpkin like a JPL engineer, take a tour of mysterious locations throughout the solar system, and dig into the geology inside their Halloween candy.

October 31 is also JPL's 86th birthday, which makes October a great time to learn more about JPL history, including the team of female mathematicians known as "human computers" who performed some of the earliest spacecraft-tracking calculations and the Laboratory's role in launching the first U.S. space satellite.

Lessons & Resources:

November

Watch a Total Lunar Eclipse

Look up in the early morning hours of November 8 to watch one of the most stunning spectacles visible from Earth: a total lunar eclipse. This one will be viewable in North and South America, as well as Asia and Australia.

Learn more about lunar eclipses and how to watch them from our Teachable Moments series. Then, get students of all ages outside and observing the Moon with lessons on moon phases and the hows and whys of eclipses. Students can even build a Moon calendar so they always know when and where to look for the next eclipse.

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Artemis Takes a Giant Leap

NASA is making plans to send astronauts back to the Moon for the first time since 1972 – this time to establish a sustainable presence and prepare for future human missions to Mars. The first major step is Artemis I, which is testing three key components required to send astronauts beyond the Moon: the Orion spacecraft, the Space Launch System, or SLS, rocket and the ground systems at Kennedy Space Center in Florida. The uncrewed Artemis I mission marks the first test of all three components at once.

Get your K-12 students following along with lessons in rocketry and what it takes to live in space. Plus, register to follow along with the mission with resources and updates from NASA's Office of STEM Engagement.

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December

Satellite Launches on a Mission to Follow the Water

As crucial as water is to human life, did you know that no one has ever completed a global survey of Earth’s surface water? That is about to change with the launch of the SWOT mission. SWOT, which stands for Surface Water Ocean Topography, will use a state-of-the-art radar to measure the elevation of water in major lakes, rivers, wetlands, and reservoirs. It will also provide an unprecedented level of detail on the ocean surface. This data will help scientists track how these bodies of water are changing over time and improve weather and climate models.

Engage your students in learning about Earth’s water budget and how we monitor Earth from space with these lessons. And be sure to check out our Teachable Moments article for more about the SWOT mission and the science of our changing climate.

Prepare for the Science Fair

Before you know it, it'll be science fair time. Avoid the stress of science fair prep by getting students organized and thinking about their projects before the winter recess. Start by watching our video series How to Do a Science Fair Project. A scientist and an engineer from JPL walk your students through all the steps they will need to create an original science fair project by observing the world around them and asking questions. You can also explore our science fair starter pack of lessons and projects to get students generating ideas and thinking like scientists and engineers.

Lessons & Resources:

January

Explore STEM Careers

January is the time when many of us set goals for the year ahead, so it's the perfect month to get students exploring their career goals and opportunities in STEM. Students can learn more about careers in STEM and hear directly from scientists and engineers working on NASA missions in our Teaching Space video series. Meanwhile, our news page has more on what it takes to be a NASA astronaut and what it's like to be a JPL intern.

For students already in college and pursuing STEM degrees, now is the time to start exploring internship opportunities for the summer. The deadline for JPL summer internships is in March, so it's a good idea to refresh your resume and get your application started now. Learn how to stand out with this article on how to get an internship at JPL – which also includes advice for pre-college students.

Resources:

February

Mars Rover Celebrates 2-Year 'Landiversary'

NASA's Perseverance Mars rover celebrates its "landiversary" on February 18, which marks two years since the rover made its nail-biting descent on the Red Planet. The rover continues to explore Jezero Crater using science tools to analyze rocks and soil in search of signs of ancient microbial life. As of this writing, the rover has collected twelve rock core samples that will be sent to Earth by a future mission. Perseverance even witnessed a solar eclipse! Meanwhile, the Ingenuity Mars helicopter, which the rover deployed shortly after landing, has gone on to achieve feats of its own.

The Mission to Mars Student Challenge is a great way to get students of all ages exploring STEM and the Red Planet right along with the Perseverance rover. The challenge includes seven weeks of education content that can be customized for your classroom as well as education plans, expert talks, and resources from NASA.

