Armagh Astronomers Identify Shooting Stars on the Red Planet

Armagh Observatory astronomers who have been using video cameras to monitor meteor activity, or shooting stars, over Armagh for the past three years, have now extended their reach to meteors on other planets as well.

In work published in the European astronomy journal "Astronomy and Astrophysics", astronomer Apostolos Christou has now reported the first detected signature of a meteor shower on Mars. The shower occurred over four years ago and was seen not by cameras or other optical means but by a NASA spacecraft called Mars Global Surveyor orbiting some 250 miles above the Martian surface, monitoring the state of the planet's upper atmosphere. It appears to have been produced by dust from periodic comet du Toit - Hartley

The probe recorded a short-lived disturbance in the ionosphere of the planet. The ionosphere is a region approximately 50 to 400 kilometres above our heads where sunlight directly hits the atoms and molecules that make up the tenuous upper reaches of the atmosphere and gives them a positive charge, a kind of static electricity. When meteor showers occur, metals in the small dust particles that produce meteors remain in the ionosphere for some time providing additional sources of charged particles.

The ionospheric disturbance at Mars lasted only a few hours but coincided perfectly in time, location and height with the predicted arrival of a stream or trail of meteoroids from comet du Toit - Hartley, a little-known comet with a period of 5.28 years that crosses the orbit of Mars but does not come as close to the Sun as the Earth. The prediction was made possible by the use of sophisticated models perfected by Christou and his colleagues Jeremie Vaubaillon of the Observatoire de Paris in France and Paul Withers of the Centre of Space Physics, Boston University, USA.

The team hopes to discover additional events of this type. This work will ultimately help map out meteor activity during the Martian year and so identify the showers and parent bodies that produce them, which on Mars would rival the spectacular annual Perseid and Geminid displays seen on Earth.

Part of the 1999 Leonid meteor storm
(Credit: Shinsuke Abe and Hajime Yano of the Institute for Space and Astronautical Sciences, Japan).

FOR FURTHER INFORMATION PLEASE CONTACT: Apostolos Christou at the Armagh Observatory, College Hill, Armagh, BT61 9DG. Tel.: 028-3752-2928; FAX: 028-3752-7174; aacarm.ac.uk

Last Revised: 2008 April 7th

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