Madsen Pirie

It might happen, but there’s a big question mark about whether it will survive its trip around the sun.  Its orbit gives it a very close pass, some 1.2m km at its closest, which it reached yesterday evening.  When you reflect that the sun’s diameter is 1.39m km, you appreciate that it passed the sun less than a diameter away.  Given the intense heat and radiation, some observers have speculated that Comet Ison might not survive.  In its favour is its size, with estimates that it might be several kilometres in diameter.  It is also moving fast, at over 1m kph.  Much of that mass will be ice of various kinds that will vaporize.  This could give us a show as matter is ejected to form a characteristic comet’s tail.  Ison came from the Oort Cloud at the edge of the solar system, a region harbouring original matter that did not take part in the formation of planets.  Astronomers disagree about whether we are in for a spectacular in early December.  Some say it could be “the comet of the century” – not that there’s been much competition yet in the 13 years we’ve had so far of that century.  It could give us a show in the evening sky just after sunset, or in the dawn sky just before sunrise.  Some suggest it might be only just visible to the naked eye or with binoculars.  And others think it will break up as Comet Lovejoy did in 2011.  And Shakespeare scholars will note that it portends good news for beggars and bad news for princes.  (“When beggars die there are no comets seen.  The heavens themselves blaze forth the death of princes”).

Filed under: Updates |