TAGS: InSight, Lessons, K-12, Activities, Teaching, STEM, Mars

• 

  ABOUT THE AUTHOR

  Ota Lutz, STEM Elementary and Secondary Education Specialist, NASA/JPL Edu

  Ota Lutz is a STEM elementary and secondary education specialist 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.

Explore More

Join the Conversation

• Join the conversation and share your Pi Day Challenge answers with @NASAJPL_Edu on social media using the hashtag #NASAPiDayChallenge
• Pi Day: What’s Going ‘Round – Tell us what you’re up to this Pi Day and share your stories and photos with NASA.

Standards-Aligned Lessons

• Pi in the Sky 5
• Pi in the Sky 4
• Pi in the Sky 3
• Pi in the Sky 2
• Pi in the Sky
• Pi in the Sky Challenge (slideshow for students)
  

Multimedia

• 18 Ways NASA Uses Pi – Whether it's sending spacecraft to other planets, driving rovers on Mars, finding out what planets are made of or how deep alien oceans are, pi takes us far at NASA. Find out how pi helps us explore space.
• Kepler-186f Travel Poster
  
• Video: First Interstellar Asteroid Wows Scientists
• Planet Pi
  

Facts and Figures

• Mars
• Jupiter
• exoplanet Kepler-186f
• asteroid 'Oumuamua

Missions

• InSight
• Juno
• Kepler
• Transiting Exoplanet Survey Satellite (TESS)

Websites

• Mars Exploration
• Solar System Exploration
• Exoplanets

TAGS: Pi Day, Math, Science, Engineering, NASA Pi Day Challenge, K-12, Lesson, Activity, Slideshow, Mars, Jupiter, Exoplanets, Kepler, Kepler-186f, Juno, InSight, TESS, ‘Oumuamua, asteroid, asteroids, NEO, Nearth Earth Object

• 

  ABOUT THE AUTHOR

  Lyle Tavernier, Educational Technology Specialist, NASA/JPL Edu

  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.

Why It’s Important

Lessons About the Moon

Explore our collection of standards-aligned lessons for grades 1-12.

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

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

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

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

What to Expect

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

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

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

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

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

At 2:51 a.m. PST on January 31, 2018, the edge of the Moon will begin entering the penumbra. The Moon will dim very slightly for the next 57 minutes as it moves deeper into the penumbra. Because this part of Earth’s shadow is not fully dark, you may only notice some dim shading (if anything at all) on the Moon near the end of this part of the eclipse. Should you decide to sleep in during this time, you won’t miss much.

At 3:48 a.m. PST, the edge of the Moon will begin entering the umbra. As the Moon moves into the darker shadow, significant darkening will be noticeable. Some say that during this part of the eclipse, the Moon looks as if it has had a bite taken out of it. That “bite” gets bigger and bigger as the Moon moves deeper into the shadow. If you will be on the East Coast of the United States, you might still be able to see the Moon just as it moves into the umbra before the Moon sets and the Sun rises.

At 4:51 a.m. PST, the Moon will be completely inside the umbra, marking the beginning of the total lunar eclipse. The moment of greatest eclipse, when the Moon is halfway through the umbra, occurs at 5:31 a.m. PST.

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

A variety of factors affect the appearance of the Moon during a total lunar eclipse. Clouds, dust, ash, photochemical droplets and organic material in the atmosphere can change how much light is refracted into the umbra. Additionally, the January 2018 lunar eclipse takes place when the full moon is at or near the closest point in its orbit to Earth (popularly known as a supermoon). This means it is deeper inside the umbra shadow and therefore may appear darker. The potential for variation provides a great opportunity for students to observe and classify the lunar eclipse based on its brightness. Details can be found below in the “Teach It” section.

At 6:07 a.m. PST, the edge of the Moon will begin exiting the umbra and moving into the opposite side of the penumbra. This marks the end of the total lunar eclipse.

At 7:11 a.m. PST, the Moon will be completely outside of the umbra. It will continue moving out of the penumbra until the eclipse ends at 8:08 a.m.

