Tonight – June 22, 2018 – seek out the bright waxing gibbous moon as soon as darkness falls. That nearby brilliant “star” to the east of the moon on June 22 is actually no star at all. That’s the giant planet Jupiter, the 5th 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.
Want to know which constellation of the zodiac the moon is traveling in front of right now (or some chosen date)? Then click here.
Tomorrow night, on June 23, look for the moon to pair up most closely with Jupiter for the month. The moon swings to the north of Jupiter on June 23, and then on June 24 Jupiter is found to the west of the moon. (See sky chart.)
By the way, when we say the moon is near Jupiter, we really mean these two worlds are close together on the sky’s dome. The moon and Jupiter are actually not close together in space. The moon, our closest celestial neighbor, lies some 242,000 miles (390,000 km) distant from Earth. In contrast, Jupiter lodges way beyond the moon, at 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? Click here.
Tonight’s 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 = 3.960 miles or 6,370 km. Tonight’s moon is about 60 ER away. You can more precisely find out the moon’s present distance in Earth Radii (ER) by clicking here, or click here if you want to know the moon’s distance in miles, kilometers or AU.
Jupiter now shines in front of the constellation Libra the Scales, and will continue to light up this constellation for many months to come. In fact, Jupiter and Libra’s alpha star, Zubenelgenubi, are so close together on the sky’s dome that both Jupiter and Zubenelgenubi 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.
Click here for a recommended almanac for the setting and rising times of the planets in your sky.
The moon will be in the vicinity of Mars in late June and early July. In the meantime, use the moon to locate Jupiter on the nights of June 22, 23 and 24.