New Delhi, Oct 21 — Skywatchers in India have a date with Halley's Comet tonight — not the comet itself, which returns only in 2061, but the trail of debris it left behind. The Orionid meteor shower peaks on the night of October 21-22, NASA lists, as Earth passes through the stream of particles shed by the famous comet.

When and where to look in India: The Orionids are a late-night shower. From India, the radiant — the point in the constellation Orion from which the meteors appear to stream, near the reddish star Betelgeuse — rises around 10-11 pm and climbs higher through the night, The Times of India reported. The favourable viewing period in India runs from roughly 3:30 am to 5:15 am IST on October 22, after the Moon has set and before morning twilight, according to the report. No telescope or binoculars are needed; the naked eye, a dark spot away from city lights, and 20-30 minutes for the eyes to adjust are enough.

What to expect: NASA gives a rate of about 10 to 20 meteors per hour under dark skies at the peak, with the meteors entering the atmosphere at around 66 kilometres per second, Digit reported, citing NASA. A bright waxing gibbous Moon will wash out fainter streaks while it is up, the American Meteor Society notes, which is why the hours after moonset are the practical window this year. The shower remains active from October 2 to November 7, so a cloudy peak night is not the last chance.

Sources: NASA (skywatching guidance, reported by Digit and Taaza Khabar), The Times of India / Education Times, American Meteor Society.