Teach It

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

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

• *NEW* Evaluating a Lunar Eclipse (Grades 3-12) - Students use the Danjon Scale of Lunar Eclipse Brightness to illustrate the range of colors and brightness the Moon can take on during a total lunar eclipse.
• Observing the Moon (Grades K-6) - Students identify the Moon’s location in the sky and record their observations in a journal over the course of the moon-phase cycle.
• Moon Phases (Grades 1-6) - Students learn about the phases of the Moon by acting them out. In 30 minutes, they will act out one complete, 30-day, Moon cycle.
• Measuring the Supermoon (Grades 5-12) - Students take measurements of the Moon during its full phase over multiple Moon cycles to compare and contrast results.
• Modeling the Earth-Moon System (Grades 6-8) – Students learn about scale models and distance by creating a classroom-size Earth-Moon system.
• Make a Moon Phases Calendar and Calculator – Like a decoder wheel for the Moon, this calendar will show you where and when to see the Moon and every moon phase throughout the year!

Explore More

• Try these related resources for students from NASA's Space Place:
• Lunar Eclipses and Solar Eclipses – This guide for kids provides an overview of lunar and solar eclipses.
• Why Does the Moon Have Craters? – Check out NASA's Space Place for the answer, written just for kids.
• NASA Moon Website – Find out more about the Moon and the NASA robots and humans who have visited it.

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

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  ABOUT THE AUTHOR

  Lyle Tavernier, Educational Technology Specialist, NASA/JPL Edu

  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.

A poster highlights the main characteristics of Explorer 1 and the Jupiter C rocket that launched it into space. Image credit: NASA

How They Did It

At the height of competition for access to space, the U.S. and the Soviet Union were both building satellites that would ride atop rockets in a quest to orbit Earth. The Soviets launched Sputnik 1 on October 4, 1957. Shortly thereafter, on January 31, 1958, the U.S. launched Explorer 1, the satellite that would begin a new age of scientific space exploration.

Using rockets to do science from orbit was a brand-new option in the late 1950s. Before this time, rockets had only been used for military operations and atmospheric research. Still, rockets of that era weren’t very reliable and none had been powerful enough to place an object into Earth orbit.

Rocket Activities

Explore our collection of standards-aligned lessons for grades K-9.

In order to lift Explorer 1 to its destination in Earth orbit, an existing U.S. Army rocket, the Jupiter C, was fitted with a fourth stage, provided by the Jet Propulsion Laboratory in Pasadena, California. For this stage, a rocket motor was integrated into the satellite itself. The new, four-stage rocket was called “Juno 1.”

Prior to these first orbiting observatories, everything we knew about space and Earth came from Earth-based observation platforms – sensors and telescopes – and a few atmospheric sounding rockets. With the success of Explorer 1 and the subsequent development of more powerful rockets, we have been able to send satellites beyond Earth orbit to explore planets, moons, asteroids and even our Sun. With a space-based view of Earth, we are able to gain a global perspective and acquire a wide variety and amount of data at a rapid pace.

Why It’s Important

This photograph shows the scientific instruments mounted inside Explorer 1 alongside its outer case. Image Credit: James A. Van Allen Papers (RG 99.0142), University Archives, The University of Iowa Libraries

This graphic shows the various components and science instruments aboard Explorer 1, including its primary science instrument, a cosmic ray detector. Image credit: NASA/JPL-Caltech

This graphic shows a cutaway diagram of the Van Allen belts along with the locations of a few Earth-orbiting spacecraft, including the Van Allen Probes. Image credit: NASA

The primary science instrument on Explorer 1 was a cosmic ray detector designed to measure the radiation environment in Earth orbit – in part, to understand what hazards future spacecraft (or space-faring humans) might face. Once in space, this experiment, provided by James Van Allen of the University of Iowa, revealed a much lower cosmic ray count than expected. Van Allen theorized that the instrument might have been saturated by very strong radiation from a belt of charged particles trapped in space by Earth's magnetic field. The existence of the radiation belts was confirmed over the next few months by Explorer 3, Pioneer 3 and Explorer 4. The belts became known as the Van Allen radiation belts in honor of their discoverer.

