July opens with four morning planets—Venus, Mars, Jupiter, and Saturn—strung out in that order from northeast to south. By month’s end, Saturn will be moving into the southwest and both Saturn and Jupiter start rising before midnight.
Earth laps Saturn in the orbital race on August 14, and we catch up to Jupiter on September 26. As for Mars, it’s getting steadily brighter, but we won’t lap it until early December. If you’re unsure which object is Mars—or even if you’re quite sure—you may want to get outside just as the day starts to break on July 22, when a waning crescent moon will be about midway between the Red Planet and the lovely Pleiades star cluster.
Venus lingers very low in the east to northeast, but with the morning sky staying dark longer each day, we don’t have to get up quite so early to catch it.
In the evening sky, Scorpius scrapes the southern horizon at nightfall. On July 10, a waxing moon will be close to the scorpion’s heart, the gigantic red star Antares. High above Scorpius shine two brilliant stars. To the west, Arcturus anchors the kite-shaped constellation Bootes, the herdsman. To the east, Vega ornaments the smaller constellation Lyra, the lyre. Vega is also the brightest of the Summer Triangle of stars, which also includes Deneb, in Cygnus, the swan; and Altair, in Aquila, the eagle.
July’s full moon will be another big, luminous supermoon. It gets its large size by arriving on July 13, the same day it swoops closest to Earth in this lunar cycle.
On July 4, Earth reaches aphelion, its farthest distance from the sun: 94.5 million miles. On that day we’ll be moving most sluggishly in our orbit—18.2 miles per second, compared to 18.8 miles per second when we’re closest to the sun.
July 6—First Quarter Moon
The Moon is one-quarter of its way through its orbit around the Earth, which makes half the Moon illuminated and half dark from our perspective. This is the best time of the month to see the Moon’s surface features like craters and mountains through binoculars or a telescope.
July 13—Full Moon
The Moon is located on the opposite side of the Earth as the Sun and the side we see is fully illuminated.
July 20—Third Quarter Moon
This phase occurs when the Moon is three-quarters of the way through its orbit around the Earth.
July 28—New Moon
The Moon is located on the same side of the Earth as the Sun and is not visible in the night sky. This is the best time of the month to observe faint objects like galaxies and star clusters because there is no moonlight to interfere.