8 Nov 2010
Professor Alan Fitzsimmons from the Astrophysics Research Centre (ARC) will be talking about comets in our Solar system on the forthcoming episode of The Sky At Night on BBC Television.
Presented as usual by Sir Patrick Moore, it has been timed to mark the successful flyby of comet Hartley 2 by NASA's Deep Impact spacecraft. The episode reflects on what we know and what we don't know about these icy bodies orbiting our Sun.
The show will be shown in Northern Ireland on BBC1 on Tuesday 9th November at 12:25am, BBC4 on Tuesday 9th November at 7:30pm, and again on BBC2 on Saturday 13th November at 4:40pm.
Prof. Fitzsimmons said "It was a great experience to chat with Sir Patrick and others about comet Hartley 2. Even better was going out into Patrick's garden and seeing the comet myself though a small telescope".
Alan's co-interviewee is Dr. Stephen Lowry from the University of Kent, who received his PhD in cometary studies at Queen's University before going to work at NASA for several years.
Comets like Hartley 2 are warmed by the Sun each time they come into the inner solar system. The frozen water and carbon monoxide on the surface is released as gas, taking with it small grains of rock and other material. The more the comet releases, the brighter the comet appears.
"The last really bright comet seen from Northern Ireland was comet Hale-Bopp in 1997." said Prof. Fitzsimmons. "Although Hartley 2 needs a telescope to see it, we never know when the next really bright comet will be discovered heading into the inner Solar system to give us a great show".
ARC has a long-standing research programme into comet and their rocky cousins the asteroids. Using large ground-based and space-based telescopes, ARC astronomers measure the size, shape and compositions of these objects.
Members of ARC have previously studied comet impacts on the planet Jupiter, discovered a new type of comet tail, and discovered comet-like objects orbiting the Sun beyond the planet Neptune in the Edgeworth-Kuiper Belt.
The Sky at Night started in 1957, and is the world's longest running television programme with the same presenter.