This illustration shows the position of NASA's Voyager 1 and Voyager 2 probes, outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto.

In the News

The Voyager 2 spacecraft, launched in 1977, has reached interstellar space, a region beyond the heliosphere – the protective bubble of particles and magnetic fields created by the Sun – where the only other human-made object is its twin, Voyager 1.

The achievement means new opportunities for scientists to study this mysterious region. And for educators, it’s a chance to get students exploring the scale and anatomy of our solar system, plus the engineering and math required for such an epic journey.

How They Did It

Launched just 16 days apart, Voyager 1 and Voyager 2 were designed to take advantage of a rare alignment of the outer planets that only occurs once every 176 years. Their trajectory took them by the outer planets, where they captured never-before-seen images. They were also able to steal a little momentum from Jupiter and Saturn that helped send them on a path toward interstellar space. This “gravity assist” gave the spacecraft a velocity boost without expending any fuel. Though both spacecraft were destined for interstellar space, they followed slightly different trajectories.

Illustration of the trajectories of Voyager 1 and 2

An illustration of the trajectories of Voyager 1 and Voyager 2. Image credit: NASA/JPL-Caltech | + Expand image

Voyager 1 followed a path that enabled it to fly by Jupiter in 1979, discovering the gas giant’s rings. It continued on for a 1980 close encounter with Saturn’s moon Titan before a gravity assist from Saturn hurled it above the plane of the solar system and out toward interstellar space. After Voyager 2 visited Jupiter in 1979 and Saturn in 1981, it continued on to encounter Uranus in 1986, where it obtained another assist. Its last planetary visit before heading out of the solar system was Neptune in 1989, where the gas giant’s gravity sent the probe in a southward direction toward interstellar space. Since the end of its prime mission at Neptune, Voyager 2 has been using its onboard instruments to continue sensing the environment around it, communicating data back to scientists on Earth. It was this data that scientists used to determine Voyager 2 had entered interstellar space.

How We Know

Interstellar space, the region between the stars, is beyond the influence of the solar wind, charged particles emanating from the Sun, and before the influence of the stellar wind of another star. One hint that Voyager 2 was nearing interstellar space came in late August when the Cosmic Ray Subsystem, an instrument that measures cosmic rays coming from the Sun and galactic cosmic rays coming from outside our solar system, measured an increase in galactic cosmic rays hitting the spacecraft. Then on November 5, the instrument detected a sharp decrease in high energy particles from the Sun. That downward trend continued over the following weeks.

The data from the cosmic ray instrument provided strong evidence that Voyager 2 had entered interstellar space because its twin had returned similar data when it crossed the boundary of the heliosheath. But the most compelling evidence came from its Plasma Science Experiment – an instrument that had stopped working on Voyager 1 in 1980. Until recently, the space surrounding Voyager 2 was filled mostly with plasma flowing out from our Sun. This outflow, called the solar wind, creates a bubble, the heliosphere, that envelopes all the planets in our solar system. Voyager 2’s Plasma Science Experiment can detect the speed, density, temperature, pressure and flux of that solar wind. On the same day that the spacecraft’s cosmic ray instrument detected a steep decline in the number of solar energetic particles, the plasma science instrument observed a decline in the speed of the solar wind. Since that date, the plasma instrument has observed no solar wind flow in the environment around Voyager 2, which makes mission scientists confident the probe has entered interstellar space.

graph showing data from the cosmic ray and plasma science instruments on Voyager 2

This animated graph shows data returned from Voyager 2's cosmic ray and plasma science instruments, which provided the evidence that the spacecraft had entered interstellar space. Image credit: NASA/JPL-Caltech/GSFC | + Expand image

Though the spacecraft have left the heliosphere, Voyager 1 and Voyager 2 have not yet left the solar system, and won't be leaving anytime soon. The boundary of the solar system is considered to be beyond the outer edge of the Oort Cloud, a collection of small objects that are still under the influence of the Sun's gravity. The width of the Oort Cloud is not known precisely, but it is estimated to begin at about 1,000 astronomical units from the Sun and extend to about 100,000 AU. (One astronomical unit, or AU, is the distance from the Sun to Earth.) It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud and possibly 30,000 years to fly beyond it. By that time, both Voyager spacecraft will be completely out of the hydrazine fuel used to point them toward Earth (to send and receive data) and their power sources will have decayed beyond their usable lifetime.

Why It’s Important

Since the Voyager spacecraft launched more than 40 years ago, no other NASA missions have encountered as many planets (some of which had never been visited) and continued making science observations from such great distances. Other spacecraft, such as New Horizons and Pioneer 10 and 11, will eventually make it to interstellar space, but we will have no data from them to confirm their arrival or explore the region because their instruments already have or will have shut off by then.

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Interstellar space is a region that’s still mysterious because until 2012, when Voyager 1 arrived there, no spacecraft had visited it. Now, data from Voyager 2 will help add to scientists’ growing understanding of the region. Scientists are hoping to continue using Voyager 2’s plasma science instrument to study the properties of the ionized gases, or plasma, that exist in the interstellar medium by making direct measurements of the plasma density and temperature. This new data may shed more light on the evolution of our solar neighborhood and will most certainly provide a window into the exciting unexplored region of interstellar space, improving our understanding of space and our place in it.