Lessons & Resources:

March

Take On the Pi Day Challenge

Math teachers, pie-lovers, and pun-aficionados rejoice! March 14 is Pi Day, the annual celebration of the mathematical constant used throughout the STEM world – and especially for space exploration. This year's celebration brings the 10th installment of the NASA Pi Day Challenge, featuring four new illustrated math problems involving pi along with NASA missions and science.

Explore the full collection of pi math lessons, get students learning about how we use pi at NASA, and hear from a JPL engineer on how many decimals of pi we use for space exploration at the links below.

Lessons & Resources:

April

Celebrate Earth Day With NASA

You may not immediately think of Earth science when you think of NASA, but it's a big part of what we do. Earth Day on April 22 is a great time to explore Earth science with NASA, especially as new missions are taking to the skies to study the movements of dust, measure surface water across the planet, and track tiny land movements to better predict natural disasters.

Whether you want to focus on Earth’s surface and geology, climate change, extreme weather, or the water budget, we have an abundance of lessons, student projects and Teachable Moments to guide your way.

Lessons & Resources:

May

Summer Learning Adventures

As the school year comes to a close, send your students off on an adventure of summer learning with our do-it-yourself STEM projects. Additionally, our Learning Space With NASA at Home page and video series is a great resource for parents and families to help direct students' learning during out-of-school time.

Lessons & Resources:

TAGS: K-12 Education, Teachers, Students, Lessons, Resources, Projects, Events, Artemis, Voyager, DART, Asteroids, Europa, Ocean Worlds, Halloween, History, Earth, Climate, SWOT, Lunar Eclipse, Science Fair, Career Advice, Mars, Perseverance, Pi Day, Earth Day, Summer STEM

  • Kim Orr
    ABOUT THE AUTHOR

    Kim Orr, Web Producer, NASA-JPL Education Office

    Kim Orr is a web and content producer for the Education Office at NASA's Jet Propulsion Laboratory. Her pastimes are laughing and going on Indiana Jones style adventures.

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Teachable Moments | May 2, 2022

How NASA Plans to Dig Up the Dirt on Climate Change

By Brandon Rodriguez

A small piece of the ISS is visible in the top corner of this view looking down from space station over Earth. A large cloud of dust takes half the view over Earth's surface.

A data map overlaid on the globe shows thick swirls of dust traveling from West Africa, across the Atlantic Ocean and all the way to the Caribbean and Southern U.S.

Learn about the role that dust plays in Earth's climate, why scientists are interested in studying dust from space, and how to engage students in the science with STEM resources from JPL.

A NASA instrument launched to the International Space Station this summer will explore how dust impacts global temperatures, cloud formation, and the health of our oceans. The Earth Surface Mineral Dust Source Investigation, or EMIT, is the first instrument of its kind, designed to collect measurements from space of some of the most arid regions on Earth to understand the composition of soils that generate dust and the larger role dust plays in climate change.

Read on to find out how the instrument works and why scientists are hoping to learn more about the composition of dust. Then, explore how to bring the science into your classroom with related climate lessons that bridge physical sciences with engineering practices.

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Why It’s Important

Scientists have long studied the movements of dust. The fact that dust storms can carry tiny particles great distances was reported in the scientific literature nearly two centuries ago by none other than Charles Darwin as he sailed across the Atlantic on the HMS Beagle. What still remains a mystery all these years later is what that dust is made of, how it moves, and how that affects the health of our planet.

For example, we now know that dust deposited on snow speeds up snow melt even more than increased air temperature. That is to say, that dust traveling to cold places can cause increased snow melt.

Sharp mountain peaks are covered in splotches of snow with a fine coating of dust visible on top of the snow.

A coating of dust on snow speeds the pace of snowmelt in the spring. Credit: NASA | + Expand image

Dust can affect air temperatures as well. For example, dust with more iron absorbs light and can cause the air to warm, while dust with less iron reflects light and is responsible for local cooling. Iron in dust can also act as a fertilizer for plankton in oceans, supplying them with nutrients needed for growth and reproduction.

