Comet Shoemaker-Levy 9 was discovered photographically by the husband and wife scientific team of Carolyn S. and Eugene M. Shoemaker and David H. Levy on March 24, 1993, using the 0.46-m (18-in.) ... Its discovery was a serendipitous product of their continuing search for near-Earth objects , and the 9 indicates that it was the ninth short-period comet (period less than 200 years) discovered by this team. ... In other words, the comet, or at least parts of it, could very well hit Jupiter. ...

... Comet Tutorial . ... On July 1, 1993 an image was taken with the Hubble Space Telescope (HST) that clearly shows at least 15 individual fragments in one image frame of the train. ... This made an accurate orbit (or orbits) difficult to determine; however, after numerous observations of the comet, astronmers determined that the comet had passed within 96,000 kilometers (60,000 miles) of the center of Jupiter or 25,000 kilometers (16,000 miles) from the cloud tops during the July 8, 1992, approach. ...

... 9a. Earth orbits Sun? . ... 10a. Scale of Solar Sys. ... If the mean distance of Earth from the Sun is 1 AU ("Astronomical Unit"), then that of Venus is 0.723 AU, of Mercury 0.387 AU and that of Mars is 1.524 AU. ... By noting (1) where on the Sun's disk is the crossing seen, (2) timing its duration at two far-apart points on Earth, and (3) comparing the times, one can calculate the distance to Venus and from it the scale of the solar system. ... One occurred in 1639--too early. ...

Cosmic Research, Vol. 42, No. 5, 2004, pp. 435­488. Translated from Kosmicheskie Issledovaniya, Vol. 42, No. 5, 2004, pp. 453­508. Original Russian Text Copyright © 2004 by Veselovsky, Panasyuk, Avdyushin, Bazilevskaya, Belov, Bogachev, Bogod, Bogomolov, Bothmer, Boyarchuk, Vashenyuk, Vlasov, Gnezdilov, Gorgutsa, Grechnev, Denisov, Dmitriev, Dryer, Yermolaev, Eroshenko, Zherebtsov, Zhitnik, Zhukov, Zastenker, Zelenyi, Zeldovich, Ivanov-Kholodnyi, Ignat'ev, Ishkov, Kolomiytsev, Krasheninnikov, Kudela,