In the Sky This Month

The Moon is new today as it crosses the imaginary line between Earth and the Sun. It is hidden in the Sun’s glare, but soon will return to view as a thin crescent in the western sky shortly after sunset.

The planets Venus and Mercury are huddling close together. Venus is the brilliant Evening Star. Their closest approach is tonight, although they will remain close together for several nights.

Look for Mercury below Venus, the brilliant Evening Star, after sunset. They set by about 10 p.m. The planets will be closer together tomorrow night, with Mercury climbing just above Venus by Friday. The crescent Moon will join them this weekend.

Four stars in the constellation Corvus, the crow, form a small lopsided box that resembles a sail. It’s in the south at nightfall. The star at the top left corner of the sail is Delta Corvi. Clockwise from there, the other stars are Gamma, Epsilon, and Beta Corvi.

The constellation Boötes is high in the east at nightfall. Its brightest star is brilliant yellow-orange Arcturus. To the left of Arcturus is fainter Izar. A telescope reveals that Izar is really two stars, one of which is orange, the other blue-white.

The four stars at the center of Hercules form a lopsided square called the Keystone. It is in the east-northeast at nightfall. Its brightest star, at the upper right, is Zeta Herculis. Moving clockwise, the other three are Epsilon, Pi, and Eta Herculis.

Cassiopeia the queen stands low in the north at nightfall and wheels up the northeast during the night. Its brightest stars form a pattern that resembles a letter W.

The brightest stars of the constellation Ursa Major, the great bear, form a pattern known in the United States as the Big Dipper. Other parts of the world, however, see the pattern as a plow. The plowman is the next constellation over, Boötes.

The planet Mars stands above the Moon early tomorrow. It looks like a fairly bright orange star. Mars and Earth are moving closer together now, with closest approach in October. As a result, Mars is getting a tiny big brighter each night.

Mars stands near the Moon the next couple of mornings. The planet looks like a fairly bright orange star. It is to the left of the Moon at first light tomorrow and a bit closer above the Moon on Friday.