Question

question 1

Comet Shoemaker-Levy 9 was captured into orbit around Jupiter in the 1960s or 1970s. The comet was tidally disrupted on a close approach with Jupiter in July 1992 and collided with the planet in July 1994. Estimate how close the comet must have approached Jupiter in 1992 in order that it was tidally disrupted, assuming that the comet was loosely bound only by its own gravitational forces.

question 2

Consider a star of mass M = 0.5M(dot) and luminosity L = 0.1L(dot). Assume that the star begins it life as 74% H, 24% He, and 2% other elements (by mass) and that over its lifetime the star is able to convert 10% of its H to He via the p-p chain nuclear fusion reaction. What is the lifetime of the star, in units yr? Take M(dot) = 2.0× 1030 kg and L(dot) = 3.8× 1026 W, and recall that 0.007 of the mass of the orignal H atoms is released as energy via the p-p chain.

Answer 1

a. Comet passed extremly close to Jupiter over 40 000km abpve its cloud top. This is a smaller distance than jupiters radius . Its radius is 70 000km . So its passed inside the orbit of jupiters innermost moon and the planets Roche limit inside which the tidal forces will be strong enough to disrupt its own gravitational forces.

b