On November 12th, it turned 35 years old as the NASA Voyager-1 spacecraft flew near Saturn. Between his span and the span of his twin - Voyager 2 next year, we got the best image of the Saturn system for more than 20 years. But what do we know about Voyager 1?
Everyone knows that there were a total of five missions that visited Saturn. Pioneer 11 made a quick pass past the planet and its satellites in 1979, followed by Voyager 1 and Voyager 2 in 1980 and 1981, respectively. The spacecraft used the rare structure of the planets, which allowed them to study Jupiter, Saturn, Uranus and Neptune.
Then there was a long break until Cassini arrived at the planet in 1997. His research, which lasted until 2004, cannot be re-evaluated, since it was a valuable long-term mission to the Saturn system. People working on the Cassini mission observed changes in the atmosphere of Saturn and its satellites, the movement of the planet around the Sun, and received different data on the temperature in the northern and southern hemispheres. Travel Voyager-1, in contrast, allowed us to get the first images of the planet and its satellites, made close-up.
While Saturn's rings are visible even through a small telescope, it takes a spacecraft to view them in fine detail. Pioneer 11 passed Saturn in 1979 and found that the F-ring looks more fragmented than expected. Later, NASA announced that the ring was full of “bunches” and “peculiar kinks”. The ring was studied in detail by the Voyager-1 apparatus when it flew past Saturn in 1980. But it will take several more decades before scientists understand what is happening. Cassini became the first long-term mission to Saturn and discovered that the orbits Prometheus and Pandora - two small satellites - cause visible changes in the shape of the F-ring.
Enceladus is one of the most impressive satellites of the solar system due to geysers breaking into space. Cassini first discovered these emissions 10 years ago and only recently passed through these emissions to take a sample of the material. Some scientists believe that these geysers filled with water may provide evidence of life beneath the ice.
In addition, back in 1980, a photograph of Enceladus (left) showed that the surface looked relatively young with few craters and lots of ice. Even today, we know little about what processes are under the surface.
One of the pleasant surprises of such spans is the discovery of something new and unexpected. Voyager 1 spotted this tiny satellite, which was temporarily dubbed 1980S28. Today we know this satellite as Atlas, which in Greek mythology was the son of Iapetus (another satellite of Saturn), as well as Titan (another satellite).
Voyager 1 flew too far to see the Atlas satellite features. But thanks to the later flight of the Cassini spacecraft, we now know about the characteristic equatorial region, which is not found in any other satellite of the Solar system.
Not many changes on the surface Rei. It seems that a part of its surface is very old and probably dates back to the formation of the Solar System 4, 5 billion years ago. Voyager 1 was able to capture these ancient crater areas, and also saw spots that seem younger. Then scientists suggested that these white edges of craters contain volatile elements with a low boiling point or may be formed by ice.
In 2006, Cassini showed that on the surface of Rei there are cracks that form canyons, some of which reach several hundred meters in depth. On the walls of these faults is a dark material, under which one can see white water ice. This suggests that Rhea may have been geologically active in the past.
This is not a space station - it is a satellite! One of the most amazing discoveries that Voyager-1 made is a satellite resembling the “Star of Death” from Star Wars. This image clearly shows the giant crater on Mimas. Something big collided with it in the distant past, putting the very existence of the satellite on the edge.
Mimas was under the scrutiny of the Cassini spacecraft. Cassini revealed that Mimas is full of impact craters. NASA suggests that if the satellite were not located so close to Saturn, it would have even more craters. Curiously, some of the craters located in the southern region seem to be polished. Scientists believe that the likely cause is emissions from Enceladus.
Tethys was known to the astronomer before the Voyager-1 and Voyager-2 spans, but it was thanks to the latter that astronomers got a better idea of its surface. This image, taken by the Voyager spacecraft, shows a huge crater, as well as a large abyss.
Thanks to Cassini's data, scientists had the opportunity to compare it with other similar satellites: Dione and Rey. Tethia releases fewer craters. Scientists suggest that due to the closer location of the satellite to the parent planet, Tethys heats up more, and the collisions are not so destructive.
Epimetheus is a strange satellite, since he and Janus have almost identical orbits. Scientists were quite amazed, as they believed that over time, these satellites had to collide.
It turns out that Janus and Epimetheus periodically change places, becoming closer and further from Saturn.
When Voyager 1 passed next to satellite Titan, its surface was secret. The satellite is surrounded by a dense orange haze that completely covers the surface under it. You must understand how it looked strange, because at that time, astronomers did not know about the existence of a satellite with its own atmosphere. It turned out that the satellite is larger than the moon, they have their own weather and atmosphere.
The powerful Cassini radar scanned the dense atmosphere many times when it visited the Saturn system in 2004. A small Huygens descent vehicle descended to the surface and collected data in a few hours. It was then that astronomers learned that Titan has hydrocarbon lakes and seas, consisting of methane and ethane. The satellite also has a water cycle, like the Earth. There may even be volcanoes. All this makes Titan a prime candidate for future research into the solar system.
Clouds of Saturn
Despite the fact that the system of Saturn was visited by many spacecraft, there are still many unsolved things related to the structure of the atmosphere of Saturn. This complex process, which is due to the internal heat of Saturn and heating from the sun.
Scientists seek to send more long-term missions to study the gas giants in order to understand what is happening in their depths. Cassini will gain superficial knowledge of this when he plunges into the atmosphere of Saturn in 2017, until terrible pressure crushes him.