Image of Voyager spacecraft
Click on image for full size


The rare geometric arrangement of planets Jupiter, Saturn, Uranus, and Neptune in the 1980's made it possible for the Voyager spacecrafts to visit them over a 12 year span instead of the normal 30. They used gravity assists to swing from one planet to the next, conserving fuel.

Voyager 2 was launched on Aug. 20, 1977, followed by Voyager 1 on Sep. 5. Both encountered Jupiter in 1979, returning photographs and information on its many moons. Scientists learned that Jupiter's Great Red Spot is really a complex storm, and that Io, one of Jupiter's moons, has active volcanism. These volcanoes are caused by extreme tidal bulges, due to the gravitational "tug of war" of Jupiter and its other moons on Io.

Voyagers 1 and 2 then continued to Saturn, with Voyager 1 arriving in November 1980 and Voyager 2 in August 1981, where they studied the true composition of Titan's atmosphere, believed to be similar to Earth's ancient environment. They also learned that Saturn's rings formed from particles broken off its moons by comets and meteors.

Voyager 2 then headed for Uranus and Neptune. It gave us our first close-range look at the two planets, finding an unusually shaped magnetic field around Uranus caused by the tilt of that planet's axis of rotation. Voyager 2 later learned that the strongest winds in our solar system exist on Neptune, and that Neptune's Great Dark Spot is really a hole in its atmosphere.

The Voyager missions discovered a total of 21 new moons and returned information that has revolutionized the field of space science. The two spacecrafts have almost reached the boundary of our solar system called the heliopause. Because the Sun is so faint at such a distance, the Voyagers are nuclear powered, using energy released from the decay of plutonium. They will continue transmitting for another 20 years until their nuclear generators no longer supply adequate energy.

Last modified September 26, 2000 by Jennifer Bergman.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

The Great Red Spot of Jupiter

The Great Red Spot is thought to be a hurricane which has been raging on Jupiter for at least 400 years. The connected page shows an image of the Great Red Spot next to Tropical Storm Emily for comparison....more

Radioactive Decay

Some materials are radioactive. They emit radiation. When an atom of a radioactive substance emits radiation, it is transformed to a new type of atom. This process is called radioactive decay. There are...more

Administrator Goldin's Statement on NASA's Fortieth Anniversary

This is Administrator Goldin's address about NASA's 40th anniversary: "Forty years ago, in 1958, the National Aeronautics and Space Administration was created with the boldest and most noble of missions:...more

Missions Possible!

The servicing mission to the Hubble Space Telescope in early March looks to have been a great success. Four weeks after the servicing mission, the Telescope has been declared healthy and fit...and is frankly,...more

Voyager to Take the Lead!

At approximately 5:10 p.m. EST on February 17, 1998, the Voyager 1 spacecraft will become the spacecraft that has traveled farthest away from the planet Earth. For 25 years, Pioneer 10 has been in the...more

Happy Birthday to Voyager!

NASA's Voyager mission is 25 years old and still going strong! Both spacecrafts Voyager 1 (launched September 5, 1977) and Voyager 2 (launched August 20, 1977) continue to travel through space and still...more

Discover Jupiter

Jupiter is the largest planet in our solar system. It is also one of the brighter objects in the night sky. No one knows for sure who discovered Jupiter, but we know the ancient Greeks named him after...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA