A comet called C/2013 A1 Siding Spring is gradually reaching Mars for a rare and close flyby around the Red Planet on Oct. 19.
The comet's flyby caused NASA to shelter its Mars orbiters and rovers from the encounter, which will most likely put on a "barnstorming show" on the Red Planet, according to a press release issued by the space agency.
The comet was first discovered by an Australian comet hunter named Robert H. McNaight on Jan. 3, 2013 in the Siding Spring Observatory in New South Wales, Australia.
The comet will pass by at a distance that is 10 times closer to the planet's surface than any comet has flown past Earth. At the time of the discovery, Comet Siding Spring was farther from the Sun than Jupiter is, and was about 7.2 times farther away from the sun than Earth, according to NASA.
The comet isn't the only one with Siding Spring in its name, but is different from other similarly-named comets with the official prefix "C/2013A1," which means that it was the first long-period comet discovered in 2013.
The comet was found in the constellation of Lepus, according to NASA. It has travelled over one million years to reach Mars, on its first journey toward the sun, after being kicked out of the Oort Cloud.
"We don't have enough information yet to define the coma's size, but we do know it is likely to engulf all of Mars," a NASA statement said.
The comet is unlikely to crash into Mars, though the planet will most likely pass through its coma of gas and dust. Rovers on Mars could witness a meteor shower similar to the Leonid shower that many people enjoy on Earth.
When C/2013 A1 Siding Spring's coma will surround Mars, dust and other particles will be traveling at around 125,200 miles an hour, or about 35 miles a second, according to NASA.
"The Martian atmosphere, thin as it is, is dense enough to prevent incoming dust from the comet from becoming a hazard to NASA's two Mars rovers active on the surface," the space agency said.
The comet isn't expected to make a comeback for another million years.
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