In the Sky This Month

Aquila, the eagle, is in the eastern sky at nightfall. Its brightest star, Altair, is at the lower right corner of the Summer Triangle. A star named Tarazed is just above Altair. Tarazed is a giant star that is nearing the end of its life.

The Summer Triangle is well up in the eastern sky at nightfall, and passes directly overhead after midnight. Vega, its brightest point, is at the top of the triangle in early evening. Deneb is the left point, with Altair to the lower right.

The gibbous Moon has a famous companion tonight: the planet Mars. It is to the lower right of the Moon as they climb into good view, around midnight, and almost directly below the Moon at first light tomorrow. Mars looks like a bright orange star.

The planet Mars is growing brighter by the day. It’s in good view in the southeast by midnight, and looks like a bright orange star. Tonight, it stands to the lower left of the Moon.

Arcturus, the leading light of Bootes, the herdsman, stands high in the south as twilight turns to darkness. It is the brightest true star in the sky during the evening hours, so it’s hard to miss. It shines yellow-orange.

Saturn lines up opposite the Sun today, so it rises at sunset and is in view all night. A planet is closest to Earth at opposition, so it shines brightest for the year. Tonight, Saturn will stick close to the Moon.

Delphinus, the dolphin, glides through the Milky Way on summer evenings. Tonight it rises not long after sunset and arcs high overhead. Look for it below the Summer Triangle, which is well up in the east a couple of hours after darkness falls.

Antares, one of the brightest stars in the night sky, is not far to the lower right of the almost-full Moon at nightfall. Antares is near the middle of the curved body of Scorpius, which is in the south-southeast.

The planet Saturn is low in the southeast as night falls, and looks like a bright star. Its luster is dimmed by the gibbous Moon, far to Saturn’s upper right. Even so, Saturn outshines all but a few other objects in the night sky, so it’s hard to miss.

Brilliant Jupiter stands to the lower right of the Moon as night falls. Although it looks like a bright star, it’s actually the largest planet in the solar system. It is about 11 times Earth’s diameter and more than 300 times Earth’s mass.