Education News & Blogs – NASA Jet Propulsion Laboratory

Get ready for the April 8 total solar eclipse. Learn about the science behind solar eclipses, how to watch safely, and how to engage students in NASA science.

On April 8, 2024, a total solar eclipse will be visible across much of the central and northeastern United States, as well as parts of Mexico and Canada.

Whether you are traveling to the path of the total eclipse or will be able to step outside and watch the eclipse where you live, here's everything you need to know, including what to expect, how to watch safely, and how to engage in scientific observations and discovery with NASA.

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What Are Solar Eclipses?
How to Watch the Upcoming Solar Eclipse
What Solar Eclipses Mean for Science
Taking Eclipse Science Farther
Solar Eclipse Lessons and Projects
Explore More

What Are Solar Eclipses?

Solar eclipses occur when the Sun, the Moon, and Earth align. For this alignment to happen, two things need to be true. First, the Moon needs to be in the new moon phase, which is when the Moon’s orbit brings it between Earth and the Sun. Second, eclipses can only happen during eclipse seasons, which last about 34 days and occur just shy of every six months. An eclipse season is the time period when the Sun, the Moon, and Earth can line up on the same plane as Earth's orbit during a new or full moon. If a new moon happens during an eclipse season, the shadow cast by the Moon will land on Earth, resulting in a solar eclipse. Most of the time, because the Moon’s orbit is slightly tilted, the Moon’s shadow falls above or below Earth, and we don't get a solar eclipse.

Not all solar eclipses look the same. The distance between the Sun, the Moon, and Earth plays an important role in what we see during a solar eclipse. Even though the Moon is much smaller than the Sun (about 400 times smaller in diameter), the Sun and Moon look about the same size from Earth. This is because the Sun is about 400 times farther away than the Moon. But as the Moon travels its elliptical orbit around Earth, its size appears slightly larger when it is closer to Earth and slightly smaller when it is farther from Earth. This contributes to the different kinds of solar eclipses you might have heard about. For example:

During a total solar eclipse, the Moon is closer to Earth in its orbit and appears larger, completely blocking the Sun's disk. This allows viewers in the path of totality to see the Sun’s corona, which is usually obscured by the bright light of the Sun’s surface.

Whisps of white haze flare out around the blackened disk of the Moon, which completely covers the Sun's disk

This image of a total solar eclipse was captured on Aug. 21, 2017 from Madras, Oregon. Image credit: NASA/Aubrey Gemignani | › Full image and caption

An annular solar eclipse occurs when the Sun, Moon, and Earth are properly aligned, but the Moon is farther away in its orbit, so it does not completely cover the Sun's disk from our perspective. Annular eclipses are notable for the "ring of fire," a thin ring of the Sun’s disk that's still visible around the Moon during annularity. The name annular eclipse comes from the world of mathematics, where a ring shape is known as an annulus.

The bubbling surface of the Sun's disk and the surrounding haze of orange and yellow light can be seen as a ring around the blackened disk of the Moon.

On Jan. 4, 2017, the Hinode satellite captured these breathtaking images of an annular solar eclipse. Image credit: Hinode/XRT | › Full image and caption

Partial eclipses can happen for two reasons. First, viewers outside the path of totality during a total solar eclipse – or the path of annularity during an annular eclipse – will see only part of the Sun’s surface covered by the Moon. The other time a partial eclipse can occur is when the Moon is nearly above or below Earth in its orbit so only part of the Moon’s shadow falls on Earth. In this case, only part of the Sun’s surface will appear covered by the Moon.

The Sun appears to have a small bite taken out of the top of its yellow-orange disk. The bite grows in size in this sequence of three images.

The Sun appears partially eclipsed in this series of photos taken from NASA’s Johnson Space Center in Houston on Aug. 21, 2017. Image credit: NASA/Noah Moran | › Full image and caption

How to Watch the Upcoming Solar Eclipse

First, an important safety note: Do not look directly at the Sun or view any part of the partial solar eclipse without certified eclipse glasses or a solar filter. Read more below about when you can safely view the total solar eclipse without eclipse glasses or a solar filter. Visit the NASA Eclipse website for more information on safe eclipse viewing.