A plume of dust eminates from over the Copper River in Alaska, spreading out as this series of overhead satellite images progresses.

A plume of dust is shown emanating from over Alaska's Copper River in October 2016 in these images captured by the Moderate Resolution Imaging Spectroradiometer, or MODIS, instrument on NASA’s Terra and Aqua satellites. Dust storms play a key role in fueling phytoplankton blooms by delivering iron to the Gulf of Alaska. Credit: NASA | › Full image and caption

Floating dust potentially alters the composition of clouds and how quickly or slowly they form, which can ultimately impact weather patterns, including the formation of hurricanes. That’s because clouds need particles to act as seeds around which droplets of moisture in the atmosphere can form. This process of coalescing water particles, called nucleation, is one factor in how clouds form.

An overhead view of a swirl of clouds mixed with a streak of dust like a swirl of milk froth in a cappuccino

A swirl of dust mixes with the clouds in a low-pressure storm over the Gobi desert between Mongolia and China. This image was captured by the MODIS instrument on the Terra satellite in May 2019. Credit: NASA | › Full image and caption

Thanks to EMIT, we’ll take the first steps in understanding how the movements of dust particles contribute to local and global changes in climate by producing “mineral maps”. These mineral maps will reveal differences in the chemical makeup of dust, providing essential information to help us model the way dust can transform Earth’s climate.

› Learn more about what EMIT will do from JPL News

How It Works

NASA has been exploring how dust moves across the globe by combining on-the-ground field studies with cutting-edge technology.

Dr. Olga Kalashnikova, an aerosol scientist at NASA's Jet Propulsion Laboratory and a co-investigator for EMIT, has been using satellite data to study atmospheric mineral dust for many years, including tracking the movements of dust and investigating trends in the frequency of dust storms.

As Dr. Kalashnikova describes, “From the ground, we can see what types of dusts are lifted into the atmosphere by dust storms on a local scale, but with EMIT, we can understand how they differ and where they originally came from.”

EMIT is the first instrument designed to observe a key part of the mineral dust cycle from space, allowing scientists to track different dust compositions on a global scale, instead of in just one region at a time. To understand dust’s impact on Earth’s climate, scientists will use EMIT to answer key questions, including:

  • How does dust uplifted in the atmosphere alter global temperatures?
  • What role do dusts play in fertilizing our oceans when they are deposited?
  • How do dust particles in the atmosphere affect cloud nucleation; the process by which clouds are ‘seeded’ and begin to coalesce into larger clouds?
A picture of the EMIT instrument, shaped like a small megaphone, is overlaid on an picture of the International Space Station flying above Earth.

The EMIT instrument will fly aboard the International Space Station, which orbits Earth about once every 90 minutes, completing about 16 orbits per day. Credit: NASA | + Expand image

To achieve its objectives, EMIT will spend 12 months collecting what are called “hyperspectral images” of some of the most arid regions of our planet selected by scientists and engineers as areas of high dust mobility, such as Northern Africa, the Middle East, and the American Southwest.

These images are measurements of light reflected from the Earth below, calibrated to the distinct patterns, or spectra, of light we see when certain minerals are present. The EMIT team has identified 10 minerals that are most common, including gypsum, hematite, and kaolinite.

Bands of satellite images looking at a seciton of Earth are highlighted in different colors to reveal different concentrations of minerals.

This example spectra shows how scientists will be able to identify different concentrations of minerals and elements in data collected by EMIT. Credit: NASA/JPL-Caltech | + Expand image

Why are these minerals important? One key reason is the presence or absence of the element iron, found in some minerals but not others.

Dr. Bethany Ehlmann is a planetary scientist and co-investigator for the EMIT project at Caltech and explains that when it comes to heating, “a little bit of iron goes a long way.” Iron in minerals absorbs visible and infrared light, meaning that even if only a small amount is present, it will result in a much warmer dust particle. Large amounts of warm dust in our atmosphere may have an impact on temperatures globally since those dust particles radiate heat as they travel, sometimes as far as across oceans!

