JUST last month, stargazers were treated to a planetary feast, with five planets visible to the naked eye, plus Uranus for those with binoculars, gracing our early morning skies. Now, not one to be left out, Pluto is making an appearance. But it won’t be easy to see – you will require a telescope, dark skies and an eye for detail.
Pluto isn’t an official planet – it was downgraded to the status of dwarf planet in 2006. It is now one of , another of which is Ceres, the only dwarf planet found in the asteroid belt, which appeared in our skies last November. But Pluto, with its icy heart, has captured the hearts of many. Particularly those, like me, who were taught about the planets before 2006 and still remember their order using a mnemonic that ends in a word beginning with “P” (My Very Early Morning Jam Sandwich Usually Never Pleases, was mine).
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Planet or not, Pluto is small, only 1188 kilometres in radius, and extremely far away. Its distance from Earth varies, but currently it is around 5 billion kilometres from us, roughly 34 times our distance from the sun. This means it is impossible to see with the naked eye, or even with binoculars. Finding Pluto will require dark skies and a telescope that can see faint objects with magnitudes as small as 14.9.
Even with this set-up, Pluto will be tricky to identify because it will look just like a star through the telescope. Unlike the other planets, which appear as circles, Pluto is so far away it looks like a single point of light – as stars do. The only way to be sure that what you have seen is Pluto is to look at the same spot the next evening, and if the light you think is Pluto has moved, you were right.
The good news is, Pluto is reaching opposition – meaning it will be on the opposite side of Earth to the sun – on 20 July. This is the best time to try to spot it, and it means it will be easiest to view at midnight local time, wherever you are in the world.
Some places will get a better view than others. In the UK, Pluto will only rise a few degrees above the horizon, making it harder to find. In the southern hemisphere, it will rise much higher, and skies will be darker because it is winter, making astronomers in the south better placed to find the dwarf planet this time.
Regardless of where you are in the world, Pluto will appear between the constellations of Sagittarius and Capricornus. Use a star-finding app such as Stellarium to check exactly where Pluto will appear, as viewed from your area. You could even print a series of star charts, zooming in from easily identifiable stars until you can precisely locate the dwarf planet in the sky. It will be much more difficult to see Pluto than it is to see the true planets, but it is worth a try – if for no other reason than to not leave Pluto out, again.
What you need
A telescope
Dark skies
A star-finding app, like Stellarium
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