Although we discovered and learned a bit about the Van Allen belts with the Explorer missions, they remain a source of scientific interest. The radiation belts are two (or more) donut-shaped regions encircling Earth, where high-energy particles, mostly electrons and ions, are trapped by Earth's magnetic field. The belts shrink and swell in size in response to incoming radiation from the Sun. They protect Earth from incoming high-energy particles, but this trapped radiation can affect the performance and reliability of our technologies, such as cellphone communication, and pose a threat to astronauts and spacecraft. It’s not safe to spend a lot of time inside the Van Allen radiation belts.

Most spacecraft are not designed to withstand high levels of particle radiation and wouldn’t last a day in the Van Allen belts. As a result, most spacecraft travel quickly through the belts toward their destinations, and non-essential instruments are turned off for protection during this brief time.

To conquer the challenge of extreme radiation in the belts while continuing the science begun by Explorer 1, NASA launched a pair of radiation-shielded satellites, the Van Allen Probes, in 2012. (The rocket that carried the Van Allen Probes into space was more than twice as tall as the rocket that carried Explorer 1 to orbit!)

The Van Allen Probes carry identical instruments and orbit Earth, following one another in highly elliptical, nearly identical orbits. These orbits bring the probes as close as about 300 miles (500 kilometers) above Earth’s surface, and take them as far out as about 19,420 miles (31,250 kilometers), traveling through diverse areas of the belts. By comparing observations from both spacecraft, scientists can distinguish between events that occur simultaneously throughout the belts, those that happen at only a single point in space, and those that move from one point to another over time.

Watch the video above to learn more about the Van Allen Probes and a discovery they made shortly after starting their mission. Credit: NASA Goddard

The Van Allen Probes carry on the work begun by Explorer 1 and, like all successful space missions, are providing answers as well as provoking more questions. NASA continues to explore Earth and space using spacecraft launched aboard a variety of rockets designed to place these observatories in just the right spots to return data that will answer and inspire questions for years to come.

Teach It

• *NEW* Build a Satellite (Grades 5-8) – Students will use the engineering design process to design, build, test and improve a model satellite intended to investigate the surface of a planet.
• Rocket Lessons and Activities (Grades K-9) – Use these exciting lessons to help your students experience the thrill of building their own rockets using the engineering design process!
• Earth Science Lessons and Activities (Grades K-12) – Use these lessons to engage your students in studying Earth from space!
• Build Your Own Space Mission – Have younger students play this game to place instruments aboard a spacecraft and launch it into space!
• Download the GLOBE Observer app and have students be citizen scientists in support of NASA Earth science missions! Learn more about how to participate.

Explore More

• Visit the Explorer 1 website

TAGS: Explorer 1, STEM, NASA in the Classroom, Lessons, Activities, Teachable Moments

• 

  ABOUT THE AUTHOR

  Ota Lutz, STEM Elementary and Secondary Education Specialist, NASA/JPL Edu

  Ota Lutz is a STEM elementary and secondary education specialist 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.

While they make for great photographs, images like this one that rely on a special photographic technique aren't an accurate representation of what the supermoon will look like to the naked eye. Credit: NASA/Bill Ingalls | Full image and caption on Flickr

A supermoon looks bigger than a "micromoon" (when the full moon is at apogee) because it's about 40,000 kilometers closer to Earth on average. Credit: NASA/JPL-Caltech

It's nearly impossible to compare the apparent size of the supermoon with a micromoon from memory, but when seen side-by-side as in this graphic, it becomes clear. Credit: NASA/JPL-Caltech

Leading up to a supermoon, there are often misleading images on popular media. A technique that involves using a long telephoto lens to take photographs of the Moon next to buildings or other objects makes the Moon look huge compared with its surroundings. This effect can make for great photographs, but it has nothing to do with the supermoon. In fact, these photos can be taken during any Moon phase, but they will likely be used in stories promoting the supermoon.

There are also images that have been edited to inaccurately dramatize the size of the supermoon. Both of these can lead students, and adults, taking pictures with their cell phone to think that they’ve done something wrong or just aren’t cut out for observing the sky, which isn’t true!

Your students may have noticed that when they see a full moon low on the horizon, it appears huge and then seems to shrink as it rises into the night sky. This can happen during any full moon. Known as the Moon Illusion, it has nothing to do with a supermoon. In fact, scientists still aren’t sure what causes the Moon Illusion.

