Bakersfield College

August 7, 2010

Bakersfield Night Sky – August 7, 2010
By Nick Strobel

Tonight and tomorrow night is a gorgeous close grouping of the three bright evening planets, Venus, Mars, and Saturn. All three should fit within your binoculars' field of view. The first star chart below shows the close grouping low in the west. Venus will be the very bright one at the lower right corner of the triangle formed by the three. Saturn will be above Venus on the right side of the triangle and Mars will be the left corner of the triangle. All three will set by 10 PM. About an half hour before sunset, see if you can spot Mercury with your binoculars about 20 degrees (the angle between your pinky and thumb of your spread out hand held at arm's length) to the lower right of Venus. Above the three closely-grouped planets will be the very bright star with an orange tint, Arcturus in Bootes. To the left of the three planets will be the dimmer blue-white supergiant Spica. The blue-white color means it is hotter than the Sun.

Look toward the south to see the summer constellations of Sagittarius, Scorpius, and Ophiuchus. Although Sagittarius is supposed to be a centaur with a bow and arrow ("the archer"), the central brightest part of Sagittarius is called "the teapot". See the second star chart below. Under dark skies, you'll see that the number of stars rises in the direction of Sagittarius. The cloudy part of the Milky Way bulges around Sagittarius. That is because just off the spout of the teapot is the direction to the center of our galaxy, the Milky Way. It also means that in the direction of Sagittarius and Scorpius you will find a number of open star clusters, globular clusters and nebulae that are glowing from the energy of a number of young very hot stars. Some of them are noted in the second star chart below. Above Sagittarius and Scorpius is the dim but large Ophiuchus. Among other things, Ophiuchus' claim to fame is being the thirteenth zodiac sign ignored by the astrologers.

Later in the evening you will be able to see the constellation Perseus rise in the northeast. It will be the locus from where the famous August meteor shower, the Perseids, will appear to originate. The meteor shower will peak in the nights between August 11th and the 13th. Usually there are more meteors visible after midnight because our part of the Earth is facing the direction the Earth is moving in its orbit. All meteors are tiny pieces of material burning up high in our atmosphere. Unlike ordinary meteors that are the little chips of asteroids, the meteors of meteor showers come from tiny dust particles left behind by comets as they pass close to the Sun. The Perseids are the result of the Earth running into the dust trail left behind by the comet Swift-Tuttle. A special bonus for this year's Perseids is that the Waxing Crescent Moon will set early in the evening so the skies will be nice and dark for the few nights before, during, and after the meteor shower peak.

A short time after Venus, Mars, and Saturn set, you will see Jupiter rise in the east so it can keep you company as you watch the meteors. See if you can spot the four largest moons of Jupiter with your binoculars. However, do not use the binoculars for watching the meteors—the wide field of view from using just your eyes will be best for seeing the long trails of the meteors. Also, you will probably notice more of the meteors at the side limits of your view because your eyes have greater sensitivity to faint things near the outer parts of the retina than near the center of the retina (the retina is the back part of your eye that detects light and sends messages to your brain—if your eye was a camera, the retina would be the CCD chip for a digital camera or film in a film camera).

The last star chart below shows the sky an hour before sunrise.

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.

Kern Community College District