Voyager program

The Voyager program is an American scientific program that employs two interstellar probes, Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment to explore the two gas giants Jupiter and Saturn and potentially also the ice giants, Uranus and Neptune—to fly near them while collecting data for transmission back to Earth. After Voyager 1 successfully completed its flyby of Saturn and its moon Titan, it was decided that Voyager 2 would continue on its pre-planned trajectory to fly by Uranus and Neptune. After the planetary flybys were complete, decisions were made to keep the probes in operation to explore interstellar space and the outer regions of the Solar System. On 25 August 2012, data from Voyager 1 indicated that it had entered interstellar space. On 5 November 2019, data from Voyager 2 indicated that it also had entered interstellar space. On 4 November 2019, scientists reported that on 5 November 2018, the Voyager 2 probe had officially reached the interstellar medium (ISM), a region of outer space beyond the influence of the solar wind, as did Voyager 1 in 2012. In August 2018, NASA confirmed, based on results by the New Horizons spacecraft, the existence of a "hydrogen wall" at the outer edges of the Solar System that was first detected in 1992 by the two Voyager spacecraft. As of 2026, both Voyagers are still in operation beyond the outer boundary of the heliosphere in interstellar space. As of 2024, Voyager 1 was moving with a velocity of 61,000 kilometers per hour (38,000 mph), or 17 km/s, (10.5 miles/second) relative to the Sun, and was 24.5 billion kilometers (164 AU) from the Sun. At the same time, Voyager 2 was moving with a velocity of 55,000 kilometers per hour (34,000 mph),...