The Voyager Mission

One of NASA's most successful missions, Voyager 1 and 2, was launched less than a month apart. Voyager 1 was launched on 5 Sept 1977, and Voyager 2 was launched on 20 Aug 1977.


Although Voyager 2 was launched earlier than its twin, Voyager 1 crossed Voyager 2 on Dec. 15 1977, due to its faster route.

Image credit- https://www.pbs.org


As it approached Jupiter in April 1978, the spacecraft began imaging the planet from 165 million miles away. Images sent back by January 1979 indicated that the atmosphere of Jupiter was more turbulent than during the Pioneer flybys in 1973-1974. Voyager 1 took a picture every 96 seconds for 100 hours beginning Jan. 30 1979, to create a colour time-lapse movie of Jupiter's 10 rotations.


Early in March 1979, the spacecraft discovered a thin ring circling Jupiter (less than 19 miles or 30 kilometres thick) after crossing into the Jovian moon system. The closest approach of Voyager 1 to Jupiter occurred at 12:05 UT on March 5 1979, at a distance of about 174,000 miles. Following this, it encountered several of Jupiter's moons, including Amalthea (260,100 miles away), Europa (45,830 miles away), Ganymede (71,280 miles away), and Callisto (78,540 miles away), in that order, returning spectacular images of their terrain and opening up whole new worlds for planetary scientists to explore.


Images of Io showed a bizarre yellow, orange, and brown world with at least eight active volcanoes spewing material into space, making it one of the most geologically active planetary bodies in the solar system. Volcanic plumes from Io may be responsible for the sulfur and oxygen in Jovian space due to their sulfur dioxide content.

Image credit- https://nssdc.gsfc.nasa.gov


As part of its preparation for its meeting with Saturn, Voyager 1 completed an initial course correction following its encounter with Jupiter on April 9 1979.

A second correction on October 10 1979, made sure that the spacecraft wouldn't hit Saturn's moon Titan. Its flyby of Saturn in November 1979 was as exciting as its previous encounter. During Voyager 1, scientists discovered five new moons, thousands of bands within a ring system, transient clouds of tiny particles known as "spokes" in the B-ring, a new ring (the G-ring), and satellites that shepherd the F-rings.

The spacecraft photographed Titan, Mimas, Enceladus, Tethys, Dione, and Rhea during its flyby of Saturn. According to incoming data, all the moons appeared to be composed mostly of water ice. The most interesting target was Titan, which Voyager 1 passed at 05:41 UT on Nov. 12, 1979.


The surface was hidden by a thick atmosphere in the images. The spacecraft found that 90% of the moon's atmosphere is nitrogen. At Titan's surface, the pressure was 1.6 atmospheres, and the temperature was minus 292 degrees Fahrenheit (minus 180 degrees Celsius). Atmospheric data indicate that liquid might exist on Titan's surface for the first time. Titan might also be able to support prebiotic chemical reactions due to the presence of nitrogen, methane, and more complex hydrocarbons.

In 1980, Voyager 1 came closest to Saturn at 23:46 UT, at a range of 78,290 miles (126,000 kilometres). After its encounter with Saturn, Voyager 1 left the solar system at about 3.5 AU (325 million miles or 523 million kilometres) per year, 35 degrees to the north of the ecliptic plane and in the direction of the Sun as it moves with nearby stars. Uranus and Neptune were not targeted because of Titan's specific requirements.


Voyager 1 captured about 60 images of the Sun and planets on Feb 14 1990, the first "portrait" of our solar system seen from space. As the Voyager spacecraft approached 40 AU from the Sun (3.7 billion miles or 6 billion kilometres), a mosaic of those images developed into the famous "Pale Blue Dot" image made famous by Cornell University professor and Voyager team member Carl Sagan (1934-1996).

The image has also been referred to as the "Solar System Family Portrait", even though Mercury and Mars are not visible in the picture. Mercury was too close to the Sun to be se