Bakersfield Night Sky - September 4, 2010

Bakersfield Night Sky - September 4, 2010
By Nick Strobel

Venus continues to get slightly brighter (if you can believe it can get any brighter!) low in the west in the early evening sky. It is so bright that it is possible to see it in broad daylight if you know right where to look and can block out the Sun with a building. In a telescope you will Venus' crescent lengthening and getting thinner as it catches up to us in its faster orbit. When the sky gets darker, you will be able to see the bright star Spica in Virgo to the right of Venus and above Spica and slightly to the right will be orange-red Mars. All three may just barely fit within the field of view of your binoculars. I show their positions in the second chart below---try to observe them before 8 PM.

Ah, Mars! I feel a little deprived since I didn't get the "Mars as big as the Full Moon" email that comes out every August 20th or thereabouts. The email started in 2003 when we had an exceptionally close passage by Mars. The email that got passed around then and every August thereafter, left out a key phrase from the original message that said that Mars would appear as large as the Full Moon when viewed through a telescope at 75-power magnification. The telescope part continues to be conveniently left out as the email circulates the internet. Another thing to keep in mind about Mars is that we pass close to it about every 26 months (780 days) because while we are moving in our orbit, Mars is also moving. Therefore, it takes us more than a year to pass it from the previous time.

Later in the night, very bright Jupiter will rise in the east. Look for it below the "Great Square" of Pegasus among the dim stars of Pisces. The first chart below shows its position for 9:30 PM tonight. Also shown is the much dimmer Uranus up and slightly to the right of Jupiter. That one will probably require binoculars to see but those of you with very good eyes and very dark skies might just barely pick it out without the binoculars. To the left of Pegasus is the Andromeda constellation. In Greek mythology, Andromeda was the princess rescued by Perseus. Pegasus was also in that story so Andromeda is situated between Pegasus and Perseus. Both Andromeda and Pegasus are upside down on our sky. Above the second star in the top string of Andromeda is a fuzzy patch that is the farthest thing you can see without a telescope or binoculars—the Andromeda Galaxy over 2.5 million light years away. That means we are seeing it as it was over 2.5 million years ago. The Andromeda Galaxy is undoubtedly still there shining since galaxies change on timescales of many tens of millions to hundreds of millions of years.

This past week the Moon has been visible in the morning sky getting closer and closer to the Sun and getting thinner as it does so. Tomorrow morning, you will see it as a very thin crescent rising about 3 hours before sunrise (see the third chart below). By next Saturday, the Moon will have moved to the other side of the Sun on our sky and it will be a thin waxing crescent facing the Sun and to the left of Venus in the early evening sky.

The BC Ticket Office is now selling tickets for this fall's planetarium shows. The first show is "Oasis in Space" on Thursday, September 30th. Get your tickets in advance!

If you want to find out more about what the planets are like, check out my Astronomy Notes site. The content of the planets section of the site was greatly expanded earlier this summer.

Want to see more of the stars at night and save energy? Shield your lights so that the light only goes down toward the ground. Visit the Dark Sky International website for more info.
Nick Strobel
Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website