When following proper safety guidelines, witnessing an eclipse is an unparalleled experience. Many “eclipse chasers” have been known to travel the world to see solar eclipses. Here's what to expect on April 8, 2024:

The start time and visibility of the eclipse will depend on your location. You can use the interactive map below to find detailed eclipse information, including timing and coverage, by entering in your location. A list of some of the cities and start times along the path of totality is available on the NASA Science website.

Explore when and where to view the eclipse with this interactive map from NASA. Enter your zip code to see what will be visible in your viewing location and when to watch. Credit: NASA's Scientific Visualization Studio

The eclipse begins when the edge of the Moon first crosses in front of the disk of the Sun. This is called a partial eclipse and might look as if a bite has been taken out of the Sun.

It is important to keep your eclipse glasses on during all parts of the partial solar eclipse. The visible part of the Sun is tens of thousands of times brighter than what you see during totality. You can also use a pinhole camera to view the eclipse.

An approximately 115-mile-wide strip known as the path of totality is where the shadow of the Moon, or umbra, will fall on Earth. Inside this path, totality will be visible starting about 65 to 75 minutes after the eclipse begins.

If you are in the path of totality, it is safe to take off your eclipse glasses and look at the total eclipse only during totality. Be sure to put your glasses back on before the total phase ends and the surface of the Sun becomes visible again. Your viewing location during the eclipse will determine how long you can see the eclipse in totality. In the U.S., viewers can expect to see 3.5 to 5.5 minutes of totality.

After totality ends, a partial eclipse will continue for 60 to 80 minutes, ending when the edge of the Moon moves off of the disk of the Sun.

For more information about the start of the partial eclipse, the start and duration of totality, and the percentage of the Sun eclipsed outside the path of totality, find your location on this eclipse map.

On April 8, NASA Television will host a live broadcast featuring expert commentary and views from telescopes along the path of totality. Tune into the broadcast from 10 a.m. to 1 p.m. PDT (1 to 4 p.m. EDT) on the day of the eclipse.

Join NASA as a total solar eclipse moves across North America on April 8. Tune in from 10 a.m. to 1 p.m. PDT (1 to 4 p.m. EDT) for live views from across the path, expert commentary, live demos, and more. | Watch on YouTube

What Solar Eclipses Mean for Science

Solar eclipses provide a unique opportunity for scientists to study the Sun and Earth from land, air, and space, plus allow the public to engage in citizen science!

A solid red circle with a smaller white-outlined circle inside it is centered over the disk of the Sun. Streams of yellow, red, and orange shoot out from the Sun, all around the solid circle, while a large solar flare bursts out of the upper left portion of the circle. A time stamp in the corner reads 2000/02/27.

NASA’s Solar and Heliospheric Observatory, or SOHO, constantly observes the outer regions of the Sun’s corona using a coronagraph. Image credit: ESA/NASA/SOHO | + Expand image

Scientists measure incoming solar radiation, also known as insolation, to better understand Earth’s radiation budget – the energy emitted, reflected, and absorbed by our planet. Just as clouds block sunlight and reduce insolation, eclipses create a similar phenomenon, providing a great opportunity to study how increased cloud cover can impact weather and climate.

Solar eclipses can also help scientists study solar radiation in general and the structure of the Sun. On a typical day, the bright surface of the Sun, called the photosphere, is the only part of the Sun we can see. During a total solar eclipse, the photosphere is completely blocked by the Moon, leaving the outer atmosphere of the Sun (corona) and the thin lower atmosphere (chromosphere) visible. Studying these regions of the Sun’s atmosphere can help scientists understand solar radiation, why the corona is hotter than the photosphere, and the process by which the Sun sends a steady stream of material and radiation into space. Annular solar eclipses provide opportunities for scientists to practice their observation methods so that they'll be ready when a total solar eclipse comes around.

