Over the next few weeks UK stargazers will have a chance to see a bright comet in the western sky at sunset.
The comet is called PanSTARRS C/2011 L4, or PanSTARRS to its friends, and was named after the PanSTARRS 1 (Panoramic Survey Telescope and Rapid Response System) telescope in Hawaii, which was the telescope used to discover the comet in 2011.
Since then Comet PanSTARRS has been nearing the Sun, heating up, and forming a long bright tail as the surface ices on the comet sublimate into gases.
Comet PanSTARRS has been visible in the southern hemisphere for a while now, but it’s only now that northern stargazers will get a chance to see it.
Over the next week you’ll probably need binoculars to see it, but it may brighten to become a naked eye comet later this month.
Here’s a star map showing where it will be in the sky over the next month:
This star map shows the view looking west just after sunset. The red crosses mark the path of the comet as it climbs in the sky, and the red numbers mark out the date in five day intervals, with 10 Mar being lowest on the map, then 15 Mar, 20 Mar, 25 Mar, 30 Mar, and finally 5 Apr. The horizontal line shows the horizon at 7pm in mid March, but the stars in this map will set earlier and earlier as we go into April. Put simply, you need to go and look west just as the sky begins to darken after sunset.
How best to see Comet PanSTARRS
There are a few tips to help you maximise your chances of seeing this comet:
1. Find an observing location with a clear western horizon (the west coast is ideal, but higher ground inland would be fine too).
2. Do your best to get away from very bright lights and out of city centres, where the horizon is normally built up anyway.
3. On 12 and 13 Mar the thin crescent Moon passes close to the comet, making it a little easier to find.
4. Don’t expect too much! The comet, even if it brightens as expected, will always appear low on the horizon, and in twilight, making it quite difficult to spot. Binoculars can really help you locate it.