Every body is held together by two forces, its self-gravitation and its internal strength due to molecular bonding. ... A few of these cases have been obviously attributable to the tidal forces of Jupiter (Comet Brooks 2 and Comet Shoemaker-Levy 9) or the Sun (the Kreutz comet family), while other splittings have to be attributed to less obvious causes. ... They always approach the Sun to within 3 million kilometers (1.9 million miles) or less, and some have actually hit the Sun. ...