As power wanes on Voyager 2, scientists will have to make tough choices about which instruments to keep turned on. Further complicating the situation is the freezing cold temperature at which the spacecraft is currently operating – perilously close to the freezing point of its hydrazine fuel. But for as long as both Voyager spacecraft are able to maintain power and communication, we will continue to learn about the uncharted territory of interstellar space.

Teach It

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

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TAGS: Teachers, Educators, Science, Engineering, Technology, Solar System, Voyager, Spacecraft, Educator Resources, Lessons, Activities

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Illustration of InSight landing on Mars

Tom Hoffman, InSight Project Manager, NASA JPL, left, and Sue Smrekar, InSight deputy principal investigator, NASA JPL, react after receiving confirmation InSight is safe on the surface of Mars

This is the first image taken by NASA's InSight lander on the surface of Mars.

The Instrument Deployment Camera (IDC), located on the robotic arm of NASA's InSight lander, took this picture of the Martian surface on Nov. 26

UPDATE: Nov. 27, 2018 – The InSight spacecraft successfully touched down on Mars just before noon on Nov. 26, 2018, marking the eighth time NASA has succeeded in landing a spacecraft on the Red Planet. This story has been updated to reflect the current mission status. For more mission updates, follow along on the InSight Mission Blog, JPL News, as well as Facebook and Twitter (@NASAInSight, @NASAJPL and @NASA).


NASA's newest Mars mission, the InSight lander, touched down on the Red Planet just before noon PST on Nov. 26. But there's more work ahead before the mission can get a look into the inner workings of Mars. Get your classroom ready to partake in all the excitement of NASA’s InSight mission with this educator game plan. We’ve got everything you need to engage students in NASA's ongoing exploration of Mars!

Day Before Landing

Landing Day (Nov. 26)

Next Day

  • Review the Teachable Moment to find out what needs to happen before InSight’s science operations can begin. Then create an instructional plan with these lessons, activities and resources that get students engaged in the science and engineering behind the mission.
  • Check out InSight’s first images from Mars, here. (This is also where you can find raw images from InSight throughout the life of the mission.)

Over the Next Month


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Follow Along

Resources and Activities

Feature Stories and Podcasts

Websites and Interactives

TAGS: InSight, Mars Landing, Educators, K-12, Elementary School, Middle School, High School, Lessons and Activities, Educator Resources, Mars

  • NASA/JPL Edu
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Update – Sept. 13, 2018: Due to the number of requests we have received, this bulletin board registration is now closed. In the event more materials become available, an update will be posted here. All materials are also available to download at the links below.


Launch back into STEM with these back-to-school resources from NASA all about hurricanes, clouds, weather, Earth science – and the satellites that study them. For a limited time, the Educator Resource Center at NASA's Jet Propulsion Laboratory is offering free bulletin-board materials to educators for display in classrooms or other educational settings.

Register today to receive free materials mailed directly to you or download them at the links below.

Out of stock

  • Bulletin board mailers are limited to teachers at U.S.-based institutions.
  • Available while supplies last.
  • Requests will be fulfilled in the order they are received.

Download bulletin board materials:

Visit our educator resources page for more downloads and online resources.

TAGS: Bulletin Board, Educator Resources, Materials, Educator Resource Center, Downloads, Posters

  • NASA/JPL Edu
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Update – Sept. 20, 2017: Due to the number of requests we have received, this bulletin board registration is now closed. In the event more materials become available, an update will be posted here. All materials are also available to download at the links below. 


This year has been full of exciting discoveries at NASA as we learn more about our solar system as well as star systems light years away.

Want a cool way to share these missions and discoveries with your classroom? Sign up online to receive the latest classroom bulletin board set from the Educator Resource Center at NASA’s Jet Propulsion Laboratory.

Note:

  • Bulletin board mailers are limited to teachers at U.S.-based institutions.
  • Available while supplies last.
  • Requests will be fulfilled in the order they are received.

Here’s what’s included:


Exoplanet Space Tourism Posters

Exoplanet Space Tourism Posters

NASA’s Kepler space telescope, which has already discovered more than 1,000 planets beyond our solar system, continues to identify more and more of these so-called exoplanets – some of which have features similar to Earth. (Learn more about these worlds on NASA's Exoplanet Exploration website.) This popular poster set imagines what life would be like on these distant worlds.

Note: The bulletin board materials will include a small sample of the full set, which can be downloaded here.


Reading, Writing and Rings Activities

Reading, Writing and Rings

Closer to home, September 15 will mark the end of the Cassini mission, which has spent nearly 13 years orbiting the ringed giant Saturn. Images and science from Cassini have shaped our understanding of Saturn and its mysterious moons, and continue to provide wonder to students. This collection of activities will get students using reading and writing to explore the Cassini mission’s science at Saturn.

Find out more about the Cassini mission and its Grand Finale on Sept. 15, 2017.


Saturn Postcards

Saturn Postcards

Take in some of Cassini’s best views of Saturn with these NASA postcards featuring images from the mission!

Explore more images from the Cassini mission at Saturn.


Visit our educator resources page for more downloads and online resources.

TAGS: materials, educator resources, educator resource center, classroom resources, bulletin board, teaching materials

  • NASA/JPL Edu
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