In the Sky This Month

Although July offers warm, dry conditions for skywatching, it also provides some of the shortest nights of the year in the northern hemisphere, limiting the hours under the stars. Fortunately, some of the best skywatching sights are visible in the early evening, not long after sunset. Venus reigns as the Evening Star all month, slowly climbing the western sky. Mercury peeks into view below Venus for much of the month, with the star Regulus close to both of them.

July 21: Two Crosses

The Northern Cross is another name for Cygnus, the swan, which sails high overhead on summer evenings. When we look at Cygnus, we’re looking down the spiral arm that contains our own solar system, so we see many amazing celestial objects.

July 22: Vega

Vega, the fifth-brightest star in the night sky, is enthroned at the top of the sky tonight. The name Vega is from an ancient Arabic name that means “swooping eagle.” Vega is in the constellation Lyra, the harp.

July 23: Mars at Opposition

Mars blazes across the sky this week. It rises around sunset and is in view all night. It is brightest for the year, too. In fact, for the next couple of months it will be the third-brightest object in the night sky, after the Moon and Venus

July 24: Mars and Company

The planet Saturn is the bright star-like point of light just below the Moon at nightfall. Its broad, bright rings are tilted into good view, so they reflect a lot of sunlight, enhancing the giant planet’s luster.

July 25: Martian Opposition

Mars is at opposition this week, passing closer to Earth than it will for many years. It is in the southeast as night falls. It looks like a brilliant orange star, outshining all but the Moon and the planet Venus.

July 26: Lunar Eclipse

The Moon will pass through Earth’s shadow tomorrow, creating an eclipse, although it won’t be visible from the U.S. Our consolation is that the Moon will be close to Mars. It looks like a brilliant orange star, to the lower left of the Moon at nightfall.

July 27: Moon and Mars

Mars and the full Moon stick close together tonight. Mars looks like a brilliant orange star, outshining all but the Moon and the planet Venus. It perches close to the lower right of the Moon at nightfall.