This is Dudley Observatory’s Skywatch Line for Friday, March 1 through Sunday, March 3, written by Sam Salem.
On Friday, the Sun rises at 6:32am and sets at 5:45pm; the waning crescent Moon rises at 3:43am and sets at 1:09pm. Before sunrise on Friday, watch the lunar crescent lying roughly three degrees to the right of Saturn. On Saturday before sunrise, see the pairing of the crescent Moon and Venus in eastern sky. Crescent Moon and Venus are very bright that you might be able to see them shortly after sunrise.
Two other planets join up with Venus in the morning sky. Jupiter shines above Venus, whereas Saturn, the dimmest of these three, shines in between Jupiter and Venus. Jupiter gleams at magnitude –2.0 and rises shortly after 2:10am. Next up is magnitude 0.6 Saturn, which clears the southeast horizon around 4:00am, followed half an hour later by magnitude –4.1 Venus. While Jupiter and Saturn are at the start of their current apparitions and will climb a little higher each morning, Venus is very gradually sinking lower and lower.
Take advantage of evening hours over this moon-free weekend to do some deep-sky observing. Gemini’s open cluster, M35, at 5.1-magnitude, is easy to find, as it’s located just above the westernmost foot of the Twins stars, marked by 2.9-magnitude Mu (μ) and 3.3-magnitude Eta (n) Geminorum. Tripod mounted 10×50 binoculars are powerful enough to show a few individual cluster members in M35. Use a telescope to resolve many more stars. Try to spot M35’s celestial neighbor, the 8.6-magnitude cluster NGC2158. It’s not easy to catch in binoculars. With a small scope, and a reasonably dark sky, you will have no trouble pulling in little NGC2158. The two clusters are physically similar but they look quite different because one is much nearer the Earth than the other. M35 is the closer object, at roughly 2,800 light-years. It’s only one-fifth the distance of NGC2158.
Look for the Big Dipper in the northeast sky at any March evening. This star pattern is one of the most noticeable patterns from Northern Hemisphere locations. It is part of the constellation Ursa Major, the Greater Bear. Find the Big Dipper then look for the two Hunting Dogs seen by the ancient stargazers to be nipping at the Bear’s heels. The Hunting Dogs are a separate constellation, tiny Canes Venatici. You’ll need a dark sky to see these two little stars snuggled in the arc of the Big Dipper. These two stars were originally called by the names Chara and Asterion. But the eastern star is now called Cor Caroli, or Heart of Charles, named for the patron king of the Polish astronomer Johannes Hevelius who created this constellation in 1690. The most famous object in this region of the sky is M51, the Whirlpool Galaxy. Unfortunately, this galaxy is difficult to glimpse with binoculars. However, it is beautiful when seen through telescopes and appears dramatic in photographs. There’s another faint object at the extreme edge of Canes Venatici that your binoculars should pick up. This object is the globular star cluster M3. In binoculars M3 looks as a dim blur of light. In a dark sky, M3 is relatively easy to find. It lies almost midway between the bright stars Arcturus and Cor Caroli. Follow the arc of the Big Dipper’s handle in order to locate Arcturus.