When and how to watch the 2018 Perseid meteor shower
For sky-watchers in the north, this weekend promises to be spectacular. Ben Lewis reports.
The Perseid meteor showers are an annual summer highlight for the northern hemisphere, when seemingly hundreds of meteorites flash across the sky, moving fast and leaving long “wakes” of light and colour behind them. This weekend promises to be the best time to check it out, and here’s everything you need to know.
The peak of the Perseid shower this year will be on the night of Sunday 12 August until dawn on Monday morning. The best times to view will be for 12 hours starting at 9pm in the UK, 10pm in Germany, 6pm on the East Coast of the US, and 3pm on the West Coast. India’s best viewing begins after 1.30am on the morning of Monday 13 August.
For those in the southern hemisphere however, it won’t be as spectacular. Perseids appear to come from the direction of the northern hemisphere constellation Perseus, making them primarily a northern phenomenon. With Perseus barely peaking above the horizon in the southern hemisphere, the best places to catch a view will be from as far north as possible – in Australia, try Darwin or Cairns – and the best time just before dawn when Perseus will be at its highest.
During the Perseids' peak this month, sky-watchers in the north should see about 60 to 70 meteors per hour, with some estimates as high as 100. However, in some years the count has been far more, with 2016 peaking between 150 and 200 meteors an hour.
Making up for it this year, however, is a moonless night, providing ideal conditions to see the streaks of light.
“The moonless sky this year means the viewing will be excellent, and the shower’s predicted peak is timed especially well for North America,” notes Diana Hannikainen from the online magazine Sky & Telescope. “Under a very dark sky, you might see up to one Perseid per minute late on Sunday night or after midnight on Monday morning.”
The meteors occur as Earth passes through the tail of Comet 109P/Swift-Tuttle.
This is a true behemoth, with a nucleus around 26 kilometres in diameter, making it the largest of the known periodic comets. Even though it only passes by Earth approximately every 130 years, our planet passes through its tail of dust and debris every year.
When you watch the meteor shower, what you’re seeing is sand-grain-sized items striking the atmosphere while travelling at 60 kilometres per second, creating a quick, white-hot streak of superheated air as they burn across the sky. The peak viewing time on 12 August comes as Earth passes through the densest area of dust.
The best thing about the Perseid meteor showers is that you don’t need any special equipment to view them. Just find a dark spot with a wide-open view overhead, and then sit back and enjoy the show.