Citizen scientists can get involved in collecting data and participating in the scientific process during the eclipse through NASA’s GLOBE program. Anyone in the path of the eclipse and in partial eclipse areas can act as citizen scientists by measuring temperature and cloud cover data and report it using the GLOBE Observer app to help further the study of how eclipses affect Earth’s atmosphere.

Visit NASA's Eclipse Science page to learn more about the many ways scientists are using the eclipse to improve their understanding of Earth, the Moon, and the Sun.

Taking Eclipse Science Farther

Eclipses also make a great jumping-off point to concepts and techniques used in astrophysics and our search for planets beyond our solar system.

Similar to a solar eclipse, a transit occurs when a planet crosses in front of the face of a star. From Earth, the planets Venus and Mercury can occasionally be seen transiting in front of the Sun, appearing as small, dark dots. Transits are also useful for detecting exoplanets – distant planets around other stars. When an exoplanet passes in between its star and Earth, we can measure tiny dips in the star's brightness that tell scientists a planet is there even when it’s too small to see.

Another way that eclipse concepts are used for astrophysics is with coronagraphs, mechanisms inside telescopes that block the light from a star. By creating a sort of artificial eclipse, coronagraphs help scientists search for exoplanets by making much dimmer planets orbiting a star easier to see. For example, NASA’s Nancy Grace Roman Telescope, slated for launch later this decade, will use an advanced coronagraph to analyze and directly image planets that orbit other stars. Learn more about the astrophysics involved in eclipses, including the use of gravitational lensing to study background objects, from NASA’s Universe of Learning.

Learn how the coronagraph instrument on the Nancy Grace Roman Telescope will allow the spacecraft to peer at the universe through some of the most sophisticated sunglasses ever designed. | Watch on YouTube

Solar Eclipse Lessons and Projects

Use these standards-aligned lessons, plus related activities and resources, to get your students excited about the eclipse and the science that will be conducted during the eclipse.

Explore More

Eclipse Info

Eclipse Safety

Interactives

Citizen Science

NASA GLOBE App

Facts & Figures

NASA's Universe of Learning materials are based upon work supported by NASA under award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Center for Astrophysics | Harvard & Smithsonian, and the Jet Propulsion Laboratory.

TAGS: Solar Eclipse, Eclipse, Annular Eclipse, K-12 Education, Lessons, Classroom Resources, STEM Resources

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.

Learn how pi is used by NASA and how many of its infinite digits have been calculated, then explore the science and engineering behind the 2024 Pi Day Challenge.

Update: March 15, 2024 – The answers to the 2024 NASA Pi Day Challenge are here! Take a peek at the illustrated answer key now available under each problem on the NASA Pi Day Challenge page.

This year marks the 11th installment of the NASA Pi Day Challenge. Celebrated on March 14, Pi Day is 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 on March 14, Pi Day gives us a reason to enjoy our favorite sweet and savory pies and celebrate the mathematical wonder that helps NASA explore the universe. Students can join in the fun once again by using pi to explore Earth and space themselves with the NASA Pi Day Challenge.

Read on to learn more about the science behind this year's challenge and get students solving real problems faced by NASA scientists and engineers exploring Earth, the Moon, asteroids, and beyond!

Jump To

What is Pi?
The Science Behind the 2024 NASA Pi Day Challenge
Bring the Challenge Into the Classroom
More Pi Day Resources

Infographic of all of the Pi in the Sky 11 graphics and problems

Visit the Pi in the Sky 11 lesson page to explore classroom resources and downloads for the 2024 NASA Pi Day Challenge. Image credit: NASA/JPL-Caltech | + Expand image

What is Pi

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 2022, mathematician Simon Plouffe discovered the formula to calculate any single digit of pi. In the same year, teams around the world used cloud computing technology to calculate pi to 100 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 map the Moon, measure Earth’s changing surface, receive laser-coded messages from deep space, and calculate asteroid orbits. 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. Transportation teams use pi when determining the size of new subway tunnels. Electricians can use pi when calculating the current or voltage passing through circuits. And you might even use pi to figure out how much fencing is needed around a circular school garden bed.

