Impact event such as Engelier and Gerin on Iapetus, Mamaldi on Rhea and Odysseus on Tethys and Herschel on Mimas form significant surface features. 2018 models developed to explain the unusual spin of Uranus support a long-held theory that this was caused by an oblique collision with massive object twice the size of Earth. On July 1994, Comet Shoemaker–Levy 9 was a comet that broke apart and collided with Jupiter, providing the first direct observation of an extraterrestrial collision of Solar System objects. The event served as a "wake-up call", and astronomers responded by starting programs such as Lincoln Near-Earth Asteroid Research
David H. Levy of Allusions to Celestial Events in Elizabethan and Jacobean Writing, 1572–1620." Starting in 2015, Levy has been donating his observing logs, which he has kept continuously since 1956, his personal journals since 1958, and his comet search records since 1965, to the Linda Hall Library of Science Library in Kansas City. The observing records are also on-line at the website of the Royal Astronomical Society of Canada. He lives in Vail, Arizona and is married to Wendee Levy. Levy and his wife hosted a weekly internet radio talk show on astronomy, which ended on February 3, 2011, with a planned