Astronomy – A Christmas Comet

Whizzing along at 70 kilometres per second and about 35 million kilometres away from us is a comet. 

Comet Leonard (C/2021 A1 (Leonard)) is coming closer to earth and moving into a position where we will soon be able to observe it. Is it going to be seen by the naked eye? Would we need a telescope? The answers are not always that clear.

Last weekend, on December 18, the comet will have had a close encounter with Venus, coming to within just 4 million kilometres of our closest planetary neighbour. The comet will also have been visible from New Zealand on that date.

By Christmas night the comet should be relatively high in the sky. At its brightest, it could reach a magnitude that will look like a fuzzy blob to the naked eye, or clearer in binoculars. Through a good, relatively small telescope it will look magnificent. 

As a comet gets closer to the Sun, it heats up and can break apart. We do not know if that will even happen. It is possible that it will swing around the sun unharmed, to continue its journey back into the darkness of space. 

Should it survive, the comet is predicted to swing around the Sun on January 3, 2022. However, this is unlikely as the comet is already quite unstable and will almost certainly break apart before reaching this point.

Comet Leonard was discovered on January 3 this year by US astronomer Greg Leonard. 

At about just 1 kilometre across, the “dirty snowball” is basically a lump of ice and rubble that is left over from the formation of the Solar System 4.5 billion years ago. The comet moves in a highly elliptical orbit that takes it out about 3,700 times further from the Sun than the earth is.

Remember to use your astronomy apps on your phone to help you find it in the night sky. 

And once you find it, spend a little longer outside on these warm summer evenings and see what else is up there! 

From the Hibiscus Coast Astronomical Society, we wish you all a very merry Christmas and a blessed and prosperous New Year.