Brightness

The full moon is bright and the supermoon is even brighter! Sunlight reflecting off the Moon during its full phase is bright enough to cast shadows on the ground. During a supermoon, that brightness can increase up to 30 percent as a result of the Moon being closer to Earth, a phenomenon explained by the inverse square law. (Introduce students to the inverse square law with this space-related math lesson for 6th- through 8th-graders.) As with the size of the Moon, students may not remember just how bright the last full moon was or easily be able to compare it. Powerful city lights can also diminish how bright a supermoon seems. Viewing it away from bright overhead street lights or outside the city can help viewers appreciate the increase in brightness.

What Not to Expect

A supermoon will not cause extreme flooding, earthquakes, fires, volcanic eruptions, severe weather, nor tsunamis, despite what incorrect and non-scientific speculators might suggest. Encourage your students to be good scientists and research this for themselves.

Teach It

The excitement and buzz surrounding a supermoon is a great opportunity to teach a variety of Moon topics with these lessons from JPL’s Education Office:

• *NEW* Observing the Moon (Grades K-6) – Students identify the Moon’s location in the sky and record their observations over the course of the moon-phase cycle in a journal.
• *NEW* Measuring the Supermoon (Grades 5-12) – Students take measurements of the Moon during its full phase over multiple Moon cycles to compare and contrast results.
• *NEW* Moon Phases Calendar and Calculator – Like a decoder wheel for the Moon, this calendar will show you where and when to see the Moon and every moon phase throughout the year!
• *NEW* Look at the Moon! Journaling Project – Draw what you see in a Moon Journal and see if you can predict the moon phase that comes next.
• Moon Phases (Grades 1-6) – Students learn about the phases of the Moon by acting them out. In 30 minutes, they will act out one complete Moon cycle.
• Whip Up a Moon-Like Crater (Grades 1-6) – Whip up a Moon-like crater with baking ingredients as a demonstration for students.
• Modeling the Earth-Moon System (Grades 6-8) – Using an assortment of playground and toy balls, students will measure diameter, calculate distance and scale, and build a model of the Earth-Moon system.

Explore More

• Learn more about the Moon on NASA's Moon website.

For the record: This story originally stated a supermoon would be visible in January and February 2018. The two supermoons of 2018 are both in January.

TAGS: Supermoon, Moon Phases, Moon, Earth's Moon, What's Up, Astronomy, K-12, Educators

• 

  ABOUT THE AUTHOR

  Lyle Tavernier, Educational Technology Specialist, NASA/JPL Edu

  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.

Why It's Important

Einstein published the Theory of General Relativity in 1915. In it, he predicted the existence of gravitational waves, which had never been directly detected until now. In 1974, physicists discovered that two neutron stars orbiting each other were getting closer in a way that matched Einstein’s predictions. But it wasn’t until 2015, when LIGO’s instruments were upgraded and became more sensitive, that they were able to detect the presence of actual gravitational waves, confirming the last important piece of Einstein’s theory.

It's also important because gravitational waves carry information about their inception and about the fundamental properties of gravity that can’t be seen through observations of the electromagnetic spectrum. Thanks to LIGO’s discovery, a new field of science has been born: gravitational wave astronomy.

How They Did It

LIGO consists of facilities in Washington and Louisiana. Each observatory uses a laser beam that is split and sent down 2.5-mile (4-kilometer) long tubes. The laser beams precisely indicate the distance between mirrors placed at the ends of each tube. When a gravitational wave passes by, the mirrors move a tiny amount, which changes the distance between them. LIGO is so sensitive that it can detect a change smaller than 1/10,000 the width of a proton (10^-19 meter). Having two observatories placed a great distance apart allows researchers to approximate the direction the waves are coming from and confirm that the signal is coming from space rather than something nearby (such as a heavy truck or an earthquake).

Teach It

Creating a model that demonstrates gravitational waves traveling through spacetime is as simple as making a gelatin universe!

› See the activity!

