See the moon turn blood red

On 9 January there will be a full lunar eclipse, and a group of space nuts are planning to video the whole thing and stream it live over the Net.

Their video of the event is likely to be quite spectacular - weather permitting - since they will be viewing it at dawn when the rays of the sun can make the moon appear red.

There are usually two or three full lunar eclipses a year, making them rarer than solar eclipses. However, as my old astrophysics tutor used to tell us, the lunar eclipses can be seen across the globe, while a solar eclipse is a localised phenomenon, so it seems as though they happen less often.

For those who are newer to the whole eclipse business, a lunar eclipse occurs when the moon passes into the earth's shadow. How much the moon is dimmed depends on whether it passed through the penumbra or the darkest part of the shadow, the umbra.

As well as providing a pretty spectacle for earth bound star-gazers, lunar eclipses have also caused problems for space scientists. Two years ago NASA was concerned that the earth's shadow could interrupt the power supply to the Lunar Prospector, which relied on solar panels to recharge its batteries.

The eclipse will be photographed by zoom lenses attached to a telescope with a video camera - no mean feat as anyone who has ever tried to take photographs through a telescope can tell you. Viewing software such as RealPlayer 8, Windows Media Player 7, or QuickTime Player 4 are required to see the live eclipse

The guys have put together a site about lunar eclipses and, although some parts are still under construction, it is looking good. There are some nice little animations and a couple of pages of very accessible information about the phenomenon.

Check their site out at Live-Eclipse.org, and you can access more astronomical data about the eclipse here. ®