MOSCOW, October 18 (RIA Novosti) - An icy, rocky visitor from outer space is rapidly approaching our neighboring planet Mars, and while the Red Planet isn’t in any danger, the stream of debris and gas that is trailing the comet may pose a threat to the fleet of Terran spacecraft in orbit.
Comet Siding Spring is expected to fly by Mars at a distance of 87,000 miles (139,500 km) Sunday, which is about one third the distance between the Earth and the Moon, say NASA experts as quoted by ABC News. The comet will be at its closest to Mars at 2:27 PM ET tomorrow, tearing through space at a speed of 34 miles (55 km) per second (for comparison’s sake, a bullet fired from an AK-47 travels at 0.45 miles (715 m) per second). Meanwhile, NASA scientists have expressed concern that the comet’s tail of dust, rock and ice debris and gas may damage or even demolish the satellites that have been placed in orbit around the Red Planet in order to study it.
"Mars will be right at the edge of the debris cloud, so it might encounter some of the particles – or it might not", says Rich Zurek of the Mars Exploration Program at NASA's Jet Propulsion Laboratory as quoted by CNN. This bears certain risks as even a tiny fragment of hard matter, traveling at an enormously high cosmic speed, can harm or destroy a cosmic probe.
"It only takes a half-a-millimeter-sized particle traveling at 56 kilometers per second to injure one of these spacecraft", Don Yeomans of the Near Earth Object Program Office said in a NASA interview.
NASA, for its part, is going to move its most important space probes, including the Mars Odyssey orbiter, Mars Reconnaissance Orbiter (MRO), and the new Mars Atmosphere and Volatile Evolution (MAVEN), to the other side of the Red Planet until the comet is gone and the danger subsides.
The official name for the comet is C/2013 A1, and it is widely known as Siding Spring because it was first discovered by the Australian observatory of the same name in 2013. The icy visitor is about 0.5 to 5 miles wide and it includes some talcum powder, says Carey Lisse of Johns Hopkins University Applied Physics Laboratory as quoted by the LA Times. The gas and debris cloud around the comet measures 12,000 miles (19,312 km) in diameter.
Comet Siding Spring comes from the Oort cloud, a distant, spherical cloud of icy planitesimals that orbits the Sun at a distance of up to 50,000 AU, about ¼ of the distance between the Sun and its nearest neighboring star. The comet won’t be visible to the naked eye from Earth, and even with a telescope it can only be seen from the Southern Hemisphere. However, the Slooh virtual observatory will be streaming a view of the comet and Mars live starting at 11:15 AM PDT Sunday.
