Here is a stereo – possibly the first and only stereo picture of Comet Garradd in the world right now ! I made it from a beautiful photo by Prof Greg Parker … and … well, just for once, I am not going to tell you how!!
But it’s fun. It’s an odd shape for a comet – right But, viewed in stereo, it is much clearer what we are really looking at. This comet, like most comets which brighten up our skies, has two tails. One is made of mostly rocky dust, and this dust tail, usually warm in colour, is strewn out as a trail, along the path in space the comet has just travelled – like ski tracks in the snow, showing where the skier has been. But the other tail, usually blue in colour, is made of a tenuous ‘gas’ of ions … and this material is literally blown off the comet’s nucleus by the particles in the Solar Wind. So this gas tail always points AWAY from the Sun. The reason this particular comet looks so odd is that we are viewing it from an odd angle. It is situated far from the ecliptic … way outside the plane of the Solar System … so we are seeing the tails from an unusual angle, and foreshortened. 3-D sorts it out. Comet Garrad is in the Northern part of the sky right now, and apparently visible in binoculars – though I have not had an opportunity to find it in the sky myself yet.
Enjoy – from the comfort of your armchair!
See also Prof Parker’s website at HERE.
And this is the photo in 2-D