In the Sky This Month

Mars is a third of the way up the western sky at sunset and looks like a fairly bright orange star. It’s to the upper left of Venus, the brilliant Evening Star, by a little more than the width of your fist held at arm’s length.

The Great Pyramid of Khufu, the largest of the pyramids of Giza, was aligned with the help of Thuban, the North Star at the time of its construction. And the pyramid contains a shaft that aims at Orion’s Belt, which represented the destination for the dead king.

The Moon is at first quarter at 10:54 p.m. CDT. A quarter Moon lines up at a right angle to the line between Earth and the Sun, so sunlight illuminates half of the lunar hemisphere that faces our way.

Look for Jupiter, the largest planet of the solar system, close above the Moon at dawn tomorrow. It looks like a brilliant star. Through binoculars, Jupiter’s big moons look like small stars lining up quite near the planet.

The planets Jupiter and Saturn line up near the Moon in the wee hours of tomorrow morning. Saturn is close to the upper right of the Moon, with brighter Jupiter farther to the left of the Moon.

The Moon climbs into view after midnight with the bright planet Saturn to its left as they rise, and to the upper left at first light. The Moon is in its “gibbous” phase, so the Sun lights up more than half of the hemisphere that faces our way.

Mercury and Venus appear to almost touch each other. The planets are low in the northwest about 30 minutes after sunset. Venus, the Evening Star, is by far the brighter of the two. They set by the time the sky gets dark.

The scorpion skitters across the southern sky. Its tail clears the southeastern horizon by midnight, and the scorpion remains visible for the rest of the night. Its brightest star is Antares, in the middle of the scorpion’s curving body.

Look low in the east early this evening for three major stars of summer. In the southeast is Antares, the bright heart of the scorpion, close to the Moon. Scan far to its left for the bright white stars Vega, in the harp, and Deneb, in the swan.

The Moon slips through Earth’s shadow early tomorrow, creating a total eclipse. From the eastern U.S., the Moon will set before the total eclipse begins. The western U.S. will see all of the total eclipse and all or most of the partial eclipse.