Have you heard of ISON? If you haven’t, perhaps you haven’t been keeping your eyes upon the stars. ISON is the name given to the comet to have most recently entered our inner solar system. It hails from our solar system’s Oort cloud, a vast mass of bodies that have come together to form…well, basically a big cloud at the edge of our solar system. It’s so far away (4.6 trillion miles, give or take), that passing stars can actually change the orbits of the objects within the cloud. ISON was one of these objects.
ISON was discovered back in September of 2012 by the International Scientific Optical Network – hence the comets nickname, ‘ISON’ – a Russian observatory. While it’s discovery was fairly recent, it’s journey toward the sun has already lasted a million years or so according to scientists. But why get so worked up about a comet that’s actually smaller than most we come across?
Well first of all, it’s orbit is almost a perfect parabola. What’s that? Basically, it’s almost a perfect U shape – which means that it’s most likely the first time it has ever come into the inner solar system. Not only does it have a near perfect parabolic orbit, it’s a sun-grazer. That means it is headed to the sun and is going to get less than 1.2 million km away as it passes by. While that looks like a big number, it’s really very close and means that the comet is exposed temperatures up to 2,700 degrees celsius – hotter than Vulcan!
While I’ve been using present tense in reference to the comet, it’s possible that past tense may be more appropriate. Scientists aren’t sure if it has survived its close encounter with the sun. In fact, most thought it had disintegrated – until a smaller, dimmer object appeared on the other side of our bright star. Was it ISON? Did the comet survive? Even now, experts aren’t sure, though NASA has given up hope. Regardless, the comet captured the attention of astronomers around the globe. Unfortunately, while it had originally been speculated that ISON could be visible to the naked eye after it passed the sun, it seems that we will not have the opportunity. Don’t despair, however. Another comet, nicknamed Sliding Spring, is headed our way – and may possibly even toss some cookies over at our neighbor, Mars. Keep your eyes to the skies!