Voyager 1
First Close-Up View of Jupiter from Voyager 1
Time-Lapse Video of Jupiter from Voyager 1
Voyager 1

Voyager 1

Courtesy of NASA

Voyager 1 and Voyager 2 are twin spacecraft, both launched in 1977 on flyby missions to gather data about planets in the outer solar system. Voyager 2 was launched before Voyager 1, but Voyager 1 arrived at Jupiter ahead of Voyager 2. More than 30 years later, these spacecraft continue to transmit data and are the farthest man-made objects from Earth. They are now at the edge of the solar system and will be the first probes to leave the solar system and enter interstellar space.

(Voyager 1) September 5, 1977; (Voyager 2) August 20, 1977

(Voyager 1) March 5, 1979; (Voyager 2) July 9, 1979

End of Mission
Still operating as of 2017, expected to operate until 2025

Conduct close-up studies of Jupiter and Saturn, Saturn's rings, and the larger moons of the two planets.

Voyager 1 identified nine active volcanoes on Io. Voyager 2 also observed eight of the nine volcanoes. Plumes from the volcanoes reach more than 300 kilometers (190 miles) above the surface. The material was being ejected at velocities up to 1.05 kilometers per second (2300 mph). Compare that to the ejecta velocities of one of Earth’s most explosive volcanoes, Mt. Etna, which are 50 meters per second (112 mph). Volcanism on Io is related to tidal action from its interactions with Jupiter and with Europa and Ganymede (two large satellites nearby). Io is constantly being pulled back and forth. This causes tidal bulges of 100 meters (330 feet) on Io’s surface. Typical tidal bulges on Earth resulting from our interactions with the Moon are about one meter (three feet).

Voyager 1 photos of Europa showed a large number of crossing linear features. Scientists at first believed the features might be deep cracks, caused by rifts in the crust or tectonic processes.

Both Voyagers 1 and 2 continue to send back data, providing scientists with valuable observations of the solar system’s edge and interstellar space. Voyager 1 is now the furthest human-made object from the Sun, having surpassed Pioneer 10 on February 17, 1998.