Overdue by an agonising fifteen minutes, signals confirmed that the European Rosetta spacecraft had woken up from its 3 year enforced hibernation and was beginning to warm and orient itself to make contact with the tracking stations on Earth. Launched in 2004, Rosetta has been coasting in an elongated narrow elliptical orbit, gradually picking up speed as it whipped by Earth and Mars until there was enough momentum for Sir Isaaac Newton to steer it on its way to its ultimate goal, the approaching comet 67P/Churyumov-Gerasimenko. With final course corrections in May, Rosetta will head for a delicate and nerve racking orbital rendevous with the comet in August . The real showpiece will be to land the attached probe Philae onto the comet’s surface where it will latch itself down. Both Rosetta and Philae will work together sending unprecedented amounts of data and pictures from this ancient relic of the early days of the universe. As it approaches the sun the comet should begin to warm and vent off the trapped gases which will all be observed at close quarters. The two craft will stay with the comet as it moves away from the sun and back into deep space. For more information go to the ESA web site and for a description of the mission go to here
A comet headed towards the Sun has the potential to be bright enough to be visible in the daytime skies of the northern hemisphere in 2013. The possibility of the stellar display was recently announced by two Russian astronomers. Officially known as C/2012 S1 (ISON), the comet was discovered by Artyom Novichonok and Vitaly Nevsky. The duo spotted it in images taken on September 21st 2012 with a reflecting telescope at the International Scientific Optical Network (ISON) in Kislovodsk in southern Russia. The comet is barely distinguishable from stars in the constellation of Cancer right now, but is likely to brighten a lot as it approaches the Sun. According to a Minor Planet Center report, on November 28, 2013, the comet will be at its perihelion, passing just 1.2 million kilometers from the surface of the Sun. If it survives the trip, the comet would then travel towards Earth. A month later, it will pass by our planet at a distance of about 63 million kilometers and be visible to the naked eye throughout January. According to some estimates, the comet could have a long tail and be brighter than the Moon. This scenario is far from certain, however. Comets’ behavior is difficult to predict, and C/2012 S1 is just as likely to fizzle out as become a global spectacle. Right now, the comet is near Jupiter, and is expected to rapidly brighten in August next year. Whether it will disintegrate or blaze across the sky remains to be seen. One point of intense speculation among media and astronomers is the similarity between this new comet and the Great Comet of 1680, an object that left a brilliant streak across the sky during that year. The two comets may be fragments of a single object that broke apart in the distant past. The new comet, named C/2012 S1 (ISON) was found by the International Scientific Optical Network (ISON) in Russia on 21 September when astronomers Vitali Nevski and Artyom Novichonok captured it on CCD images taken through a 0.4-metre reflector. Its near-parabolic orbit suggests that it has arrived fresh from the Oort Cloud, a vast zone of icy objects orbiting the Sun, pristine remnants of the formation of the Solar System. C/2012 S1 currently resides in the northwestern corner of Cancer. At magnitude +18 it is too dim to be seen visually but it will be within the reach of experienced amateur astronomers with CCD equipment in the coming months as it brightens. It is expected to reach binocular visibility by late summer 2013 and a naked eye object in early November of that year. Northern hemisphere observers are highly favoured. Following its peak brightness in late November it will remain visible without optical aid until mid-January 2014.