Jupiter and Saturn are the planets to watch in July 2020. They are near one another on the sky’s dome, with Saturn following Jupiter westward across the sky from early evening until dawn. It’s a banner month for these gas giant worlds, as Jupiter and Saturn both come to opposition this month.
At and around opposition, Earth – in its yearly orbit – swings between these outer worlds and the sun. Thus we are closest to Jupiter and Saturn for the year this month. Jupiter and Saturn, in turn, shine at their brightest best and are out all night long.
Around the world, Jupiter and nearby Saturn rise during nightfall in early July, around sunset in mid-July, and before sundown by the month’s end. You can spot both Jupiter and Saturn easily in July 2020. Look first for brilliant Jupiter; Saturn is the bright object immediately to Jupiter’s east. Although Saturn is easily as bright as a 1st-magnitude star – as bright as the brightest stars in our sky – the ringed planet can’t compete with the the king planet Jupiter, which outshines Saturn by some 15 times.
After all, Jupiter ranks as the fourth brightest celestial object, after the sun, moon, and the planet Venus, respectively.
Jupiter and Saturn are having a great conjunction in 2020. Astronomers use the word conjunction to describe meetings of planets and other objects on our sky’s dome. They use the term great conjunction to describe a meeting of very bright Jupiter and golden Saturn. The last great Jupiter-Saturn conjunction was May 28, 2000. The next one will be December 21, 2020. But July 2020 – when both worlds reach opposition – is the time to start watching these worlds.
Watch for the moon in the vicinity of Jupiter and Saturn for several days, centered on or near July 5.
Mars is the first of the three bright morning planets to rise in July 2020. Mars comes up at late night, roughly around midnight. Then, a few to several hours later, Venus rises into the predawn sky; and by the second half of July 2020, Mercury will appear below Venus at morning dawn.
Sometime this month, Mars will rise before midnight, to sit low in the east at late evening. By August, look for Mars to be up by mid-to-late evening. Thus Mars is rising earlier, heading for its own opposition on October 13, 2020. At that wondrous time, Mars will actually supplant Jupiter as the sky’s fourth-brightest celestial body, after the sun, moon, and the planet Venus. That will be something to see!
In July 2020, you’ll find Mars heading toward that dramatic brightening around its October opposition. This month, Mars is respectably bright, easily as brilliant as a 1st-magnitude star, or one of the sky’s brightest stars. Earth is now rushing along in its smaller, faster orbit, gaining on Mars, the fourth planet outward from the sun. Throughout the next three months, watch for Mars to brighten dramatically as Earth closes in on Mars, passing between it and the sun in October.
At mid-northern latitudes, Mars rises around the midnight hour in early July, and roughly 10 p.m. (11 p.m. daylight saving time) by the month’s end. By midnight, we mean midway between sunset and sunrise.
At temperate latitudes in the Southern Hemisphere, Mars comes up at or near the midnight hour in early July, and about an hour earlier by the month’s end.
Let the waning moon help guide your eye to Mars on the mornings of July 11 and 12.
Venus – the brightest planet – rushed between the Earth and sun (inferior conjunction) on June 3, 2020. At that point, it transitioned out of the evening sky and into the morning sky. We first saw Venus reappear in the east at dawn around mid-June. Throughout July, this blazing world will climb progressively higher into the eastern predawn sky.
At mid-northern latitudes, Venus rises about 2 hours before the sun in early July, increasing to about 3 hours by the month’s end.
At and near the equator, Venus rises about 2 1/3 hours before the sun in early July, increasing to over 3 hours near the month’s end.
At temperate latitudes in the Southern Hemisphere, Venus rises about 2 2/3 hours before the sun in early July, increasing to over 3 hours by the month’s end.
Throughout July, Venus in its faster orbit around the sun will be going farther and farther away from Earth. As viewed through the telescope, Venus’ waxing crescent phase will widen, yet its overall disk size will shrink. Venus’ disk is 19% illuminated in early July, and about 42% illuminated by the month’s end; Venus’ angular diameter, on the other hand, will shrink to 2/3 the size by the month’s end.
Look for Venus to beam at its brightest in the morning sky on or around July 10, 2020, when Venus displays its greatest illuminated extent on the sky’s dome. Venus always beams at its brightest best when its disk is about 1/4 illuminated by sunshine. In fact, if you’re up before dawn, note that Venus at its brightest closely couples up with Aldebaran, the brightest star in the constellation Taurus the Bull.
Watch for the waning crescent moon in the vicinity of Venus for several days, centered on or near July 17.
Mercury transitions out of the evening sky and into the morning sky on July 1, and then reaches its greatest elongation in the morning sky on July 22, 2020. We expect Mercury to become visible in the eastern dawn sky around mid-month. Have binoculars handy, however, for Mercury has to compete with the glow of morning twilight. Given an unobstructed horizon in the direction of sunrise, you have a reasonably good chance of catching Mercury in the second half of July, as this world brightens throughout the month.
For several mornings, starting on or around July 16, let the waning crescent moon and the brilliant planet Venus guide you to Mercury’s place near the horizon.
Mercury reaches its greatest elongation on July 22, 2020, at which time Mercury will be 20 degrees west of the sun. After that date, Mercury will slowly fall sunward day by day.
40 degrees north latitude:
July 15: Mercury rises 66 minutes (1 1/10 hours) before the sun
July 22: Mercury rises 90 minutes (1 1/2 hours) before the sun
August 1: Mercury rises 80 minutes (1 1/3 hours) before the sun
Equator (0 degrees latitude)
July 15: Mercury rises 75 minutes (1 1/4 hours) before sunrise
July 22: Mercury rises 84 minutes (1 2/5 hours) before sunrise
August 1: Mercury rises 66 minutes (1 1/10 hours) before sunrise
35 degrees south latitude
July 15: Mercury rises 80 minutes (1 1/3 hours) before sunrise
July 22: Mercury rises 80 minutes (1 1/3 hours) before sunrise
August 1: Mercury rises 45 minutes (3/4 hour) before sunrise
What do we mean by bright planet? By bright planet, we mean any solar system planet that is easily visible without an optical aid and that has been watched by our ancestors since time immemorial. In their outward order from the sun, the five bright planets are Mercury, Venus, Mars, Jupiter and Saturn. These planets actually do appear bright in our sky. They are typically as bright as – or brighter than – the brightest stars. Plus, these relatively nearby worlds tend to shine with a steadier light than the distant, twinkling stars. You can spot them, and come to know them as faithful friends, if you try.
Bottom line: July 2020 presents all 5 bright solar system planets. Catch Jupiter and Saturn at early evening and throughout the night, Mars between midnight and dawn, Venus in the predawn/dawn sky, and Mercury below Venus at dawn in the second half of July.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.