On June 22 to 24, 2018, look at the bright waxing gibbous moon as soon as darkness falls. That nearby brilliant “star” nearby is no star at all. It’s the giant planet Jupiter, fifth planet outward from the sun. As the moon makes its monthly rounds in front of the constellations of the zodiac, it swings in the vicinity of Jupiter for a few days each month. And these next few days present a great time to use the moon to find Jupiter.
Now look again at the chart at the top of this post. See the star Antares? By June 24 and 25, the moon will have moved closer to Antares, which is a bright red star, the Heart of the Scorpion in the constellation Scorpius.
As seen from the Americas, the moon pairs up most closely with Jupiter on June 23. As seen from around the globe, the moon swings to the north of Jupiter on June 23. Then, by the evening of June 24, Jupiter can be found from all parts of Earth to the west of the moon. On June 24, the moon will be shining near the head of Scorpius. If your sky is dark enough, you might be able to spot three stars – sometimes called the Crown of the Scorpion – in the moon’s glare. If you can’t see them, use the bright star Antares to guide you to the Crown of the Scorpion when the moon drops out the evening sky in July.
Next … there’s another star you can learn to identify now, with Jupiter’s help.
It’s shown in the next image down.
Jupiter now shines in front of the constellation Libra the Scales, and will continue to light up this constellation for many months to come. Jupiter and Libra’s alpha star, Zubenelgenubi, are now so close together on the sky’s dome that both the planet and the star easily fit inside the same binocular field of view.
Most all the time, Jupiter ranks as the fourth-brightest celestial body after the sun, moon and Venus. But Mars is brightening as we speak and will soon supplant Jupiter as the fourth-brightest celestial body, if it hasn’t already. If you wish to compare Mars and Jupiter later tonight, look for Mars to rise in the east after Venus sets in the west. Or, if that’s too late for you, wake up before daybreak to see the planets Mars and Jupiter in the same sky.
Saturn is up, there, too, by the way.
The moon will be moving past both Saturn and then Mars before this month’s end:
By the way, when we say the moon is near a planet, like Jupiter, we of course mean these two worlds are close together on the sky’s dome. The moon and Jupiter are not close together in space. The moon, our closest neighbor world, lies some 242,000 miles (390,000 km) distant from Earth. Jupiter orbits our sun much farther away. It’s nearly 1,800 times the moon’s distance from us.
Astronomers often give the distances to solar system planets, such as Jupiter, in astronomical units (AU). The astronomical unit is based on the Earth’s distance from the sun, a measure of about 93 million miles or 150 million km. At present, Jupiter resides some 4.66 AU from Earth and 5.4 AU from the sun.
Want to know more precisely the distance of Jupiter (or other solar system planets) for right now or some chosen date? Heavens-Above.com is a good source for that info.
Or … want to know which constellation of the zodiac the moon is traveling in front of right now (or some chosen date)? Then check out this page at Heavens Above..
On June 22, the moon is only about 0.0026 AU from Earth. Generally, astronomers give the moon’s distance in miles or kilometers, not AU. Sometimes, they give the moon’s distance in Earth radii (ER).
Radii is plural for radius, and one Earth radius equals 3.960 miles or 6,370 km. The June 22 moon is about 60 ER away. You can more precisely find out the moon’s present distance in Earth radii (ER) by visiting Fourmilab’s site, or at Time.unitarium.com if you want to know the moon’s distance in miles, kilometers or AU.
Click here for a recommended almanac for the setting and rising times of the planets in your sky.
Bottom line: Use the moon to locate the giant planet Jupiter on the nights of June 22, 23 and 24, 2018.
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.