Voyager 1 is a space probe launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and interstellar space beyond the Sun's heliosphere. It was launched 16 days after its twin, Voyager 2, but due to a faster trajectory, it overtook Voyager 2 and reached Jupiter and Saturn first. The probe conducted flybys of Jupiter in 1979 and Saturn in 1980, with a close approach to Saturn's moon Titan on November 12, 1980, at a distance of 6,490 km. This flyby was prioritized over a Pluto flyby because Titan was known to have a substantial atmosphere.
Voyager 1 crossed the heliopause and entered interstellar space on August 25, 2012, becoming the first human-made object to do so. NASA officially confirmed this achievement on September 12, 2013. As of May 2025, it is at a distance of 166.40 astronomical units (AU) from Earth, making it the most distant human-made object from Earth. It is moving at a speed of approximately 18 km per second (3.6 AU per year) and is projected to reach a distance of one light day from Earth in November 2026.
The spacecraft is powered by three radioisotope thermoelectric generators (RTGs) that initially produced about 470 watts of electric power. Its extended mission, focused on studying the outer heliosphere and the interstellar medium, is expected to continue returning scientific data until at least 2025, with engineering data potentially being transmitted until 2036. Voyager 1 communicates with Earth via the NASA Deep Space Network using a 3.7-meter high-gain antenna, and signals from the probe take over 22 hours to reach Earth.
The probe carries the Voyager Golden Record, a phonograph record containing sounds and images selected to portray the diversity of life and culture on Earth, intended as a message to any potential extraterrestrial life. In about 40,000 years, Voyager 1 will come within about 1.8 light-years of the star Gliese 445 in the constellation Camelopardalis.
The Voyager 1 spacecraft carries a 12-inch gold-plated copper disk, known as the Voyager Golden Record, which serves as a time capsule of Earth's culture and life. This disk contains a curated collection of sounds and images, including natural sounds like thunder and bird calls, greetings in 55 languages, 90 minutes of music from diverse cultures and eras, and 115 analog-encoded photographs depicting Earth and its inhabitants. The record is protected by a gold-plated aluminum cover that includes diagrams explaining how to play the record, instructions for finding Earth using pulsar maps, and information about the hydrogen atom, the most common element in the universe. Designed to endure for billions of years, the disk was created under the leadership of astronomer Carl Sagan and represents humanity's attempt to communicate a story of our world to any potential extraterrestrial discoverers.