Extinct comet

of 9P/Tempel as imaged by the NASA Deep Impact space probe. This is not yet extinct, but gives some idea of a cometary nucleus. An extinct comet is a comet that has expelled most of its volatile ice and has little left to form a tail and coma. In a dormant comet, rather than being depleted, any remaining volatile components have been sealed beneath an inactive surface layer. Due to the near lack of a coma and tail, an extinct or dormant comet may resemble an asteroid rather than a comet and blur the distinction between these two classes of small Solar System bodies. When volatile materials such as nitrogen, water, carbon dioxide, ammonia, hydrogen and methane in the comet nucleus have evaporated away, all that remains is an inert rock or rubble pile. A comet may go through a transition phase as it comes close to extinction.

of 9P/Tempel as imaged by the NASA Deep Impact space probe. This is not yet extinct, but gives some idea of a cometary nucleus.]] An extinct comet is a comet that has expelled most of its volatile ice and has little left to form a tail and coma. In a dormant comet, rather than being depleted, any remaining volatile components have been sealed beneath an inactive surface layer. Due to the near lack of a coma and tail, an extinct or dormant comet may resemble an asteroid rather than a comet and blur the distinction between these two classes of small Solar System bodies. When volatile materials such as nitrogen, water, carbon dioxide, ammonia, hydrogen and methane in the comet nucleus have evaporated away, all that remains is an inert rock or rubble pile. A comet may go through a transition phase as it comes close to extinction. (e=0.66) comet-like orbit of Hypnos.]] Suspected or hypothesized extinct comets include: 14827 Hypnos 2101 Adonis 2015 TB145 3200 Phaethon 3552 Don Quixote P/2007 R5 (SOHO 1) 1996 PW possibly an extinct long-period comet

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