Bakersfield Night Sky – October 2, 2010
By Nick Strobel
Although Venus is getting as bright as it can get in the evening sky, it is also getting harder to see as it gets closer to the Sun. Although Venus sets about an hour after the Sun, it is already less than ten degrees above the western horizon at sunset. There is a lot of twilight sky glow washing it out somewhat. By mid-month Venus will be too hard to see in the sunlight glare as Venus passes by us in its faster orbit. In early November Venus will be visible in the pre-dawn sky. Up and to the right of Venus (about half of a clenched fist held at arm's length away from Venus) is the dimmer orange-red Mars. Mars will also be too hard to see in the last half of the month as it passes behind the Sun from our viewpoint. After that we'll need to wait until next spring to see it in the early morning sky without binoculars.
Jupiter dominates the evening sky tonight shining in the southeast brighter than any other star in the night sky. It will be visible all night long. Over the past couple of months, it has been undergoing retrograde motion (going backward from its usual motion with respect to the stars). It will stop moving backwards in the last half of November. Although Jupiter is among the stars of Pisces, the stars of Pisces are too dim to see with all of the light pollution. Therefore, you will need to use the brighter stars of the "Great Square" of Pegasus further up and to the left of Jupiter to trace its motion. See the first star chart below. Next to it, the much dimmer (telescope required!) Uranus has also been doing a retrograde loop on the sky. However, because Uranus is much further away, its loop is much smaller than Jupiter's. Last month Jupiter passed by Uranus and it will do so again in January.
The Moon's phase tonight is a Waning Crescent so it is a thin crescent rising in the early pre-dawn hours around 2:30 AM. It will be below the Beehive Cluster in the dim zodiac constellation of Cancer. With the Moon rising so late in the night, you might be able to see a faint smudge near the "W" of Cassiopeia in the northeastern sky in the evening. That is Comet Hartley 2. You'll need binoculars to see it tonight but in the next couple of weeks, the comet should be bright enough to see without binoculars in a dark sky free of light pollution. See the Comet Hartley 2 finder chart below. On November 4th, NASA's Deep Impact spacecraft will fly to within 600 miles of the comet nucleus to give us a close-up look. Deep Impact was the one that smashed a projectile into a Comet Tempel 1's nucleus back in July 2005. The spacecraft's mission has been renamed "EPOXI" so use that name when doing a search on the NASA website.
On October 9th, the Moon will be a very thin Waxing Crescent visible between Venus and Mars l-o-w in the southwest just after sunset. On October 16th, the night of the last monthly Kern Astronomical Society public star party for the fall season, the Moon will be among the stars of Capricornus. The public star party will be at Barnes and Noble from sunset to around 10 to 10:30 PM depending on the foot traffic (and weather, of course!).
Last month on the autumnal equinox, the Moon was in full phase above Jupiter and several people told me how beautiful that looked. This month the Moon will pass Jupiter on October 19th and it will be a Waxing Gibbous phase. Although our time period of a month comes from the phase cycle of the Moon, at 29.5 days, the phase cycle is slightly less than the set 30-days or 31-days of our calendar months.
Two days after the Moon passes Jupiter (i.e., on October 21st), the William M Thomas Planetarium will be showing "Dawn of the Space Age". This is a popular show. Last month's show for the general public was sold out a few days before show time, so if you want to see the October show, get your tickets as soon as you can from the BC Ticket Office.
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. See www.darksky.org for how.
Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website www.astronomynotes.com