This week on Looking Up Hal gives us the extended celestial forecast - partly cloudy, with a chance for comets...
I admit it; I’m a sucker for comets. I can’t help but wax a tad philosophic when I think of these remarkable and ancient objects. There are famous comets that come back regularly – think Halley’s Comet – and there are others, like the very bright Comet West back in 1976, that have much larger orbits, over 70,000 times the Earth-Sun distance, and so won’t return for about 500 million years, give or take.
Comets are left over stuff from the dawn of the Solar System, and they come from a vast cloud of comets, with perhaps 2 trillion of them, way out in a thing called the Oort Cloud. This sphere of comets surrounds the Solar System way out there, perhaps half way or more to the nearest star beyond our Sun. I’m talking really big.
So, a comet dropping by is pretty cool, and it happens more often than you might think. The media only gets excited when they are particularly bright, or when some website guesses the comet is going to smack into the Earth. Again, space is big, no worries.
There is a very pretty but very dim comet up there right now, and what makes this one special is the neighborhood. If you have a telescope (or come to one of our star parties), you can see comet Panstarrs C/2016 R2 very near the gorgeous star cluster known as the Pleiades. A quick Google search can get you a star map, and so take a look at this ancient ice ball as it visits and then heads back into space for 20,000 years or so.
If you’d like to take a closer look at the comet, or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.