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 2024 NASA Pi Day Challenge

This 11th installment of the NASA Pi Day Challenge includes four illustrated math problems designed to get students thinking like scientists and engineers to calculate how to get a laser message to Earth, the change in an asteroid’s orbit, the amount of data that can be collected by an Earth satellite, and how a team of mini rovers will map portions of the Moon’s surface.

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

› Take the NASA Pi Day Challenge

› Educators, get the lesson here!

Receiver Riddle

In December 2023, NASA tested a new way to communicate with distant spacecraft using technology called Deep Space Optical Communications, or DSOC. From 19,000,000 miles (30,199,000 km) away, the Psyche spacecraft beamed a high-definition video encoded in a near-infrared laser to Earth. The video, showing a cat named Taters chasing a laser, traveled at the speed of light, where it was received at Caltech’s Palomar Observatory. Because of the great distance the laser had to travel, the team needed to aim the transmission at where Earth would be when the signal arrived. In Receiver Riddle, use pi to determine where along Earth's orbit the team needed to aim the laser so that it could be received at the Observatory at the correct moment.

This animation shows how DSOC's laser signals are sent between the Psyche spacecraft and ground stations on Earth - first as a pointing reference to ensure accurate aiming of the narrow laser signal and then as a data transmission to the receiving station. Credit: NASA/JPL-Caltech/ASU| Watch on YouTube

Daring Deflection

In 2022, NASA crashed a spacecraft into the asteroid Dimorphos in an attempt to alter its orbit. The mission, known as the Double Asteroid Redirection Test, or DART, took place at an asteroid that posed no threat to our planet. Rather, it was an ideal target for NASA to test an important element of its planetary defense plan. DART was designed as a kinetic impactor, meaning it transferred its momentum and kinetic energy to Dimorphos upon impact, altering the asteroid's orbit. In Daring Deflection, use pi to determine the shape of Dimorphos’ orbit after DART crashed into it.

An animation shows the surface of an asteroid getting closer and closer. In the last several frames, the animation slows and details of the rocky surface come into view.

This image shows the final minutes of images leading up to the DART spacecraft's intentional collision with asteroid Dimorphos. Credit: NASA/Johns Hopkins APL | › Enlarge image

Orbit Observation

The NISAR mission is an Earth orbiting satellite designed to study our planet's changing ecosystems. It will collect data about Earth's land- and ice-covered surfaces approximately every 6 days, allowing scientists to study changes at the centimeter scale – an unprecedented level of detail. To achieve this feat, NISAR will collect massive amounts of data. In Orbit Observation, students use pi to calculate how much data the NISAR spacecraft captures during each orbit of Earth.

An illustration shows the NISAR spacecraft orbiting above Earth.

The NISAR satellite, shown in this artist’s concept, will use advanced radar imaging to provide an unprecedented view of changes to Earth’s land- and ice-covered surfaces. Credit: NASA/JPL-Caltech. | › Full image and caption

Moon Mappers

The CADRE project aims to land a team of mini rovers on the Moon in 2025 as a test of new exploration technology. Three suitcase-size rovers, each working mostly autonomously, will communicate with each other and a base station on their lunar lander to simultaneously measure data from different locations. If successful, the project could open the door for future multi-robot exploration missions. In Moon Mappers, students explore the Moon with pi by determining how far a CADRE rover drives on the Moon’s surface.

A small rover is attached to an elevated rack while two engineers hold their hands out toward the underside of the rover.

Engineers test the system that will lower three small rovers onto the lunar surface as part of the CADRE project. Credit: NASA/JPL-Caltech | › Full image and caption

Bring the Challenge Into the Classroom

Celebrate Pi Day by getting students thinking like NASA scientists and engineers to solve real-world problems in the NASA Pi Day Challenge. In addition to solving the 2024 challenge, you can also dig into the 40 puzzlers from previous challenges available in our Pi Day collection. 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.

