Tonight Jupiter and Venus will merge into a dazzling “super-star” in the Western horizon by the end of June, NASA says. The conjunction of the two planets has been building during the month of June and will culminate in a spectacular display on June 30. “Every night in June, the separation between Venus and Jupiter will visibly shrink,” says NASA.
A conjunction is when two or more objects appear very close together on the sky. On the evening of June 30, Venus and Jupiter will appear in the sky just a third of a degree apart. “That’s less than the diameter of a full Moon. You’ll be able to hide the pair not just behind the palm of your outstretched hand, but behind your little pinky finger,” NASA enthuses. Sky & Telescope suggests that a similar rare conjunction of Venus and Jupiter may have been what’s been called the “Star of Bethlehem” in 3-2 BC. There has not been a brighter, closer planetary conjunction in the 2,000 years since.
While the conjunction is certainly visible with the naked eye, Sky and Telescope says viewing it with a telescope or binoculars will offer a different perspective: “Both planets will crowd into same telescopic field of view, Venus appearing as a fat crescent and round Jupiter accompanied by its four large moons. The two planets will appear nearly as the same size, but Jupiter, though much larger in reality, is much farther away…. Their globes will contrast dramatically in brightness, with Venus’s crescent appearing dazzling white compared to Jupiter’s duller, striped cloud deck.”
Pat Hartigan, an astronomer at Rice University, says the conjunction on June 30 is the best one we will have for over a decade, rivaled only by one on March 1, 2023, which will not be not quite as close.
So where and when should we look for it? Look to the west-northwest as soon as it gets dark, says Dr. Hartigan. “After about two hours for most latitudes the objects will become difficult to observe as they begin to set. They are bright. You might mistake them for airplanes.”
Is this a significant astronomical event? Not really. “These planetary groupings in the sky have no effect on Earth or human affairs – except for one,” says Alan MacRobert at Sky & Telescope. “They can lift our attention away from our own little world into the enormous things beyond. That’s what amateur astronomers do all the time.”