Mars-Bound Comet ‘Siding Spring’ Will Have a Close Brush with Mars

NASA recently released an image of a comet that will traverse within 84,000 miles of Mars later this year, less than half the distance between Earth and the moon.

The space agency's Hubble Space Telescope captured comet C/2013 A1 that is going to have a close brush with Mars on October 19. The comet also called as 'Siding Spring' was captured on March 11 at a distance of 353 million miles from Earth. The image shows the comet engulfed in a bright cloud of cosmic dust that measures nearly 12,000 miles across. Due to the extreme small size, Hubble could not spot the nucleus that was surrounded by dust or COMA.

After processing the image of the comet, the researchers saw that the comet has two jets of dust emitting out of the nucleus in opposite directions.  Analyzing this image, the astronomers hope to measure the direction of the nucleus's pole including the axis of rotation.

Prior to this, the Hubble had monitored the Siding Spring earlier this year as Earth was crossing its orbital plane. The comet takes this path as it orbits the sun, the comet is descending toward the sun along a 1 million year orbit. Based on the position of the two bodies, the astronomers calculated the speed of the cosmic dust emitting off the comet's nucleus.

"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," said Jian-Yang Li of the Planetary Science Institute in Tucson, Arizona.

The Siding Spring was discovered in January 2013 by Robert H. McNaught. Currently, the comet is descending toward the sun along a 1 million year orbit and lies within the radius of Jupiter's orbit.