Middle school students can develop a model that shows gravitational waves traveling through spacetime while working toward the following Next Generation Science Standard:

• MS-PS4-2 - Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

Explore More

• Gravitational waves news, videos and resources
• Laser Interferometer Gravitational-Wave Observatory (LIGO) Website
  
  

TAGS: Gravitational Waves, Teachable Moment, LIGO, Black Holes, Einstein

• 

  ABOUT THE AUTHOR

  Lyle Tavernier, Educational Technology Specialist, NASA/JPL Edu

  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.

In this installment of the "Crazy Engineering" video series from NASA's Jet Propulsion Laboratory, host Mike Meacham talks to a Cassini engineer about astrodynamics and how it was used to design the Saturn mission's Grand Finale.

When Cassini passed close by Titan on April 22, the moon’s gravity pulled strongly on the spacecraft. The flyby gave Cassini a change in velocity of about 1,800 mph (800 meters per second) that sent the spacecraft into its first of the ring-gap orbits on April 23. On April 26, Cassini made its first of 22 daring plunges between the planet and its mighty rings.

This graphic illustrates Cassini's trajectory, or flight path, during the final two phases of its mission. The 20 Ring-Grazing Orbits that Cassini made between November and April 2017 are shown in gray; the 22 Grand Finale Orbits are shown in blue. The final partial orbit is colored orange. + Enlarge image

Clouds on Saturn take on the appearance of strokes from a cosmic brush thanks to the wavy way that fluids interact in Saturn's atmosphere. This images used in this false-color view were taken with the Cassini spacecraft narrow-angle camera on May 18, 2017. Image credit: NASA-JPL/Caltech/SSI | › Full image and caption

This animated image of Saturn's moon Enceladus is a composite of six images taken by the Cassini spacecraft on Aug. 1, 2017. Image credit: NASA-JPL/Caltech/SSI | › Full image and caption

These are the highest-resolution color images of any part of Saturn's rings, to date, showing a portion of the inner-central part of the planet's B Ring. The view is a mosaic of two images that show a region that lies between 61,300 and 65,600 miles (98,600 and 105,500 kilometers) from Saturn's center. Image credit: NASA-JPL/Caltech/SSI | › Full image and caption

As Kepler’s third law indicates, Cassini traveled faster than ever before during these final smaller orbits. Cassini's orbit continued to cross the orbit of Titan during these ring-gap orbits. And every couple of orbits, Titan passed near enough to give the spacecraft a nudge. One last nudge occured on September 11, placing the spacecraft on its final, half-orbit, impact trajectory toward Saturn.

Because a few hardy microbes from Earth might have survived onboard Cassini all these years, NASA has chosen to safely dispose of the spacecraft in the atmosphere of Saturn to avoid the possibility of Cassini someday colliding with and contaminating moons such as Enceladus and Titan that may hold the potential for life. Cassini will continue to send back science measurements as long as it is able to transmit during its final dive into Saturn.

Why It’s Important

Flying closer than ever before to Saturn and its rings has provided an unprecedented opportunity for science. During these orbits, Cassini’s cameras have captured ultra-close images of the planet’s clouds and the mysterious north polar hexagon, helping us to learn more about Saturn’s atmosphere and turbulent storms.

The cameras have been taking high-resolution images of the rings, and to improve our knowledge of how much material is in the rings, Cassini has also been conducting gravitational measurements. Cassini's particle detectors have sampled icy ring particles being funneled into the atmosphere by Saturn's magnetic field. Data and images from these observations are helping bring us closer to understanding the origins of Saturn’s massive ring system.

Cassini has also been making detailed maps of Saturn's gravity and magnetic fields to reveal how the planet is structured internally, which could help solve the great mystery of just how fast Saturn is rotating.

On its first pass through the unexplored 1,500-mile-wide (2,400-kilometer) space between the rings and the planet, Cassini was oriented so that its high-gain antenna faced forward, shielding the delicate scientific instruments from potential impacts by ring particles. After this first ring crossing informed scientists about the low number of particles at that particular point in the gap, the spacecraft was oriented differently for the next four orbits, providing the science instruments unique observing angles. For ring crossings 6, 7 and 12, the spacecraft was again oriented so that its high-gain antenna faced forward.

