The Hartley 2 Comet’s Whistle Stop Tour Itinerary
The periodically visible Hartley 2 Comet will make its best appearance since its discovery over Cape Town skies from late September through to early November.
Please, enjoy this simple explanation from the Astronomical Society of Southern Africa.
This comet is at perihelion on October 28, just a week after it makes a very close approach to the earth. Consequently observing conditions are very favourable, though the northerly declination may be problematic. It should be visible in binoculars in September and may reach naked eye visibility in October as it moves through Perseus and Auriga. Best observing chances for southern Africa are probably the first week of November, when the comet should still be on the borderline of naked eye visibility, rising at 10.30 pm SAST behind Orion. The comet remains well placed for southern Africa to monitor its fading well into 2011 as it crosses Monoceros, Puppis and Canis Major.
The comet should show two tails emanating from the coma encircling the nucleus, which is of course a giant ball of ice and dust 1,6 kilometres in diameter. As sunlight hits the nucleus, the ice boils off and carries dust with it. Sunlight then ionizes the ejected gas molecules, causing them to glow with a bluish color. The solar wind carries this ionized gas away from the comet, creating a straight, bluish gas tail. The ejected dust gets pushed away from the Sun more gently, so it forms a curving tail. The dust particles simply reflect sunlight, so the dust tail has a white to pale-yellow color.
All pretty standard stuff, really.
I was thinking about Canis Major just the other night, in between throwing marbles at pigeons and judging Noleen on 3Talk. Isn’t awesome how the universe works? Our stars must have aligned.
Well, there you have it. You heard it first on 2oceansvibe, folks.
[Source : ASSA]
