Get ready for a month of shooting stars

By Jennifer Ennion 21 March 2016
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Earth is about to make its annual pass through the tail of Halley’s Comet.

AUSTRALIAN SKY-GAZERS can expect to see plenty of shooting stars next month, when Earth passes through the tail of Halley’s Comet.

The annual occurrence is known as the Eta Aquarids meteor shower, and this year observers will have prime viewing thanks to the shower coinciding with a New Moon.

The Eta Aquarids will begin around 20 April and continue until about 21 May. Astronomers say the best time to see the shower, or “shooting stars”, will be in the middle of the event, on 6 and 7 May, when the New Moon occurs. When this happens, the sky will be at its darkest, as the moon moves between the Earth and Sun and is hidden from view.  

One to two meteors every few minutes

Dr Brad Tucker, an astrophysicist at Australian National University in Canberra says the Eta Aquarids will mostly be visible in the Southern Hemisphere, where observers can realistically expect to see one meteor every two to three minutes in a dark sky, particularly around the 6 May peak.

“Here, in the Southern Hemisphere (the shower is) nice and bright, high in the Eastern Sky,” Brad says.

However, those who live in a city, where tall buildings, trees and lights will obstruct their view, will see fewer meteors. The best places to go for viewing are dark, open areas, such as parks and paddocks.

Astrophotographers and anyone else interested in catching the sight should set their alarms. Brad says the prime time for viewing is during the early morning hours, from about 3am to dawn. This is when the relevant field of sky is above Earth’s horizon.

Old comet debris

Observers in the Northern Hemisphere may get lucky, but only if they live in southern regions, such as the US state of New Mexico, Brad adds. Even then, the shower will be low on the horizon, where the view will be obscured by clouds and light pollution.

The Eta Aquarids gets its name from its approximate origin, in the constellation Aquarius, near the Eta Aquarii star. A meteor shower occurs when Earth passes through the debris of an old comet, such as Halley.

“It’s rocks and ice that have been burnt off or fallen off the comet’s core – the nucleus – and it’s kind of left this big trail,” explains Brad.

“So when we go on our yearly orbit around the Sun, we cross through it at the same time, at the same area.”

The debris of Halley’s Comet creates two meteor showers every year. The Eta Aquarids is the first to occur, with the Orionids taking place in October.