We are holding our last Star Party of 2007 tonight (Tuesday 18th December 2007) from 7 to 9 pm and our main theme will be Mars. Ralph has been taking images of Mars with a webcam for several weeks using his own 10-inch Newtonian and, more recently, the NexStar 6 SE. If the skies are clear he will be imaging Mars at the Star Party, showing you how he does it and how he processes the images. If it's cloudy he'll explain it indoors and process some images he took earlier.

We've been impressed with the level of detail the NexStar 6 shows on Mars. SCTs are good all round telescopes but are not optimised for planets. Ralph's images show that they still do a pretty good job. You can see some of his Mars images at http://www.green-witch.com/planetsbyralph.html

Ice Storms

Did you see the news coverage of ice storms in America where branches were falling from trees under the weight of the ice? We used to experience storms like this each winter at the observatory on La Palma. Super-cooled clouds would envelop the mountain top and ice would form instantly on any exposed surface they touched. Black ice would form on the roads and horizontal icicles would grow into the prevailing wind, some a metre or more long.

Two tower cranes collapsed under the weight of ice during the first winter that the builders were on site. After that they removed the cranes when they closed down for the winter. Black ice often made it almost impossible to stand up and I can remember standing still and being blown sideways across the car park, stopping only when I reached the kerb.

Although the winter weather caused us problems it also produced some stunning sights. I'll dig out some photos over Christmas, scan them and put them on our web site. They will show that it's not all sun and sand for astronomers in the Canary Islands.

Inventor of the Laser and SETI at Home

I received an email from Peter Ashwell of Bedford Astronomical Society containing details of the SETI at home project that Dave Eagle had brought to his attention. You may know of this project which seeks to use the spare capacity on your PC to process data in the search for extra-terrestrial intelligence. I noticed that one of the people behind the project is Charles Townes, inventor of the laser.

According to his biography on the Nobel Laureate web site, he came up with the idea of the maser first and produced a working model before going on to invent the laser with his brother-in-law. It doesn't seem long (at least to me) since the laser was routinely described as a solution looking for a problem. Nowadays the laser is in common use and most homes have several. They are used in CD and DVD players, for accurate machining, eye surgery and many other applications, including laser guide stars for astronomy.

There are more details about SETI at home at http://setiathome.berkeley.edu/

Christmas Deliveries

The last day we can send out goods by courier and guarantee delivery before Christmas is Wednesday 19th December. We will continue to send goods out until Friday 21st and the couriers are delivering on Christmas Eve, but if there is a hiccough then we won't be able to sort it out.

The couriers are open for business again on Thursday 27th December which will be the first day they can deliver anything that doesn't arrive before Christmas.

We shall continue to send goods out by First Class mail until Friday 21st but delivery is dependent on Royal Mail.

We close at the end of the day on Saturday 22nd December and open again on Wednesday 2nd January 2008.

Looking South at 10 p.m.

Three constellations run down our meridian, starting with Perseus almost overhead, then Taurus and Eridanus. Comet Holmes is still visible with binoculars in Perseus and continues to grow and appears larger than the Moon.

The Pleiades in Taurus are on the Meridian and are always worth looking at through binoculars. Most people can see six stars with the naked eye but sharp-eyed observers may see more. There are around 500 stars in the cluster and they are relatively young, hot stars. Photographs show nebulocity around the brighter stars, especially Merope where the Merope Nebula is the most prominent. The nebulocity is a cloud of gas that the cluster is passing through by chance, rather than the remnants of the cloud from which they formed.

While you have your binoculars out to look at Comet Holmes and the Pleiades, why not browse the other open cluster in Taurus, the Hyades. A little lower and to the left, it is much more open but is still a lovely sight. Aldebaran, the eye of the bull is a prominent red giant, a star that is burning hydrogen and helium in its outer shell rather than its core. Its ultimate destiny is likely to be as a white dwarf.

If you need a pair of binoculars for astronomy then consider the Bresser 9x63s at 99.95 pounds. We are still offering them with a free copy of Stargazing with Binoculars by Robin Scagell and David Frydman. This is a new book which we recommend highly for anyone who wants to explore the night sky with binoculars.

Eridanus is a long, faint constellation stretching well below our horizon. In mythology it is said to represent the River Po into which Phaeton plunged when struck by a thunderbolt while driving the Sun Chariot. Overshadowed by its near neighbour, Orion, Eridanus is not very prominent but you might like to hone your star-hopping skills by tracing the line of the 'river' using binoculars.

And finally...

We wish you a very Happy Christmas and a prosperous New Year from all the staff at Green Witch. It has been a pleasure to serve you in 2007 and we look forward to seeing you again in 2008.

Clear Skies and Best Wishes

Neil

www.green-witch.com
www.arizonaskyvillage.co.uk
www.astroblast.org.uk