DNA Explainer: What is August's Perseid meteor shower? Know what causes the spectacular annual celestial wonder

If you’re away from light pollution, you may be able to spot as many as 40 shooting stars a minute, says NASA.

The middle of August brings the most spectacular annual event of shooting stars in the sky – Here’s what are they, what causes them and what you can expect from the celestial show.

The Perseid meteor shower will start peaking from August 11. Best viewed in the early hours just before dawn, Perseids are fast and bright. They leave long streaks of light and colour in their wake as they move through the atmosphere of the Earth.

The Perseid meteor shower peaks this week! Clear and dark skies will help you view them, but you can also watch them on our @NASA_Marshall livestream: https://t.co/WaOPyLFbVL

: @NASAHQPhoto pic.twitter.com/oZrHdoPZL8

— NASA (@NASA) August 10, 2021

So many Perseids sparkle the night sky that you’d see around 50-100 shooting stars every hour if you are in an optimum viewing location. You may be able to see a few from inside the city too, if you’re focused on spotting and lucky.

But before you set out on your celestial viewing session to spot Perseids glittering past in the sky, here’s every thing that you need to know about the stunning annual meteor shower.

What are Perseids and where do they come from?

Originally pieces of space debris, Perseids are meteors which take their shooting form after interacting with the Earth’s atmosphere.  

When such comets visit the sun, they leave behind them a trail of dust and debris. The Earth passes through this trail annually which makes the particles interact with the atmosphere and turn up a spectacular light show for us on the ground.

These debris that become Perseids are broken bits and particles that originate from a comet called 109P/Swift-Tuttle. Discovered by Lewis Swift and Horace Tuttle in 1862, the comet was identified as the reason behind the annual Perseid meteor shower three years later by Giovanni Schiaparelli.

A large comet with a nucleus of 26 kilometers, Swift-Tuttle orbits the sun once every 133 years. The comet was last in the inner solar system in 1992.

The name and the region of the sky

The point in sky from where meteors seem to streak out is called radiant. In fact, names of meteor showers arise from constellations at this radiant point rather than the comets from which they originate.

The Perseids get their name from the Perseus constellation which lies at the radiant point.

What to expect?

Apart from the tens of fast streaking shooting stars in the night sky, the Perseid meteor shower is also famous for creating ‘fireballs’ in the sky. These are relatively bigger explosions where the light and colour can remain visible in the night sky for much longer than an average meteor.

These fireballs are larger pieces or space debris and are much brighter than the regular streaks that you’d witness more often.

The best time to view the Perseid meteor show is in the hours before dawn. Gazers in the northern hemisphere are much better places that their counterparts in the southern hemisphere.
Perseids can be visible in the sky as early as 10 pm at night. In 2021, dates that are your best bet is between August 11 to August 14.