Venus is the planet that comes closest to the Earth and Neptune the farthest. When Venus passes directly between the Earth and sun, it’s just 23.6 million miles (38 million km) away. Standoffish Neptune only gets as close as 2.7 billion miles, more than 100 times farther away. And yet the two planets will appear very close together in the sky this week. Almost touching. When you see them in binoculars, use your imagination to picture the gulf that separates them.
Last night the two planets were just 2° (four full moon diameters) and fit comfortably in the same binocular field of view. Tonight (Jan. 26) 1° will separate them, and on Monday, Jan. 27 just 0.16° or a third of a full moon. That’s so close that the glare from Venus may drown out poor Neptune, at least in binoculars. Telescopes will have no problem. The two will be closest at 0.06° around 2 o’clock in the afternoon Central Time. Unfortunately, they’ll be invisible in daylight in the U.S., but observers in Western Africa and Western Europe can catch the sight.
Finding Venus is one of the easiest things on Earth to do right now. Face southwest from 30 to 90 minutes after sunset, and you’ll see a singularly bright object. Yep, that’s Venus! Neptune glimmers at magnitude 8, almost 60,000 times fainter. But don’t let that number scare you. The remote planet is visible in a pair of 50mm or larger binoculars, spotting scopes and any small telescope even from moderately light-polluted suburban areas. And you’ll have Venus nearby to guide you to it.
While Venus is visible even before sunset (if you know just where to look), you’ll need to wait until the sky is dark before seeking Neptune. I recommend starting about 90 minutes after sundown. Aim your binoculars at the planet and use the map to pinpoint the distant planet. Venus is moving up and away from the western horizon from our perspective as it orbits the sun. Meanwhile, Earth’s orbital motion causes Neptune (and all the other stars in the west) to sink closer to the western horizon each night. Moving in opposite directions the two planets come close to a head-on “collision” Monday!
That’s not all. A skinny lunar crescent hangs well below Venus and above Mercury on Sunday night, Jan. 26. Then on Monday, the moon shines just to the lower left of Venus. Whoa! What a show the next few nights. Clear skies!