Collection

Educator Guides – NASA Pi Day Challenge

Here's everything you need to bring the NASA Pi Day Challenge into the classroom.

Grades 4-12

Time Varies
Student Activity

NASA Pi Day Challenge

The entire NASA Pi Day Challenge collection can be found in one, handy collection for students.

Grades 4-12

Time Varies
Downloads

Can't get enough pi? Download this year's NASA Pi Day Challenge graphics, including mobile phone and desktop backgrounds:
- Pi in the Sky 11 Poster (PDF, 4.0 MB)
- DART Mission Background: Phone | Desktop
- CADRE Project Background: Phone | Desktop
- DSOC Background: Phone | Desktop
- NISAR Mission Background: Phone | Desktop
- 2024 Pi Day Medley Background: Phone | Desktop

More Pi Resources

Related Lessons for Educators

Related Activities for Students

Facts and Figures

Websites

Articles

Videos

Interactives

Eyes on Asteroids

TAGS: Pi Day, Pi, Math, NASA Pi Day Challenge, moon, earth, asteroid, psyche, DART, CADRE, NISAR DSOC

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.

Leap day, Feb. 29, happens every four years because of a mismatch between the calendar year and Earth's orbit. Learn how it works, and get students engaged in leap day STEM.

You may have noticed that there's an extra day on your calendar this year. That's not a typo – it's leap day! Leap day is another name for Feb. 29, a date that typically comes around every four years, during a leap year.

Why doesn't Feb. 29 appear on the calendar every year?

The length of a year is based on how long it takes a planet to revolve around the Sun. Earth takes about 365.2422 days to make one revolution around the Sun. That's about six hours longer than the 365 days that we typically include in a calendar year. As a result, every four years, we have about 24 extra hours that we add to the calendar at the end of February in the form of leap day.

Without leap day, the dates of annual events, such as equinoxes and solstices, would slowly shift to later in the year, changing the dates of each season. After only a century without leap day, summer wouldn’t start until mid-July!

But the peculiar adjustments don't end there. If Earth revolved around the Sun in exactly 365 days and six hours, this system of adding a leap day every four years would need no exceptions. However, Earth takes a little less time than that to orbit the Sun. Rounding up and inserting a 24-hour leap day every four years adds about 45 extra minutes to every four-year leap cycle. That adds up to about three days every 400 years. To correct for that, years that are divisible by 100 don't have leap days unless they’re also divisible by 400.

If you do the math, you'll see that the year 2000 was a leap year, but 2100, 2200 and 2300 will not be.

Have students learn more about leap years with this article from NASA's Space Place, then have them do the math for themselves with this leap day problem set. You can also have students write a letter or poem to be opened on the next leap day or get them learning about orbits across the solar system.

And since we've got an extra 24 hours this year, don't forget to take a little time to relax!

Educator Resources

Student Resources

TAGS: K-12 Education, Math, Leap Day, Leap Year, Events, Space, Educators, Teachers, Parents, Students, STEM, Lessons, Earth Science, Earth

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.

Get to know GUSTO and learn how to bring the science and engineering behind this unique balloon-based mission into the classroom.

A NASA balloon mission designed to study the interstellar medium – the space between stars – will take to the skies above Antarctica in December 2023.

Read on to learn how the GUSTO mission's unique design and science goals can serve as real-life examples of STEM concepts. Then, explore lessons and resources you can use to get students learning more.

Jump To

What the GUSTO Mission Will Do
Why Fly on a Balloon?
Location is Everything
Preparing for Liftoff
Bring GUSTO Into the Classroom

What the GUSTO Mission Will Do

Though many people think of space as empty except for things like stars, planets, moons, asteroids, meteors, and comets, it’s anything but. Typically, there is one molecule of matter in every cubic centimeter of the space between stars known as the interstellar medium. In more dense clouds of interstellar gas, there could be as many as 1,000,000 molecules per cubic centimeter. It might not seem like much compared with the 10,000,000,000,000,000,000 molecules in every cubic centimeter of air we breathe, but the interstellar medium can tell us a lot about how stars and planets form and what role gases and dust play in our galaxy and others.

