A pale green comet is approaching Earth in one of the closest astronomical encounters of its kind in centuries. “Comet Hartley 2” promises to be the brightest comet of 2010. If you travel far from city lights, you may be able to see the comet near the Name A Star Live constellation Cassiopeia in early October.
Comet Hartley 2, a small comet about ¾ to 1 mile (1.2 to 1.6 km) in diameter, was discovered in 1986 by Malcolm Hartley, an Australian astronomer. It orbits the sun about every 6.5 years, and on October 20 the comet will make its closest approach to Earth since its discovery. In this case, “close” means 11 million miles, or 17.7 million kilometers. However, as the Moon will be close to full at that time of the month, your best chance of viewing the comet at a convenient time of night will actually be in early October, when the Moon will not be a factor. Note that even relatively “bright” comets like this one can be difficult to see as their light is ‘spread out’ compared to the light of a star, for example. So be sure to find a really dark spot to get a good look through a pair of binoculars or a telescope.
A NASA spacecraft called “EPOXI” (formerly known as “Deep Impact”) will fly past Comet Hartley 2 in early November and take photos of the comet’s nucleus.
Seeing planets this month
The mighty planet Jupiter dominates the night sky this month. Jupiter is the bright point of light you’ll see toward the east after sunset: It’s easy to spot.
If you’re away from city lights and have a good telescope or a good pair of binoculars, you may even see the planet Uranus near Jupiter. It will appear as a pale green dot nearby, just to the east of Jupiter.
Venus and Mars are low on the western horizon around sunset in early October. Mars will be just to the north of Venus. Both of these planets will set shortly after sunset. Venus will become increasingly difficult to see as the month progresses.
Finding your star in the night sky
Stars are located within constellations, which are just areas of the night sky. Scorpius, Aries and Taurus are examples of constellations. Your Name A Star Live Star Certificate displays the name of your constellation.
You can use our online World Constellation Guide to determine if you can see your constellation during the evening hours (between sunset and midnight). Of course, you’ll need a telescope to see your star. (That’s why we include the SLOOH online telescope experience in our Deluxe, Framed and Ultimate Gift Sets!) But you can see your constellation without the use of a telescope.
You can also find your constellation by using our Virtual Planetarium™ astronomy software. A planisphere is another useful device.