In the coming months we will be hearing a lot about Comet Siding Spring. IT’s going to come as close as 86K miles from the planet Mars. It’s gas and dust(coma) will interact with Mar’s atmosphere….jopipe
“Comet Siding Spring is making its first passage through the inner solar system and is experiencing its first strong heating from the sun,” said lead researcher Dennis Bodewits, an astronomer at the University of Maryland College Park (UMCP). “These observations are part of a two-year-long Swift campaign to watch how the comet’s activity develops during its travels.”
The comet makes its closest approach to Mars on Oct. 19, passing just 86,000 miles (138,000 km) from the Red Planet — so close that gas and dust in the outermost reaches of the comet’s atmosphere, or coma, will interact with the atmosphere of Mars.
For comparison, the closest recorded Earth approach by a comet was by the now-defunct comet Lexell, which on July 1, 1770, swept to within 1.4 million miles (2.3 million km) or about six times farther than the moon. During its Mars flyby, comet Siding Spring will pass more than 16 times closer than this.
Scientists have established that the comet poses no danger to spacecraft now in orbit around Mars. These missions will be pressed into service as a provisional comet observation fleet to take advantage of this unprecedented opportunity.
The Swift observations are part of a larger study to investigate the activity and evolution of new comets, which show distinct brightening characteristics as they approach the sun not seen in other comets. Bodewits and his colleagues single out comets that can be observed by Swift at distances where water has not yet become the primary gas and repeatedly observe them as they course through the inner solar system. This systematic study will help astronomers better understand how comet activity changes with repeated solar heating.