Star-forming nebulas birth Sun-like stars, which turn into red giants, then planetary nebulae, then white dwarfs. Massive stars are also born from star-forming nebulas and become red supergiants, then supernova, then either black holes or neutron stars.

This diagram shows the life cycles of Sun-like and massive stars. Credit: NASA, Night Sky Network | › Learn more about star life cycles

Like plants and animals, stars have a life cycle that scientists want to better understand. Gases and dust grains that make up a dense interstellar cloud, known as a nebula, can become disturbed, and under the pull of their own gravity, begin collapsing in on themselves. Eventually stars form from the gas and planets form from the dust. As a star goes through its life, it eventually runs out of sources of energy. When this happens, the star dies, expelling gases – sometimes violently, as in a supernova – into a new gas cloud. From here, the cycle can start again. Scientists want to know more about the many factors at play in this cycle. This is where GUSTO comes in.

GUSTO – short for Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory – is a balloon-based telescope that will study the interstellar medium, the small amount of gas and dust between the stars. From its vantage point high above almost all of the Earth’s atmosphere, GUSTO will measure carbon, nitrogen, and oxygen emissions in the far-infrared portion of the electromagnetic spectrum, focusing its sights on the Milky Way galaxy and the nearby galaxy known as the Large Magellanic Cloud.

A speckled field of bluish stars is intersected by a diagonal strip of purple and brown clouds covering a glowing yellow band beyond.

Our galaxy, the Milky Way, has hundreds of billions of stars and enough gas and dust to make billions more stars. Credit: NASA | › Full image and caption

The mission is designed to provide scientists with data that will help them understand the complete lifecycle of the gas and dust that forms planets and stars. To achieve its goals, GUSTO will study:

The composition and formation of molecular clouds in these regions.
The formation, birth, and evolution of stars from molecular clouds.
The formation of gas clouds following the deaths of stars. And the re-start of this cycle.

Thick clouds of purple and pastel pink cover a speckled field of stars with clusters of large and especially bright blue and yellow stars glowing through the clouds.

Nearly 200,000 light-years from Earth, the Large Magellanic Cloud is a satellite galaxy of the Milky Way. Vast clouds of gas within it slowly collapse to form new stars. In turn, these light up the gas clouds in a riot of colors, visible in this image from the Hubble Space Telescope. Credit: NASA | › Full image and caption

Scientists hope to use the information collected by GUSTO to develop models of the Milky Way and Large Magellanic Cloud. Studying these two galaxies allows scientists to observe more details and make more accurate models. Those models can then be used for comparing and studying more distant galaxies that are harder to observe.

Why Fly on a Balloon?

Unlike most NASA missions, GUSTO won’t launch on a rocket. It will be carried to approximately 120,000 feet (36.5 kilometers) above Antarctica using what’s known as a Long Duration Balloon, or LDB.

Balloon missions provide a number of advantages to scientists conducting research. They are more affordable than missions that go to space and require less time to develop. They also offer a way to test new scientific instruments and technologies before they are used in space. For these reasons, balloons have become a popular way for university students to gain experience building and testing science instruments.

Explore how balloons are being used for Earth and space science in this video from the Johns Hopkins Applied Physics Laboratory, which is providing the mission operations for GUSTO and the balloon gondola where the mission's instruments will be mounted. | Watch on YouTube

GUSTO's use of the Long Duration Balloon provided by NASA’s Balloon Science Program offers several advantages over other types of scientific balloons. Conventional scientific balloons stay aloft for a few hours or a few days and rely on the balloon maintaining a line-of-sight to send and receive data. Long Duration Balloons use satellites for sending data and receiving commands and can stay afloat for a few weeks to a couple of months.

Made with a thin, strong, plastic film called polyethylene, LDBs are partially inflated with helium. As the balloon rises, the surrounding air pressure decreases, allowing the gas inside the balloon to expand, increasing the volume and pressure of the balloon. When fully expanded, the balloon has a volume of around 40 million cubic feet (1.1 million cubic meters). That’s big enough to fit an entire football stadium inside.

