The sky tonight - October 2007

All of the objects mentioned in last month's guide are still visible throughout October.
However, Jupiter is getting increasingly difficult to observe, now setting just 2 hours after sunset. Look low towards the south-west about one hour after sunset, and it is the brightest object in the sky. Take a look through binoculars, and see if you can spot the four bright Galilean moons that orbit around the planet.
Although we are losing Jupiter until next year, we are gaining Mars, as it wanders across the sky to become more easily visible. By the end of October, Mars is rising in the east as early as 22:30 local time.
Be careful not to get Mars confused with the red giant star Aldebaran, which rises just one hour earlier. Just above Aldebaran is a small cluster of a few hundred stars called the Pleiades. The cluster is also known as the seven sisters, because the brightest seven are visible to the unaided eye within an area the same size as the full moon.
Aldebaran lies about 12 degrees below the Pleiades star cluster - that is the size of your out-stretched hand at arms length - while Mars is far off towards the bottom left of both in the evening eastern sky.
At midnight, another red giant star rises below Aldebaran and to the right of Mars - the bright red giant Betelgeuse.
Betelgeuse is part of the constellation of Orion - the classic winter constellation. Currently, Orion is rising at midnight, but by the end of November, it will have risen by 10pm, all thanks to the Earth moving around the Sun to get a better view of this wonderful constellation! More about Orion next month...