Voyager 1 was launched on September 5, 1977, and is now the farthest man-made object from Earth. As of February 2018, it is over 141 AU from the Sun (1 AU is the average distance between the Earth and Sun), or about 13.7 billion miles (22.1 billion kilometers). It will take Voyager 1 another 40,000 years to come within 1 light-year of any other star.
The spacecraft is currently traveling at a speed of about 38,000 mph (17 kilometers per second) relative to the Sun. In December 2004, Voyager 1 became the first human-made object to enter interstellar space as it crossed the heliopause—the point at which the solar wind slows down and becomes dominated by interstellar wind.
Since its launch over 40 years ago, Voyager 1 has made numerous discoveries about our Solar System and beyond. For example, in 1980 it discovered that Jupiter’s moon Io was volcanically active; in 1986 it provided evidence that Saturn’s moon Enceladus had liquid water beneath its surface; and in 2012 it detected an electric circuit between Saturn’s upper atmosphere and its magnetosphere—a finding that may help explain how energy is transferred from Saturn’s interior to power its aurorae.
In addition to these scientific accomplishments, Voyager 1 also holds several records: it is the most distant human-made object from Earth; it has traveled the furthest into interstellar space; and its twin spacecraft, Voyager 2, is the only other spacecraft to have visited all four giant planets (Jupiter, Saturn, Uranus, Neptune).