An A-frame support structure with two sets of wing-like solar panels extending from its sides floats above Earth holding a telescope at its center.

GUSTO will be attached to a balloon gondola like the one depicted in this artist's rendering. | + Expand image

The telescope itself will be attached to a platform known as a gondola, which is home to several components that make the mission possible. The multi-axis control system will keep the platform stable during flight, allowing for precisely pointing GUSTO’s 35-inch (90-centimeter) diameter telescope in the right direction. Cryocoolers and liquid helium will keep the telescope’s scientific instruments at the necessary low temperature of -452°F (4° Kelvin). And the gondola will house a radio system that allows operators on the surface to control the balloon and telescope. All these systems will be powered by lithium-ion batteries charged during flight by a set of solar arrays.

Location is Everything

GUSTO is designed to measure terahertz wavelengths (in the far-infrared portion of the electromagnetic spectrum), a range of energy that is easily absorbed by water vapor. However, the observatory's altitude will put it in the upper half of the stratosphere and above 99% of the water vapor in the atmosphere. This makes it an ideal location for the mission to make its measurements and avoid factors that might otherwise obstruct its view.

GUSTO will make its observations from the upper half of the stratosphere, which offers several benefits over observing from lower in the atmosphere or from the ground. Credit: NASA | › Explore the interactive graphic

The stratosphere offers another advantage for GUSTO. This layer of the atmosphere warms as altitude increases, making the top of the stratosphere warmer than the bottom. The colder air at the bottom and warmer air at the top prevents mixing and air turbulence, making the air very stable and providing a great place to observe space. You may have noticed this stability if you’ve seen a flat-topped anvil-shaped storm cloud. That flat top is the cloud reaching the bottom of the stratosphere, where the stable air prevents the cloud from mixing upward.

But why fly GUSTO above Antarctica? Even though balloons can be launched from all over the planet, the 24 hours of sunlight per day provided by the Antarctic summer make the south polar region an ideal launch location for a solar-powered mission like GUSTO. But more important is a weather phenomenon known as an anticyclone. This weather system is an upper-atmosphere counter-clockwise wind flow that circles the South Pole about every two weeks. The Antarctic anticyclone allows for long balloon flights of missions that can be recovered and potentially reflown.

Preparing for Liftoff

To launch a balloon mission in Antarctica, weather conditions have to be just right. The anticyclone typically forms in mid-December but can arrive a little earlier or a little later. Even with the anticyclone started, winds on the ground and in the first few hundred feet of the atmosphere need to be under six knots (seven miles per hour) for GUSTO to launch. A NASA meteorologist provides daily updates on the cyclone and the ground.

Once weather conditions are good and the balloon is launched, it will circle Antarctica about once every 14 days with the wind. The anticyclone typically lasts one to two months. Because GUSTO may be in the air for more than two months, it’s possible that the mission will continue after the anticyclone ends, causing the balloon to drift northward as winter progresses.

Bring GUSTO Into the Classroom

The GUSTO mission is a great opportunity to engage students with hands-on learning opportunities. Students can build a planetary exploration balloon and model how interstellar dust forms into planets. Explore these lessons and resources to get students excited about the STEM involved in the mission.

Resources for Educators

Resources for Students

NASA's Universe of Learning materials are based upon work supported by NASA under award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Center for Astrophysics | Harvard & Smithsonian, and the Jet Propulsion Laboratory.

TAGS: GUSTO, Astronomy, Astrophysics, Science, Teaching, Learning, K-12, Classroom, Teachable Moments, Universe of Learning, Balloon Mission, Missions

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.

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 wielding the force.

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Why It's Important
How It Works
Teach It
Explore More

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.

May the 4th Lessons

Celebrate Star Wars Day with these standards-aligned lessons in motion and forces for grades K-12.

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.

Educator Guides

Student Activities

Using the Force

Stay on target, make a hovercraft, and explore more independent projects for students all about motion and forces.

Grades K-12

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