We’ve watched Venus and Jupiter edge closer and closer together all month as they cavorted with a crescent moon, and now the two planets are poised to merge into a single brilliant beacon.
For just one night, on Tuesday June 30, the sky’s second- and third-brightest lights (surpassed only by the moon, which becomes full on July 1) will join together to make for a stunning twilight into evening. They will be hard to miss as the sun sets, emerging as the sky deepens from magenta to mauve to periwinkle.
“Look to the western sky less than an hour after sunset, and you won’t be able to miss two bright points of light more than a fourth of the way above the horizon,” says Astronomy.com. “That more brilliant one is Venus, and it’s currently having its best showing for northern observers of 2015 as it shines brightest and appears highest in the evening sky. And right now, it's joined by Jupiter for the first and closest conjunction in a rare set of three.”
We have watched the two flirt since the start of June, and the gap has been visibly narrowing in particular over the past few days. On June 30 they will appear less than a chopstick-width apart, as Sky and Telescope says.
Of course, Jupiter is actually 12 times the diameter of Venus, as Astronomy.com points out, but it’s also 12 times farther from Earth than is our so-called sister planet closer to the sun.
“In reality, they're very far apart in space,” notes Sky and Telescope. “Venus is currently 48 million miles from Earth; Jupiter is a dozen times farther away at 565 million miles, on the other side of the solar system.”
Nevertheless, “They'll remain strikingly close together for days to come,” says Sky and Telescope. The two last rendezvoused in August 2014, in a morning tryst that had them a tad closer together but lower to the horizon.
This year’s evening show continues on Wednesday July 1, when the “dazzling planets stand side by side in the west, still with just a full moon’s width between them,” Astronomy.com says. Watching over them will be the full moon, the first of two coming in July. “Only the full moon itself—climbing higher in the southeastern sky this evening—appears brighter.”
That moon becomes full at precisely 10:20 p.m. EDT. As for Venus and Jupiter, we will not see the likes of this for more than a year, says Earthsky.org.
“Venus and Jupiter both appear bright in Earth’s sky because the cloud cover on these worlds effectively reflects sunlight,” says Earthsky.org. “Although Jupiter is so much farther off than Venus, Jupiter’s sheer size guarantees the king planet’s brilliance. This is their closest pairing in the evening sky until August 27, 2016.”