The Moon will reach last quarter early tomorrow as it lines up at a right angle to the line connecting Earth and the Sun. The Sun will illuminate half of the Earth-facing lunar hemisphere, making it look as if some cosmic giant had sliced the Moon down the middle.
Weekly Stargazing Tips
Provided by StarDate.org. Unless otherwise specified, viewing times are local time regardless of time zone, and are good for the entire Lower 48 states (and, generally, for Alaska and Hawaii).
March 21: Last-Quarter Moon
March 22: Pyxis
If you have a compass, let it point you to the southeast as night falls for Pyxis, the celestial compass. It's a short line of faint stars, aiming toward the remnants of the Argo - the ship that carried Jason and the Argonauts. Pyxis represents its compass.
March 23: Lost Cluster
At 2,500 light-years away, M48 is one of the most distant star clusters of its type visible to the eye. At nightfall, it's high in the southern sky, far to the upper left of Sirius, the night's brightest star. Binoculars reveal some of M48's individual stars.
March 24: Virgo Cluster
Our home galaxy, the Milky Way, belongs to a small cluster of galaxies known as the Local Group. But most galaxies reside in more impressive clusters. The closest of these is the Virgo Cluster, centered in Virgo, which steps up the eastern sky this evening.
March 25: Cosmic Voids
Boötes the hunter climbs into view in early evening, marked by the bright yellow-orange star Arcturus, which is low in the east by 9 or 10 p.m. One of the largest "voids" in the universe, an empty region known as the Great Nothing, stretches to the upper left of Arcturus.
March 26: Messier 3
Messier 3 is a globular star cluster - a dense ball a few hundred light-years across. Its stars are among the oldest in the galaxy. The cluster is in Canes Venatici, the hunting dogs, and is low in the east-northeast in early evening. It's easy to see with binoculars.
March 27: Splintered Argo
Argo, the ship of Jason and the Argonauts, sails across the south tonight. It originally was a single constellation, but astronomers broke it into four smaller ones: Carina, the keel; Vela, the sail; Puppis, the poop deck; and Pyxis, the compass.