Fittingly, Cassini's final moments will be spent doing what it does best, returning data on never-before-observed regions of the Saturnian system. On September 15, just hours before Cassini enters Saturn's atmosphere for its Grand Finale dive, it will collect and transmit its final images back to Earth. During its fateful dive, Cassini will be sending home new data in real time informing us about Saturn’s atmospheric composition. It's our last chance to gather intimate data about Saturn and its rings – until another spacecraft journeys to this distant planet.

Explore the many discoveries made by Cassini and the story of the mission on the Cassini website.

Teach It

Use these standards-aligned lessons to get your students excited about the science we have learned and have yet to learn about the Saturnian system.

• NEW! Activity Collection: Jewel of the Solar System – Explore Saturn and the Cassini mission with this eight-part series of activities targeting after-school settings.
0. Jewel of the Solar System Activity Guide
1. What Do I See When I Picture Saturn?
2. Where Are We in the Solar System?
3. Discovering Saturn: The Real "Lord of the Rings"
4. Saturn's Fascinating Features
5. My Spacecraft to Saturn
6. All About Titan and Huygens Probe
7. Drop Zone! Design and Test a Probe
8. Celebrating Saturn and Cassini
• Lesson: Flying By Saturn's Moon Enceladus – Teach students about Saturn's scientifically intriguing moon Enceladus and investigate its fascinating features, including its ocean and plumes, using math.
• Video Lesson: Bouncing Radio Waves Off Titan's Lakes – Learn about one way we study Titan in this educational video.
• Problem Set: Pi in the Sky – Have older students use mathematics to calculate Cassini's fuel reserves.
• Problem Set: Pi in the Sky 4 – Students can also calculate the date of the spacecraft's Grand Finale dive into Saturn.
• Download a poster of Saturn and the Cassini mission timeline.
• Download these Cassini retro posters.

Explore More

• Cassini Lessons for Educators
• Cassini Activities for Students
• Cassini Mission Website
• Cassini Grand Finale Toolkit
• Cassini Mission Overview
• Interactive Cassini Mission Timeline
• Video: NASA VR: Cassini's Grand Finale (360 Video)
• Slideshow for Students (includes a free poster!): 8 Real World Space Facts About Saturn's Moon Enceladus
• Slideshow for Students (includes a free poster!): Ocean Worlds
• Explore the Cassini Spacecraft in 3-D
• The Saturn System Through the Eyes of Cassini (e-book)

TAGS: Saturn, Titan, Cassini, Grand Finale, Teachable Moments, Kepler's Laws, K-12, Lessons,

• 

  ABOUT THE AUTHOR

  Ota Lutz, STEM Elementary and Secondary Education Specialist, NASA/JPL Edu

  Ota Lutz is a STEM elementary and secondary education specialist 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.

Why It’s Important

These images of Jupiter, Saturn, Uranus and Neptune (clockwise from top) were taken by Voyager 1 and 2 as the spacecraft journeyed through the solar system. See a gallery of images that Voyager took on the Voyager website. Credit: NASA/JPL-Caltech

In addition to shaping our understanding of the outer planets, the Voyager spacecraft are helping us learn more about the space beyond the planets – the outer region of our solar system. After completing their “grand tour” of the outer planets, the Voyagers continued on an extended mission to the outer solar system. They are now more than 10 billion miles from Earth, exploring the boundary region between our planetary system and what’s called interstellar space.

The beginning of interstellar space is where the constant flow of material from the Sun and its magnetic field stop influencing the surroundings. Most of the Sun’s influence is contained within the heliosphere, a bubble created by the Sun and limited by forces in interstellar space. (Note that the heliosphere doesn’t actually look like a sphere when it travels through space; it’s more of a blunt sphere with a tail.) The outer edge of the heliosphere, before interstellar space, is a boundary region called the heliopause. The heliopause is the outermost boundary of the solar wind, a stream of electrically charged atoms, composed primarily of ionized hydrogen, that stream outward from the Sun. Our planetary system lies inside the bubble of the heliosphere, bordered by the heliopause and surrounded by interstellar space.

