Tonight Is the Best Time of the Year to See Jupiter and Its Many Moons

A spectacular celestial event is set to arrive just in time to beat stargazers’ Monday blues. As NASA notes in a blog post detailing its June skywatching tips, Jupiter will align with Earth and the sun tonight, standing alongside our planet and the fiery star in a perfect straight line.

This phenomenon, known as opposition, occurs just once every 13 months and finds the gas giant reaching its closest distance to Earth. Most significantly for space enthusiasts, opposition marks the year’s most optimal Jupiter viewing conditions, enabling binocular-equipped watchers to easily spot the planet and perhaps even a few of its 79 moons.

According to Vox’s Brian Resnick, Jupiter will grace the southeastern sky at dusk and remain visible until setting in the west at dawn. Those with binoculars should be able to see both the enormous planet, officially the largest in our solar system, and its four brightest moons—Io, Europa, Callisto and Ganymede. If you own a telescope, you may also be able to make out individual cloud bands and Jupiter’s characteristic Great Red Spot.

To locate Jupiter, simply look to the southeast and find the brightest object in the sky, excluding Venus and the moon, as Inverse’s Scott Snowden points out. Although the precise moment of opposition will take place at 6 p.m. Eastern time, Sky & Telescope’s Bob King writes that the planet will reach ideal viewing height around 11:30 p.m. and will remain visible through sunrise, or roughly 7 a.m.

Speaking with CNN’s Amy Woodyatt and Madeline Holcombe, Robert Massey, deputy executive director of Britain’s Royal Astronomical Society, offers several tips for stargazers: “Unlike stars, it won't twinkle,” he says. “Even when it's low down, it will look pretty steady, and that will make it stand out. You'll need a good clear southern horizon to see it.”

Resnick suggests using a smartphone app like Sky Guide to track Jupiter’s progress across the night sky and pinpoint the best time to take out your binoculars. EarthSky and In-the-Sky.org also have comprehensive guides to the annual event.

If you don’t have time to search the skies tonight, don’t worry too much. As NASA explains, “Although opposition takes place on a specific date, the entire month or so around opposition is an equally good time to observe the planet.” (Considering the fact that widespread clouds and rain are currently poised to obscure stargazing opportunities across the eastern United States, you may actually enjoy a better view on a later, clearer night.) And even if you miss this year’s Jupiter opposition, you’ll have another opportunity 13 months from now in July 2020.

Between June 14 and 19, Jupiter will be at the center of another celestial event. During this period, the moon will form a slightly shifting lineup with Jupiter and Saturn, changing in tandem with its orbit around Earth. Look closely, the space agency advises, and you will see that the moon doesn’t trace the same path followed by Earth and other planets orbiting the sun. Instead, the moon’s orbit is slightly tilted, making the astronomical body align with the sun and Earth—creating conditions for a lunar or solar eclipse—just a few times a year rather than on a regular basis.

Meilan Solly | | READ MORE

Meilan Solly is Smithsonian magazine's associate digital editor, history.