Comet To Hurtle Past Mars In Rare Celestial Event

A comet is set to scrape past Mars on Sunday, in what scientists are calling a once-in-a-million-years encounter. NASA will document the rare event, which it is hoped will shed light on the origins of the solar system.



The comet, known as Siding Spring or C/2013 A1, is expected to hurtle past Mars at a close distance of about 140,000 kilometers (90,000 miles) at 1827 UTC on Sunday night. The comet is shooting through space at a speed of 196,984 kilometers per hour (120,000 mph) and is thought to have formed billions of years ago in the Oort Cloud, which is made up from material from the formation of the solar system.



"Comets such as C/2013 A1 are essentially dirty icy snowballs with rocks and dust embedded in frozen gasses," Dan Brown, an astronomy expert at Nottingham Trent University in the UK, told the news agency AFP.



"It is on its first run towards the center of our solar system and its material is virtually unchanged by the rays of the sun and can give us an insight to the material composition of our early solar system 4.6 billion years ago," he added.



Siding Spring has traveled more than 1 million years to reach the red planet, and another million years will pass before it returns.



Astronomers predict that, though the comet won't collide with Mars, its tail is likely to graze the planet, providing a rare opportunity to gather valuable data. NASA, the US space agency, has deployed more than a dozen probes, rovers and telescopes to document the near miss. Its Mars orbiters have also been moved to the far side of the planet so that they won't be hit by the comet's flying debris, but it is hoped they will still be able to capture some data from the event.



The US space agency announced that its two rovers, Curiosity and Opportunity, would turn their cameras skywards and send back pictures of the comet's passing.



"The orbiters will keep a close eye on the show ... They'll measure how the gas and dust interact with the Martian atmosphere," Rebecca Johnson, editor of StarDate magazine, told AFP.



"It gives scientists a chance to see a relic from the distant past - a snowball that preserves the same ingredients that gave birth to our own world," she said.



The comet gets its name from the Siding Spring Observatory in Australia, where it was discovered by Robert McNaught in January 2013.



nm/mkg (dpa, AFP)