In the Sky This Month

Several constellations of the zodiac stretch across the southern sky at nightfall. Leo nose dives toward the western horizon, Virgo stretches to its upper left, Scorpius is due south, and Sagittarius is climbing in the southeast.

The Summer Triangle highlights the eastern sky as darkness falls. The triangle’s brightest star, Vega, stands highest in the sky. Deneb marks the lower left corner of the triangle, with Altair at the lower right.

Lupus, the wolf, is low in the south as darkness falls. The faint constellation represents an ancient king who was punished for trying to trick Zeus, the king of the Greek gods.

A partial lunar eclipse will be visible across Africa, Antarctica, and most of Asia, Europe, and Australia today. North America will have to settle for an uneclipsed full Moon in the night sky.

The Moon has a close, bright companion tonight: the planet Saturn. It is named for the Roman god of agriculture and plenty, who was honored with one of the most important festivals of the year.

Delta Lyrae is a prominent double star in Lyra, the harp. Binoculars reveal that one star looks red, while the other is blue. Although the stars appear close together, they are separated by more than 100 light-years.

Look for Jupiter, the largest planet in the solar system, close to the Moon tonight, shining like a brilliant star. The fragments of a shattered comet battered Jupiter 25 years ago this month, creating blemishes that were visible for months.

Antares, the brightest star of the scorpion, stands below the Moon as night falls this evening. Brighter Jupiter, the largest planet in the solar system, is about the same distance to the lower left of the Moon.

The Dumbbell Nebula, a colorful bubble of gas expelled by a dying star, is in Vulpecula, the fox, which is high in the east at nightfall. The nebula is about halfway between Deneb and Altair, the stars that mark the bottom of the Summer Triangle.

One of the favorite constellations of summer soars high across the sky this month: Cygnus. It stretches across the east and northeast at nightfall. Its brightest stars form the outline of a graceful swan, soaring through the Milky Way.