Though we’ve learned a lot about the heliopause thanks to the Voyager spacecraft, its thickness and variation are still key unanswered questions in space physics. As the Voyagers continue their journey, scientists hope to learn more about the location and properties of the heliopause.

From their unique vantage points – Voyager 1 in the northern hemisphere and Voyager 2 in the southern hemisphere – the spacecraft have already detected differences and asymmetries in the solar wind termination shock, where the wind abruptly slows as it approaches the heliopause. For example, Voyager 2 crossed the termination shock at a distance of about 83.7 AU in the southern hemisphere. (One AU, or astronomical unit, is equal to 150 kilometers (93 million miles), the distance between Earth and the Sun.) That’s about 10 AU closer to the Sun than where Voyager 1 crossed the shock in the north. As shown in this diagram, Voyager 1 traveled through the compressed “nose” of the termination shock and Voyager 2 is expected to travel through the flank of the termination shock.

With four remaining powered instruments on Voyager 1 and five remaining powered instruments on Voyager 2, the two spacecraft continue to collect science data comparing their two distinct locations at the far reaches of the solar system.

In August 2012, Voyager 1 detected a dramatic increase in galactic cosmic rays (as shown in this animated chart). The increase, which has continued to the current peak, was associated with the spacecraft's crossing into interstellar space. Credit: NASA/JPL-Caltech

Since it launched from Earth in 1977, Voyager 1 has been using an instrument to measure high-energy, dangerous particles traveling through space called galactic cosmic rays. While studying the interaction between the bubble of the heliosphere and interstellar space, Voyager 1 revealed that the heliosphere is functioning as a radiation shield, protecting our planetary system from most of these galactic cosmic rays. So in August 2012, when Voyager 1 detected a dramatic increase in the rays, which has continued to the current peak, it was associated with the spacecraft’s crossing into interstellar space.

Meanwhile, Voyager 2 ­­– which is still in the heliosheath, the outermost layer of the heliosphere between the shock and the heliopause ­– is using its solar wind instrument to measure the directional change of solar wind particles there. Within the next few years, Voyager 2 is also expected to cross into interstellar space, providing us with even more detailed data about this mysterious region.

In another 10 years, we expect one or both Voyagers to cruise outward into a more pristine region of interstellar space, returning data to inform our hypotheses about the concentration of galactic particles and the characteristics of interstellar wind.

Even with 40 years of space flight behind them, the Voyagers are expected to continue returning valuable data until about 2025. Communications will be maintained until the spacecraft’s nuclear power sources can no longer supply enough electrical energy to power critical functions. Until then, there’s still much to learn about the boundary of our heliosphere and what lies beyond in the space between the stars.

Teach It

Use these standards-aligned lessons and related activities to get students doing math and science with a real-world (and space!) connection.

• Hear Here - Students use the mathematical constant pi and information about the current location of Voyager 1 to learn about the faint data-filled signal being returned to Earth.
• Solar System Bead Activity – Students calculate and construct a scale model of solar system distances using beads and string.
• Catching a Whisper from Space – Students kinesthetically model the mathematics of how NASA communicates with spacecraft.

Explore More

• Voyager Mission
• Voyager Images
• Voyager Golden Record
• The Sounds of Interstellar Space
• Voyager Senses Sun's Tsunami Wave in Interstellar Medium
• Commemorative Voyager Posters

TAGS: Voyager, Farthest, Golden Record, STEM, Teachable Moments, Science, Engineering, Solar System, Interstellar Space, Heliopause, Heliosphere, Heliosheath, Termination Shock, Stars, Heliophysics

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  ABOUT THE AUTHOR

  Ota Lutz, STEM Elementary and Secondary Education Specialist, NASA/JPL Edu

  Ota Lutz is a STEM elementary and secondary education specialist 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.

The sun's outer atmosphere (corona) and thin lower atmosphere (chromosphere) can be seen streaming out from the covered disk of the sun during a solar eclipse on March 20, 2015. Credit: S. Habbal, M. Druckmüller and P. Aniol

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.

Scientists measure incoming solar radiation on Earth, also known as insolation, to better understand Earth’s radiation budget – the energy emitted, reflected and absorbed by Earth. Just as clouds block sunlight and reduce insolation, the eclipse will block sunlight, providing a great opportunity to study how increased cloud cover can impact weather and climate. (Learn more about insolation during the 2017 eclipse here.)

