Stellar Vista Observatory Sky Report
Jan.10 – 16
The Sky Report is presented as a public service by the Stellar Vista Observatory, a nonprofit organization based in Kanab, Utah, which provides opportunities for people to observe, appreciate and comprehend our starry night sky. Additional information is at www.stellarvistaobservatory.org. Send questions and comments to [email protected]
With Venus gone but Mercury trying to take its place we’re left with three planets in the evening sky, but only Jupiter will be easy to spot. It’s the brightest thing in the sky, other than the sun and moon, and it’s low in the southwest after sunset, setting three hours after the sun.
To the lower right of Jupiter, at the 5 o’clock position, are Saturn and Mercury, but they’re so low – and they’re much fainter — that you will have trouble seeing them. Look 40 minutes after sunset. Most of this week Mercury is about 4 degrees to the lower right of Saturn, and the two are equal magnitude. Use binoculars.
This is about the final week to see Saturn and we lose Jupiter next month. These two planets set four minutes earlier each night, or a half-hour earlier each week, not because of anything they’re doing, but because of what the earth is doing, as was explained in an earlier Sky Report. (Sky Reports are archived at this website.) Basically, the earth is orbiting the sun quicker on an inside path, and we’re leaving them behind.
The planets Uranus and Neptune are out this evening too, and you can see them in a small telescope if you know precisely where to look. This too was described in a recent Sky Report.
The moon is near the Pleiades on the 12th and the Hyades on the 13th, two prominent star clusters easily visible to the unaided eye. Both are in Taurus, the Bull. You can see hundreds of star clusters with even a small telescope but these two are the best known because they’re so bright and so compact. All the stars in a cluster were born together and are the same age; they’re siblings. The stars of the Pleiades are roughly 100 million years old (the same age as the Rocky Mountains) and the Hyades 600 million years old, and gravity holds them together. Gradually individual stars drift away, one by one, and the clusters disperse. Uncle Google can tell you more about each.
If you have a telescope and an astronomy app for your smartphone or tablet, try to find Comet Borrelly. It’s slowly moving through Cetus and is expected to reach maximum brightness at ninth magnitude early this month. The nucleus is shaped like a bowling pin only 5 miles long, and it’s 110 million miles from earth.
Caption: this view of the ice and rock nucleus of comet Borrelly was taken from a NASA spacecraft that flew past it in 2001.