Jupiter tidal forces

Comets are generally considered to be weakly consolidated, and active comets are commonly observed to split into fragments. This is sometimes due to the tidal forces of a close planetary encounter, such as affected comet Shoemaker-Levy when it passed close to Jupiter in 1992 and broke into 21 pieces. More commonly, a comet spontaneously fragments multiple times over its orbit period, without any obvious cause. Disintegrating comets leave trails of small particles in their wakes. These trails are known as meteor streams, and when the Earth passes through such a meteor stream, as it does several times a year, a meteor shower occurs. Meter-sized rocks are known to occur within cometary meteor streams. 

The Roche Urn it was first described by Edouard Roche in 1848. It is the closest distance a body held together by self-gravity can come to a planet without being pulled apart by the planet s tidal (gravity) force. As a result, large moons cannot survive inside the Roche Limit. On July 7,1992, Comet Shoemaker-Levy 9 broke apart into 21 pieces due to tidal forces when it passed within Jupiter s Roche Limit on the subsequent pass, each of the comet s pieces collided with Jupiter. 

It was a big surprise when on lo active volcanism was detected on its surface (see Eig. 4.1). On Earth, the heat source that produces volcanic activity comes from its interior where radioactive materials decay and release energy and also from heat left over from its formation, accretion heat. This however cannot explain the volcanism on lo. The satellite is too small and should have cooled out. The only mechanism to maintain active volcanism on lo is tidal heating (see also Moore, 2003 [236]). The semi major axis of the orbit of lo is 421800 km so it is close to Jupiter and exposed to strong tidal forces. One revolution around Jupiter takes only 1 d 18 h 27 min. The albedo of lo is 0.61 which is a relatively high value. Other parameters... 

On the surface of lo 400 active volcanoes and more than 150 mountains have been detected. There are volcanic plumes that extend up to 500 km. The tidal forces of Jupiter on lo are 6000 times stronger than those of the Moon on Earth. In addition to these forces, there are also tidal forces caused by the two other Galilean satellites Europa and Ganymede (these are comparable to the tidal force of the Moon). Furthermore, the strength of these forces varies because the orbit of lo is elliptical. The variation of the tidal forces of Jupiter due to lo s elliptical orbit is 1000 times the strength of the tidal forces of the Moon. 

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