The two brightest planets are gliding closer in the early evening sky and their celestial dance culminates with an ultra-close pairing on June 30th.
According to Sky and Telescope, the two brightest planets, Venus and Jupiter, have been drawing closer in the west in the evening twilight. At the beginning of June, the two planets were 20 degrees apart in the sky, about twice the width of a fist held at arm's length. Week by week, Jupiter and the stars behind it have gradually slipped lower in the evening twilight. But Venus, due to its rapid orbital motion around the Sun, has stayed high up.
The resulting slow-motion convergence is setting the stage for a dramatic sky sight. The warm-up act came on June 19 and 20, when the planetary duo was joined by a thin and lovely crescent Moon. Farther to their upper left, and fainter, was Regulus, the alpha star of Leo.
But now the spectacle is taking an even more dramatic turn—one you just cannot miss. For eight nights beginning June 27, these two bright planets will be within 2° of each other—close enough to cover both with the thumb of an outstretched hand. In the midst of that weeklong run, on June 30, Venus and Jupiter will appear so close—just 1/3° apart—that they'll look like a tight, brilliant double star in the evening sky.
Such conjunctions, or close pairings, of these two planets are not particularly rare. The orbit of Venus is tipped just 3.4° with respect to Earth's, Jupiter even less at 1.3°. So these close conjunctions are destined to occur.
On June 30, both planets will crowd into the same telescopic field of view, Venus appearing as a fat crescent and round Jupiter accompanied by its four largest moons, a telescope or binoculars is sure to come in handy.
