The Comet Siding Spring, an estimated eight to 50 kilometers in diameter, is apparently on course to have an exceedingly close call with the planet Mars in October 2014 and may even collide with the Red Planet.
The new comet C/2013 A1 (Siding Spring) was discovered Jan. 3 by the Scottish-Australian astronomer Robert H. McNaught using the 0.5-meter Uppsala Schmidt Telescope at Siding Spring Observatory, New South Wales, Australia.
When it was discovered, Comet Siding Spring was 1.07 billion kilometers (669 million miles) from the sun. It is expected to pass closest to the sun (called perihelion) on Oct. 25, 2014 at a distance of 209 million km (130 million miles).
But, less than a week earlier, on Oct. 19, 2014, the comet is projected to pass very close to Mars, within 101,000 km (63,000 miles).
However, because the comet is currently very far out in space and has been under observation for less than three months, its orbit will likely need to be refined in the coming months. So the comet’s approach to Mars might ultimately end up being farther or closer than what current predictions suggest. Last Wednesday observations made by Leonid Elenin, a reputable Russian astronomer who works at the Keldysh Institute of Applied Mathematics, suggested that the comet could pass even closer — just 41,300 km (25,700 miles) from the center of Mars.
According to Elenin: “On the 19th October 2014, the comet might reach apparent magnitude of -8 to -8.5, as seen from Mars!” (This would make the comet 15 to 25 times brighter than Venus). “Perhaps it will be possible to acquire high-resolution images from the Mars Reconnaissance Orbiter (MRO),” he added.
Then there is also the small possibility that the comet could collide with Mars.
Moving at 35 miles (56 km) per second, such a collision could create an impact crater on Mars up to ten times the diameter of the comet’s nucleus and up to 2 km (1.25 miles) deep, with an energy equivalent up to of 2 x 10^10 megatons!
You may recall Comet Shoemaker-Levy’s plunge into Jupiter in July 1994 which left dark telltale scars on Jupiter’s cloud tops for many months thereafter.
This will be the second close shave of Mars by a passing comet within a time span of just over a year… What are the odds?