By Philippa Rickard
I don’t need to tell you about the sheer volume of rain falling from the sky recently, but have you seen the meteors? Every year, over July and August, we pass through debris from the tail of Comet Swift-Tuttle; we know this debris as the Perseid meteoroids. Most are as small as a grain of sand but some are as big as a marble, and all are travelling up to 133,000 miles per hour (that’s 37 miles per second!). They light up our skies when they are about 60 miles from the ground, as they burn up in the Earth’s atmosphere as meteors.
Swift-Tuttle is composed of ice and rock with an orbital period of 133 Earth years. Its diameter of 26 km and mass of 7,500,000,000,000,000 kg make it the largest comet to periodically orbit Earth. The last time we could see Swift-Tuttle pass by Earth with our naked eye was 1992 and the next time will be in 2126.
The 2017 Perseid meteor shower will reach its peak this coming weekend. The normal rate for this shower is 80-100 meteors per hour, but this year NASA are predicting enhanced rates of about 150 meteors per hour. That’s a few meteors per minute. Unfortunately, the fainter Perseids will be outshined by the bright light of the waning gibbous moon. But don’t despair! If you can see stars in the sky then you will see meteors.
It is certainly worth heading out to catch a glimpse of this annual phenomenon, and you will have a better chance of seeing more meteors away from artificial light. We are incredibly lucky in Newcastle, we have Europe’s largest area of protected night sky on our doorstep, Northumberland International Dark Sky Park. The shower will peak during the pre-dawn hours of 12th August, but there will be a decent show over both Friday and Saturday nights. Perseids appear to radiate out of the Perseus constellation, but you don’t need any special equipment or knowledge of the stars. Just look north-east and be patient (and maybe take along a cosy blanket, a reclining chair and a flask of tea).