Next time you're marveling at the fact that Spirit and Opportunity have been roving Mars for over six years now, ponder this: the two Voyager spacecraft have been hurtling through our solar system for nearly 33 years. Today, Voyager 1 hits a mission milestone of operating continuously for 12,000 days. The spacecraft launched on September 5, 1977, while Jimmy Carter was president, and has now traveled 14 billion miles.
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Voyager 1 made its closest approach to Jupiter in March 1979, coming to within about 217,000 miles of the planet's center and making detailed observations of Jupiter's moons. During its flyby of Saturn in November 1980, the spacecraft's cameras and remote sensing instruments revealed stunning images and information about Saturn's rings and atmosphere, as well as its giant moon Titan. In early 1990, Voyager 1 captured the now-famous image known as "Pale Blue Dot." As the spacecraft was on its way out of the solar system, astronomer Carl Sagan commanded it to turn its camera and take a picture of planet Earth dangling in the vastness of space.By early 2005, Voyager 1 was about 94 times farther from the Sun than Earth is. Within the next five years, the spacecraft will enter interstellar space, where it will study the boundaries of the solar system, including the Kuiper Belt. Long-life nuclear batteries are expected to power Voyager 1 until at least 2020, when it will be more than 13 billion miles from Earth.
Voyager 2, which completed observations of Uranus and Neptune in addition to Saturn and Jupiter, reached its 12,000-day milestone on June 28. The two space probes are the most distant human-made objects in the universe.