A pristine comet is heading towards Mars, approaching closer than one third of the distance from the Earth to the Moon. Astronomers are preparing for an exciting astronomical event that occurs just once in a million years, RT reported.
At a speed of 202,000 kilometers per hour (kph), the Siding Spring comet, a mountain-sized ice ball accompanied by a gigantic trail of dust, is scheduled to miss the red planet by just 140,000 km at on Sunday. Named after the Australian observatory where it was discovered in 2013, the comet has a nucleus, or icy core, with a diameter estimated at 0.8 to 8 km.
The closest observers of this historic event are the three NASA robotic explorers, India's Mangalyaan spacecraft and Europe's Mars Express. Using a "duck and cover" strategy after the observations, the orbiters have been repurposed to hide for about 20 minutes behind the planet’s body. This will protect them against the comet’s potentially harmful trail, which is as long as from here to the moon and is expected to engulf the entire planet. However, the Opportunity and Curiosity rovers are set to get the best view, if no dust storm on Mars obscures the planet’s sky. Astronomers are anticipating the encounter and will be monitoring via Earth-based and space telescopes, such as the Hubble Space Telescope. "We're getting ready for a spectacular set of observations," said Jim Green, head of NASA's planetary science division.
South Africa and Australia are topping the list of best places for viewing via binoculars or telescope. In the Northern Hemisphere, it will be quite difficult to catch a glimpse of the comet. But the Siding Spring observation campaign will be prolonged, should the comet survive its encounter with Mars. Scientists are planning to follow its way back home, the Oort Cloud, located on the outskirts of the solar system, which marks the border of the Sun’s gravitational force.
