The annual Perseid meteor shower reaches its peak on Wednesday night, with shooting stars visible across the UK. This year, the peak comes just hours after a partial eclipse plunges the country into early twilight on Wednesday evening.
Every summer, Earth slams into a trail of debris from the Swift-Tuttle comet, which also orbits the Sun. Specks as small as a grain of dust or rice flare up under the pressure of the planet's atmosphere to create shooting stars, according to Royal Observatory Greenwich astronomer Dr Ed Bloomer.
How many meteors can be seen?
Around 150 meteors cross the sky per hour, but that amount is not visible because the horizon blocks a full view, Dr Bloomer said. However, an estimated 100 meteors could be seen per hour in certain locations that are particularly flat and dark.
The meteor shower has been running for a few weeks and will continue until around August 23, meaning there are "lots of chances to see this," but "you have to let your eyes adjust to the dark." Dr Bloomer recommended stargazers wait half an hour to let their eyes get used to it, adding: "Take a camping chair or something – if you had one, you would just sit down, and you would just relax, and you would just wait."
Tips for the best view
He advised: "You want to get away from city lights, you want to get away from street lamps. If you're looking out from your garden – it sounds obvious – but switch the kitchen light off, give yourself time to just put the phone away." People struggling to see the meteors can turn and watch through their peripheral vision as it is "a little bit better with low light conditions," he said.
As it is summer, viewers will also have to wait until relatively late at night for it to be dark enough to see the celestial show. The meteor shower will be in the north-east as the sun is going down, Dr Bloomer added. He said: "However, it's not available to everybody, because the further south you go… Perseid is lower and lower on the horizon."
Viewing from the UK
"The primary interest is for Northern Hemisphere observers – Perseid is pretty low for us here in the UK, but it is above the horizon… in fact, it's above the horizon all day, but the problem is, of course, during the day, nothing's going to be visible." Despite it being more visible in the north, "the dominant thing is going to be, can you get yourself in a dark location," he added. "Getting into the middle of a field in the south east of England, in London, is going to be better than being in the middle of Aberdeen."
Fireballs and rarer meteors
Shooting stars generally only last a second or two and sometimes appear in flurries, the astronomer said. Rarer meteors the size of a fist or basketball will produce longer tails and are known as fireballs, he added. These can last five to 10 seconds, but Dr Bloomer said he has only ever seen one. The level up is a bolide but "that's a sort of national emergency type thing," he added.