Citizen scientists can get involved in collecting data and participating in the scientific process, too, through NASA’s Global Learning and Observations to Benefit the Environment, or GLOBE, program. During the eclipse, citizen scientists in the path of totality and in partial eclipse areas can measure 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.

You can learn more about the many ways scientists are using the eclipse to improve their understanding of Earth, the Moon and the Sun here.

How to View It

Important! Do not look directly at the Sun or view the partial eclipse without certified eclipse glasses or a solar filter. For more information on safe eclipse viewing, visit the NASA Eclipse website.

When following proper safety guidelines, witnessing an eclipse is an unparalleled experience. Many “eclipse chasers” have been known to travel the world to see total eclipses.

The start time of the partial eclipse, when the edge of the Moon first crosses in front of the disk of the Sun, will depend on your location. You can click on your location in this interactive eclipse map to create a pin, which will show you the start and end time for the eclipse in Universal Time. (To convert from Universal Time to your local time, subtract four hours for EDT, five hours for CDT, six hours for MDT, or seven hours for PDT.) Clicking on your location pin will also show you the percent of Sun that will be eclipsed in your area if you’re outside the path of totality.

If you are inside the approximately 70-mile-wide strip known as the path of totality, where the shadow of the Moon, or umbra, will fall on Earth, the total eclipse will be visible starting about an hour to 1.5 hours after the partial eclipse begins.

Only when the eclipse is at totality – and the viewer is in the path of totality – can eclipse glasses be removed. Look at the eclipse for anywhere from a few seconds to more than 2.5 minutes to see the Sun’s corona and chromosphere, as well as the darkened near side of the Moon facing Earth. As before, your viewing location during the eclipse will determine how long you can see the eclipse in totality.

After totality ends, a partial eclipse will continue for an hour to 1.5 hours, ending when the edge of the Moon moves off of the disk of the Sun. Remember, wear eclipse glasses or use a pinhole camera for the entirety of the partial eclipse. Do not directly view the partial eclipse.

Make a Pinhole Camera

Find out how to make your very own pinhole camera to safely view the eclipse in action.

› Get started!

To get an idea of what the eclipse will look like from your location and explore the positions of the Moon, Sun and Earth throughout the eclipse, see this interactive simulation.

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 interactive eclipse map.

NASA Television will host a live broadcast beginning at 9 a.m. PDT on Aug. 21 showing the path of totality and featuring views from agency research aircraft, high-altitude balloons, satellites and specially-modified telescopes. Find out how and where to watch, here. 

Teach It

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

• Epic Eclipse – Students use the mathematical constant pi to approximate the area of land covered by the Moon’s shadow during the eclipse.
• Pinhole Camera – Learn how to make your very own pinhole camera to safely see a solar eclipse in action from anywhere the eclipse is visible, partial or full!
• Moon Phases - Students learn about the phases of the Moon by acting them out. In 30 minutes, they will act out one complete, 30-day, Moon cycle.
• NEW! Measuring Solar Energy During an Eclipse – Students use mobile devices to measure the impact a solar eclipse has on the energy received at Earth’s surface.
• NEW! Modeling the Earth-Moon System – Students learn about scale models and distance by creating a classroom-size Earth-Moon system.
• NASA GLOBE Observer – Students can become citizen scientists and collect data for NASA’s GLOBE Program using this app available for iOS and Android devices (eclipse update available starting August 18, 2017).

Explore More

• NASA TV Eclipse 2017 broadcast info
• NASA 2017 Eclipse website
• NASA Eyes Eclipse 2017 Interactive
• Interactive Eclipse Map
• NASA Eclipse website (for info about other eclipses)
• Eclipse Safety
• American Astronomical Society website (for info on reputable vendors of solar viewers and filters)
• Earth’s Radiation Budget

TAGS: Eclipse, Solar Eclipse, Science, Pinhole Camera, K-12, Students, Educators

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  ABOUT THE AUTHOR

  Lyle Tavernier, Educational Technology Specialist, NASA/JPL Edu

  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.