On 28 September at 02:07 BST a supermoon eclipse will be visible from the UK. Inevitably, with every astrological event, doctored photos are shared on social media in order to garner retweets and favourites. WIRED asked the Royal Astronomical Society how to spot a fake picture of the moon, and how best to take your own picture of the upcoming event. And if you want to avoid looking the fool, don't repost any of the obvious fakes collected on this page.
The key to spotting a fake picture of the moon is not, according to Robert Massey at the RAS, trying to work out if the size is too big. "That can be pretty hard to tell because it's complicated without knowing the details of the shot," he tells WIRED. In order to spot a fake, the trick is to try and work out which part of the sky the photo was meant to be in, and compare it to the stars in the sky. "Someone with the right software could do it, if you tell them the moon they were seeing. If there were bright stars near by, you could compare the contents of the picture with what should have been in the picture."
There are also some classic scientific mistakes to look out for. "You wouldn’t see a full moon in the daytime sky for example, that’s impossible. Certainly if you the sun and the full moon in the same picture, that would be a fake picture."
If you want to avoid accidentally sharing a fake photo, why not take you own?
"With a decent digital camera and a decent lens it's not that hard, actually, because digital cameras are so sensitive. You'd have to try a range of exposures but a full moon, because it's normally still quite bright, but you can probably get away with a shot that's a few seconds."
For that you need some basic equipment -- a camera, a telephoto lens and a tripod -- but really the main thing is to make sure the weather is kind and the sky is clear enough to get a a good shot. "Once you get up to that kind of exposure length you need a good tripod, and you need a telephoto lens," he says. "Although the moon looks big to the eye, it's actually quite small in the sky"
Just a little tip to finish off that winning photo -- "If you want to do something dramatic, get a telephoto and wait for it to be rising or setting, or near interesting objects because the composition is better."
This article was originally published by WIRED UK
