Satgen636 Comet Origin/Content by GM4IHJ (BID SGEN636) 2001-06-02 NASA has recently proposed a mission whereby a projectile will be fired at a Comet (Tempel ?), with sufficient force to cause the comet to break up. At which point spectral analysis of the residue , might provide details of its composition. Then with its constituents revealed. It should be possible to determine , where and when that particular comet was born. Two recent comets, seem however, to have jumped the gun, by disintegrating without human assistance, and the manner of their departure may cast some doubts regarding the possible success of the proposed NASA mission. Both disintegrating comets were discovered by Lincoln Laboratory astronomers using the 1 metre telescope at Socorro in New Mexico. So both are called Comet Linear, consequent on their discovery by the Lincoln Lab near earth survey. But they are distinguish by adding the year number of their discovery. 2000 broke up in July 2000 as it passed near the Sun, 74 million miles from earth. Providing a spectacular display which indicates a low ratio of Carbon Monoxide to Water in its composition. A result which appears to indicate that it was born as the solar system coalesced, somewhere near Jupiter , and certainly no further out than Uranus or Neptune. At some time there after it was ejected outwards away beyond the big gas giant planets . Remaining in the cold region beyond Pluto in the Kuiper Belt or even further out in the Oort Belt, before being pushed back into the inner solar system on what proved to be its last journey. As it came apart near the Sun it produced more questions than answers. In that the observed collection of small lumps left after break up represented less than one hundredth of the assumed, mass before break up. However this pre /post mass difference may be an illusion , noting that the diffuse gas cloud surrounding the post break up debris, is probably hiding a great deal of material . A situation which if it occurs after break up in the proposed NASA comet buster experiment. Could upset the collection of useful data. Interestingly however. This is not the end of the story. The Linear experiment found another comet - LINEAR 2001 A2 , in January 2001. This comet broke up as it too came near the Sun in May 2001 , and once again the break up has produced a diffuse debris cloud which makes direct observation of the debris very difficult. Perhaps there will be some profit in the end. Presumably the stream of debris from both comets will generally follow the original orbit back around the Sun and could perhaps cross earth orbit sometime in the future , providing radio meteor observers with a super shower.