At just one third the distance of our Moon, Comet Siding Spring (C/2012 A1) is set to pass Mars ten times closer than any recorded comet has ever passed Earth. As NASA currently have two spacecraft orbiting the red planet (and one on the way), cautionary measures are being drafted to manoeuvre the spacecraft (if necessary) out of harms way.
It may not be known for a few months how much of a threat Comet Siding Spring will be, and although its course is now well mapped out, it’s the sheer unpredictability of how active the comet will become that has scientists preparing for the worst case scenario. Between now and May, Siding Spring will draw close enough to the Sun for ice on its surface to start vaporizing and releasing dust particles, these particles drift slowly away from the comet and by October could be abundant and dense enough to envelop Mars as Siding Spring passes by.
After two and a half years without any contact from Earth, the Rosetta Spacecraft’s internal alarm clock sounded on January 20th at 10am UTC to bring it out of its deep space hibernation period. After initially warming up its star trackers and going through a series of self checks, Rosetta then pointed its 2.2m high-gain antenna towards Earth and sent a signal home.
The signal, which came in around 18 minutes later than anticipated, was picked up by NASA’s 70m dish antenna in Goldstone, California and then relayed to mission control at ESA’s European Space Operations Centre in Darmstadt, Germany. There were cheers from the flight controllers as Rosetta’s long anticipated signal indicated that Rosetta was in good shape and ready to proceed with the 980m dollar comet-chasing mission.
The Rosetta Mission will resume autonomously on January 20th at 10am UTC, when the spacecraft’s internal alarm clock is set to wake it up from it’s two and a half year hibernation. However, it won’t be until several hours later until the European Space Agency know if the ‘wake up’ was successful.
In July 2011, the Rosetta Spacecraft pointed its solar panels in the direction of the Sun and went to ‘sleep’. Despite having two enormous 14 metre solar arrays that allow it to operate many millions of miles from it’s power source (the Sun), this distant leg of the journey required Rosetta to conserve power.