Astronomers found that Titan is removed from Saturn at a speed of 11 inches per year. As reported in Nature Astronomy, uhit’s a hundred times faster than previously thought. The scientists also found that in the past the satellite was much closer to the gas giant, and its current orbit, it migrated over 4.5 billion years.
The removal of satellites from their planets — a fairly common phenomenon, characteristic not only for Titanium. For example, the Moon also escapes from the Earth at a rate of about 3.8 centimeters per year. This effect is gravitational-tidal interactions between the planet and its satellite. When the Moon moves around Earth, its gravity causes the tides, and the oceans formed a tidal wave that is slightly shifted forward with the line connecting the centers of mass of the Earth and moon, due to the rotation of our planet. And since the attraction of the satellite to the near tidal wave stronger than the far, the orbital angular momentum of the heavenly body increases and it moves to a higher orbit.
A similar interaction occurs between Titan and Saturn. However, scientists assumed that it will not be as pronounced due to the gaseous structure of the planet. Standard models predict that Titan should be removed from the gas giant at a speed of not more than 0.1 cm per year, but a new study contradicts this prediction.
Valery Lainey (Valéry Lainey) from the California Institute of technology together with colleagues used two methods to determine the change of the orbit of Titan. In the first case, astronomers have reconstructed the orbit of Cassini during ten encounters with the satellite, made from 2006 to 2016. Tracking, how changing the position of the spacecraft relative to Titan and Saturn, the researchers have obtained indirect evidence about the change in orbit and the moon. In the second case, the group Lainie relied on classical astrometric data. To opredeliti as the increased distance between Titan and Saturn, the researchers used the measurement of the position of Titan relative to the background stars, since 1886.
It was found that the Titanium is removed from Saturn at a speed of 11 inches per year, which is much more expected values. In addition, the authors came to the conclusion that at the time of formation of the moon the distance between it and the gas giant was much less than today, however, due to the gravitational interactions of the satellite with time moved to a higher orbit in the 1.2 million kilometers.
Researchers obtained results are in agreement with the theory proposed by the research group Jim fuller (Jim Fuller) in 2016. The astronomer suggested that resonance capture is a situation where the gravitational influence of the satellite makes Central the planet to oscillate with a certain frequency — could make the Titan faster to get away from Saturn, because the high amplitude leads to loss of more energy.
Recently, scientists were able to build the first geomorphological map of Titan, which shows the lake and the dune field of a celestial body. A key role in the creation of sand dunes on the moon Titan, according to scientists, can play dust devils.