Collecting images from space is, of course, no easy task, especially when trying to look only at the ground below. Yet it does allow scientists to get a global picture that's not possible to capture from the ground. Field studies allow us to take individual samples from tiny places of interest, but from space, we can scan the entire planet in remote places where no scientist can visit.

The International Space Station flies over Earth as a radar beam shines down over a desert area, making a colorful data map of its obversations.

Event: EMIT Launch

Learn more about the launch and find out how to get students engaged with the project using STEM education resources from JPL.

Of course, there are some complications in trying to study the light reflected off the surface of Earth, such as interference from clouds. To prevent this problem, the EMIT team plans to collect data at each location several times to ensure that the images aren’t being obscured by clouds between the instrument and the minerals we’re looking for.

The data collected by EMIT will provide a map of the compositions of dust from dry, desert environments all over the world, but the team involved won’t stop there. Knowing more about what the dust is made of sets the stage for a broader understanding of a few more of the complex processes that make up our global climate cycle. Upon completion of this study, EMIT's mineral maps will support further campaigns to complete our global dust picture. For example, NASA hopes to couple the data from EMIT with targeted field campaigns, in which scientists can collect wind-blown dust from the ground to learn more about where dust particles move over time and answer questions about what types of dust are on the go.

Furthermore, missions such as the Multiangle Imager for Aerosols, or MAIA, will allow us to better understand the effects of these dust particles on air-quality and public health.

Teach it

Studying Earth’s climate is a complex puzzle, consisting of many trackable features. These can range from sea level to particles in our atmosphere, but each makes a contribution to measuring the health of our planet. Bring EMIT and NASA Earth Science into your classroom with these lessons, articles, and activities to better understand how we’re exploring climate change.

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TAGS: Earth, climate, geology, weather, EMIT, Teachers, Classroom, Lessons, Earth Science, Climate Change, Dust, Global Warming, Educators, K-12, Teachable Moments, Climate TM

  • Brandon Rodriguez
    ABOUT THE AUTHOR

    Brandon Rodriguez, Educator Professional Development Specialist, NASA-JPL Education Office

    Brandon Rodriguez is the educator professional development specialist at NASA’s Jet Propulsion Laboratory. Outside of promoting STEM education, he enjoys reading philosophy, travel and speaking to your dog like it's a person.

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Teachable Moments | March 10, 2022

Pi Goes to Infinity and Beyond in NASA Challenge

By Lyle Tavernier

Collage of spacecraft featured in the 2022 NASA Pi Day Challenge

Graphic showing the various spacecraft featured in the 2022 NASA Pi Day Challenge overlaid with text that reads NASA Pi Day Challenge Answers

Learn about pi and some of the ways the number is used at NASA. Then, dig into the science behind the Pi Day Challenge.

Update: March 15, 2022 – The answers are here! Visit the NASA Pi Day Challenge slideshow to view the illustrated answer keys for each of the problems in the 2022 challenge.

Jump To

In the News

No matter what Punxsutawney Phil saw on Groundhog Day, a sure sign that spring approaches is Pi Day. Celebrated on March 14, 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.

Every year, Pi Day gives us a reason to not only celebrate the mathematical wonder that helps NASA explore the universe, but also to enjoy our favorite sweet and savory pies. Students can join in the fun by using pi to explore Earth and space themselves in our ninth annual NASA Pi Day Challenge.

Read on to learn more about the science behind this year's challenge and find out how students can put their math mettle to the test to solve real problems faced by NASA scientists and engineers as we explore Earth, the Moon, Mars, and beyond!
Infographic of all of the Pi in the Sky 9 graphics and problems

Visit the Pi in the Sky 9 lesson page to explore classroom resources and downloads for the 2022 NASA Pi Day Challenge. Image credit: NASA/JPL-Caltech | + Expand image

An spacecraft orbiting the Moon shines a laser into a dark crater.

This artist's concept shows the Lunar Flashlight spacecraft, a six-unit CubeSat designed to search for ice on the Moon's surface using special lasers. Image credit: NASA/JPL-Caltech | › Full image details

Dome-covered seismometer sits on the surface of Mars while clouds pass overhead.

