NASA watched as a comet headed towards Mars spewed out twin jets.
The comet, dubbed C/2013 A1 or "Siding Spring" will pass as close as 84,000 miles of Mars on Oct. 19, a NASA news release reported. This is only half of the distance between Earth and the moon.
Siding Spring is believed to have an icy nucleus, but NASA's Hubble telescope was not able to capture it because of its "diminutive size."
The comet is also characterized by a surrounding dust cloud that glows. The dust cloud (also called a COMA) is about 12,000 miles across.
Processing techniques on the Hubble images removed the hazy COMA glow and revealed what are believed to be two jets of dust shooting from the comet's nucleus in opposite directions. These observations could allow researchers to measure the "direction of the nucleus's pole, and axis of rotation," the news release reported.
"This is critical information that we need to determine whether, and to what degree, dust grains in the coma of the comet will impact Mars and spacecraft in the vicinity of Mars," Jian-Yang Li of the Planetary Science Institute in Tucson, Arizona, said in the news release.
The images were taken on March 11, but Siding Spring was also observed on Jan. 21 as Earth was crossing its orbital plane (" the path the comet takes as it orbits the sun"). These logistical circumstances allowed researchers to measure the speed at which the dust was flying off the comet's nucleus.
Siding Spring was first discovered in January 2013; the object is "falling towards the Sun" in a one-million-year-long orbit that is within the reaches of Jupiter's.
The comet is expected to make its closest-known pass with the Sun on Oct. 25, in which it will be about 130 million miles away; this is much farther out than Earth's proximity to the Sun. During this time Siding Spring should be close enough for Earthly star-gazers to spot it with the naked eye.
