(ORDO NEWS) — Recent calculations have shown that the orbit of Titan, the satellite of Saturn, is expanding, which means that the moon of the gas giant is getting farther and farther away from the planet – moving away from it at a speed of about 100 times faster than expected.
Studies show that Titan formed much closer to Saturn, but later migrated to its current distance of 1.2 million kilometers over a period of 4.5 billion years.
The results of the new study are described in an article published in the journal Nature Astronomy on June 8. By earthly standards, the moon of Saturn’s Titan is a strange place. The size of the planet Mercury, Titanium is in a dense atmosphere (the only such satellite in the solar system) and is covered by rivers and seas of liquid hydrocarbons such as methane and ethane. Below them is a thick crust of water ice, under which the existence of a water ocean and even living forms is possible.
To understand the basics of orbital migration, we can take a look at our own moon. The Earth’s moon exerts a slight gravitational pull on the planet at the moment it rotates. This is what causes the tides: the rhythmic jerks of the Moon cause the oceans of the Earth to “shake” from side to side.
Friction processes inside the Earth transform part of this energy into heat, distorting the Earth’s gravitational field, so that it pulls the Moon forward in its orbit. This leads to the fact that the Moon receives energy and gradually moves away from the Earth at a speed of about 3.8 centimeters per year. This process is so gradual that scientists are sure that the Earth will not lose its satellite for at least six billion years.
Titanium has a similar effect on Saturn, but the friction processes inside Saturn are usually considered weaker than inside the Earth. This is possible due to the gaseous composition of Saturn. Standard theories predict that because of its distance from Saturn, Titan must migrate at a very low speed of no more than 0.1 centimeter per year. But new results contradict this forecast.
Two groups of researchers used different methods to measure the orbit of Titan over 10 years. One method, called astrometry, made it possible to obtain accurate measurements of the position of Titan relative to background stars in the images obtained by the Cassini spacecraft. Another technique, radiometry, measured the speed of the Cassini, because it was influenced by the gravitational influence of Titan.
The new results are also consistent with the theory proposed in 2016 by Professor Fuller, who predicted that the Titan’s migration rate would be much faster than the assumed standard tidal theories. His theory notes that Titan is expected to gravitationally compress Saturn at a certain frequency, which causes the planet to oscillate violently, just as your legs are swinging on a swing and swing them even more.
This tidal process is called resonance blocking. Fuller suggested that Saturn’s high vibrational amplitude would dissipate a lot of energy, which in turn would cause Titan to migrate outward from the planet at a much faster rate than previously thought. Indeed, both observations showed that Titan migrates from Saturn at a speed of 11 centimeters per year, more than 100 times faster than previous theories predicted.
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