Clouds drift over the dome-covered seismometer, known as SEIS, belonging to NASA's InSight lander, on Mars. Credit: NASA/JPL-Caltech. | › Full image and caption

The SWOT spacecraft passes over Florida, sending signals and collecting data.

This animation shows the collection of data over the state of Florida, which is rich with rivers, lakes and wetlands. Credits: NASA/JPL-Caltech | + Expand image

A spacecraft points to a star that has three planets orbiting it.

Illustration of NASA’s Transiting Exoplanet Survey Satellite (TESS). Credits: NASA | + Expand image

How It Works

Dividing any circle’s circumference by its diameter gives you an answer of pi, which is usually rounded to 3.14. Because pi is an irrational number, its decimal representation goes on forever and never repeats. In 2021, a supercomputer calculated pi to more than 62 trillion digits. But you might be surprised to learn that for space exploration, NASA uses far fewer digits of pi.

Here at NASA, we use pi to understand how much signal we can receive from a distant spacecraft, to calculate the rotation speed of a Mars helicopter blade, and to collect asteroid samples. But pi isn’t just used for exploring the cosmos. Since pi can be used to find the area or circumference of round objects and the volume or surface area of shapes like cylinders, cones, and spheres, it is useful in all sorts of ways. Architects use pi when designing bridges or buildings with arches; electricians use pi when calculating the conductance of wire; and you might even want to use pi to figure out how much frozen goodness you are getting in your ice cream cone.

In the United States, March 14 can be written as 3.14, which is why that date was chosen for celebrating all things pi. 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 that's precisely what the NASA Pi Day Challenge is all about!

The Science Behind the 2022 NASA Pi Day Challenge

This ninth installment of the NASA Pi Day Challenge includes four brain-busters that get students using pi to measure frost deep within craters on the Moon, estimate the density of Mars’ core, calculate the water output from a dam to assess its potential environmental impact, and find how far a planet-hunting satellite needs to travel to send data back to Earth.

Read on to learn more about the science and engineering behind the problems or click the link below to jump right into the challenge.

› Take the NASA Pi Day Challenge

› Educators, get the lesson here!

Lunar Logic

NASA’s Lunar Flashlight mission is a small satellite that will seek out signs of frost in deep, permanently shadowed craters around the Moon’s south pole. By sending infrared laser pulses to the surface and measuring how much light is reflected back, scientists can determine which areas of the lunar surface contain frost and which are dry. Knowing the locations of water-ice on the Moon could be key for future crewed missions to the Moon, when water will be a precious resource. In Lunar Logic, students use pi to find out how much surface area Lunar Flashlight will measure with a single pulse from its laser.

Core Conundrum

Since 2018, the InSight lander has studied the interior of Mars by measuring vibrations from marsquakes and the “wobble” of the planet as it rotates on its axis. Through careful analysis of the data returned from InSight, scientists were able to measure the size of Mars’ liquid core for the first time and estimate its density. In Core Conundrum, students use pi to do some of the same calculations, determining the volume and density of the Red Planet’s core and comparing it to that of Earth’s core.

Dam Deduction

The Surface Water and Ocean Topography, or SWOT mission will conduct NASA's first global survey of Earth's surface water. SWOT’s state-of-the-art radar will measure the elevation of water in major lakes, rivers, wetlands, and reservoirs while revealing unprecedented detail on the ocean surface. This data will help scientists track how these bodies of water are changing over time and improve weather and climate models. In Dam Deduction, students learn how data from SWOT can be used to assess the environmental impact of dams. Students then use pi to do their own analysis, finding the powered output of a dam based on the water height of its reservoir and inferring potential impacts of this quick-flowing water.

Telescope Tango

The Transiting Exoplanet Survey Satellite, or TESS, is designed to survey the sky in search of planets orbiting bright, nearby stars. TESS does this while circling Earth in a unique, never-before-used orbit that brings the spacecraft close to Earth about once every two weeks to transmit its data. This special orbit keeps TESS stable while giving it an unobstructed view of space. In its first two years, TESS identified more than 2,600 possible exoplanets in our galaxy with thousands more discovered during its extended mission. In Telescope Tango, students will use pi to calculate the distance traveled by TESS each time it sends data back to Earth.

