Venus and Jupiter, the brightest points of light in the night sky, dominate the early evening hours for most of the month. They are especially close together as the month begins, but remain close until late July. By the time they set, the two signature constellations of summer, Sagittarius and Scorpius, are in good view in the southern sky. The brightest stars of Sagittarius form a teapot, while those of Scorpius form the curved body and barbed tail of a scorpion.
This Week's Stargazing Tips
July 31: The Swan
The swan climbs high across the southern sky on summer nights. It’s marked by its bright tail, the star Deneb, which is high in the east-northeast at nightfall. The swan’s body angles to the upper right of Deneb, while its wings flank the swan’s body.
August 1: Lammas
August 1 is the date of the ancient English festival Lammas. It is a cross-quarter day, which falls roughly half-way between a solstice and an equinox. Lammas marked the end of summer, not its mid-point.
August 2: 61 Cygni
After the Sun, the first star whose distance was accurately measured was 61 Cygni. It is part of Cygnus, the swan, which soars high overhead this evening. 61 Cygni is about 11 light-years away. It appears fairly close to Deneb, the swan’s tail.
August 3: Delta Cephei
Delta Cephei is one of the leading lights of Cepheus, the king, which stretches from north to northeast at nightfall. The star is unstable, so it pulses in and out like a beating heart. Astronomers recently discovered that it has a small, close companion star.
August 4: Moon and Uranus
With binoculars, you can spot the planet Uranus before dawn tomorrow, above the Moon. It forms a tight triangle with two slightly brighter stars in the constellation Pisces. All three should fit in your binocular field of view.
August 5: Pegasus
Pegasus, the flying horse, rises in the east in early evening. Look for a large square of four bright stars known as the Great Square. The stars that represent the horse’s head and forelegs stretch above and to the right of the square.
August 6: Last-Quarter Moon
The Moon is at last-quarter tonight. The name is a bit misleading, because sunlight illuminates half of the visible lunar disk. The “last-quarter” moniker means that the Moon has completed three quarters of its monthly cycle of phases.
Check last week's tips if you missed a day.