Teach It

Celebrate Pi Day by getting students thinking like NASA scientists and engineers to solve real-world problems in NASA Pi Day Challenge. Completing the problem set and reading about other ways NASA uses pi is a great way for students to see the importance of the M in STEM.

Pi Day Resources

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

Recursos en español

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Facts and Figures

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TAGS: Pi Day, Pi, Math, NASA Pi Day Challenge, Moon, Lunar Flashlight, Mars, InSight, Earth, Climate, SWOT, Exoplanets, Universe, TESS, Teachers, Educators, Parents, Students, Lessons, Activities, Resources, K-12

  • Lyle Tavernier
    ABOUT THE AUTHOR

    Lyle Tavernier, Educational Technology Specialist, NASA-JPL Education Office

    Lyle Tavernier is an educational technology specialist at NASA's Jet Propulsion Laboratory. When he’s not busy working in the areas of distance learning and instructional technology, you might find him running with his dog, cooking or planning his next trip.

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Teachable Moments | January 24, 2022

Reflecting On Greenland’s Melting Glaciers as OMG Mission Concludes

By Ota Lutz

Just beyond the wing of a plane, the edge of a tall glacier is visible through the plane's window. At the bottom of the glacier, bits of ice surround an elliptical pool of brown water at the glacier's edge.

Explore how the OMG mission discovered more about what's behind one of the largest contributors to global sea level rise. Plus, learn what it means for communities around the world and how to get students engaged.

After six years investigating the effects of warming oceans on Greenland's ice sheet, the Oceans Melting Greenland, or OMG, mission has concluded. This airborne and seaborne mission studied how our oceans are warming and determined that ocean water is melting Greenland’s glaciers as much as warm air is melting them from above.

Read on to learn more about how OMG accomplished its goals and the implications of what we learned. Then, explore educational resources to engage students in the science of this eye-opening mission.

Activity Notes

Why It's Important

Global sea level rise is one of the major environmental challenges of the 21st century. As oceans rise, water encroaches on land, affecting populations that live along shorelines. Around the world – including U.S. regions along the Gulf of Mexico and Eastern Seaboard and in Alaska – residents are feeling the impact of rising seas. Additionally, freshwater supplies are being threatened by encroaching saltwater from rising seas.

Sea level rise is mostly caused by melting land ice (primarily glaciers), which adds water to the ocean, as well as thermal expansion, the increase in volume that occurs when water heats up. Both ice melt and thermal expansion result from rising global average temperatures on land and in the sea – one facet of climate change.

This short video explains why Greenland's ice sheets are melting and what it means for our planet. Credit: NASA/JPL-Caltech | Watch more from the Earth Minute series

Greenland’s melting glaciers contribute more freshwater to sea level rise than any other source, which is why the OMG mission set out to better understand the mechanisms behind this melting.

How We Did It

The OMG mission used a variety of instruments onboard airplanes and ships to map the ocean floor, measure the behemoth Greenland glaciers, and track nearby water temperature patterns.

Join JPL scientist Josh Willis as he and the NASA Oceans Melting Greenland (OMG) team work to understand the role that ocean water plays in melting Greenland’s glaciers. Credit: NASA/JPL-Caltech | Watch on YouTube

An animation shows a ship passing over the ocean directly in front of a glacier and scanning the sea floor followed by a plane flying overhead and scanning the air.

This animation shows how the OMG mission created a map of the ocean floor, known as a bathymetric map, to determine the geometry around Greenland's glaciers. Image credit: NASA/JPL-Caltech | + Expand image

An animation shows a plan flying over a glacier and scanning the ground below followed by a plane flying over the ocean shelf next to the glacier and dropping probes into the water.

This animation shows how the OMG mission used radar to measure changes in the thickness and retreat of Greenland's glaciers as well as probes to measure ocean temperature and salinity. Credit: NASA/JPL-Caltech | + Expand image

Early on, the mission team created a map of the ocean floor, known as a bathymetric map, by combining multibeam sonar surveys taken from ships and gravity measurements taken from airplanes. Interactions among glaciers and warming seas are highly dependent on the geometry of the ocean floor. For example, continental shelf troughs carved by glaciers allow pathways for water to interact with glacial ice. So understanding Greenland's local bathymetry was crucial to OMG's mission.

To locate the edges of Greenland's glaciers and measure their heights, the mission used a radar instrument known as the Glacier and Ice Surface Topography Interferometer. Every spring during the six-year OMG mission, the radar was deployed on NASA’s Gulfstream III airplane that flew numerous paths over Greenland’s more than 220 glaciers. Data from the instrument allowed scientists to determine how the thickness and area of the glaciers are changing over time.

Finally, to measure ocean temperature and salinity patterns, scientists deployed numerous cylindrical probes. These probes dropped from an airplane and fell through the water, taking measurements from the surface all the way to the ocean floor. Each probe relayed its information back to computers onboard the plane where ocean temperatures and salinity were mapped. Then, scientists took this data back to their laboratories and analyzed it for trends, determining temperature variations and circulation patterns.

What We Discovered

Prior to the OMG mission, scientists knew that warming air melted glaciers from above, like an ice cube on a hot day. However, glaciers also flow toward the ocean and break off into icebergs in a process called calving. Scientists had the suspicion that warmer ocean waters were melting the glaciers from below, causing them to break off more icebergs and add to rising seas. It wasn’t until they acquired the data from OMG, that they discovered the grim truth: Glaciers are melting from above and below, and warming oceans are having a significant effect on glacial melt.

This narrated animation shows warm ocean water is melting glaciers from below, causing their edges to break off in a process called calving. Credit: NASA | Watch on YouTube

What this means for our Earth's climate is that as we continue burning fossil fuels and contributing to greenhouse gas accumulation, the oceans, which store more than 90% of the heat that is trapped by greenhouse gases, will continue to warm, causing glaciers to melt faster than ever. As warming ocean water moves against glaciers, it eats away at their base, causing the ice above to break off. In other words, calving rates increase and sea level rises even faster.

Our oceans control our climate and affect our everyday lives, whether or not we live near them. With the pace of the melt increasing, our shorelines and nearby communities will be in trouble sooner than previously expected. And it’s not just the beaches that will be affected. If Greenland’s glaciers all melt, global sea levels will rise by over 24 feet (7.4 meters), bringing dramatic change to the landscapes of major cities around the world.

› Read more about OMG’s findings and how scientists are continuing their research through ongoing initiatives and projects.

Teach It

Check out these resources to bring the real-life STEM behind the mission into your teaching. With lessons for educators and student projects, engage students in learning about the OMG mission and NASA climate science.

Educator Guides

Student Projects

Articles

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Websites

Facts & Figures

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TAGS: Teachable Moment, Climate, Earth Science, Glaciers, Greenland, Ice, Sea Level Rise, Teachers, Educators, Parents, Lessons, Missions, Earth, Climate TM

  • Ota Lutz
    ABOUT THE AUTHOR

    Ota Lutz, K-12 Education Group Manager, NASA-JPL Education Office

    Ota Lutz is the manager of the K-12 Education Group at NASA’s Jet Propulsion Laboratory. When she’s not writing new lessons or teaching, she’s probably cooking something delicious, volunteering in the community, or dreaming about where she will travel next.

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Edu News | April 21, 2011

Earth Day Chat for Students

By NASA/JPL Edu

Two simulations of Earth with climate model overlays

Watch this 30-minute video chat where a NASA/JPL scientist answered pre-submitted student questions about Earth and climate.

Watch archived program on USTREAM

TAGS: Live, Chat, Earth Day, Climate

  • NASA/JPL Edu
    ABOUT THE AUTHOR

    NASA/JPL Edu

    NASA/JPL Edu supports science, technology, engineering and mathematics (STEM) education by providing NASA and JPL activities, resources and materials to educators and students in grades K-12 as well as STEM internships and research opportunities to higher education students and faculty.

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