Beautiful Pairings

The solar system serves up a couple of beautiful pairings just after sunset this evening. One of them disappears with the twilight. But the other will be on magnificent display all night long.

The planets Mercury and Mars are quite low in the west-northwest a half hour after the Sun drops from view. Mercury is bright, so it’s a fairly easy target, although you need a clear horizon to spot it. Mars is only a few percent as bright as Mercury. But it’s only a degree or so to the upper left of Mercury, which can help you pick it out.

Mercury and Mars will vanish by about the time the sky gets fully dark, as they follow the Sun below the horizon.

As that happens, though, the other pair will be climbing skyward in the southeast: the full Moon and the planet Jupiter, which looks like a brilliant star to the upper right of the Moon.

Both worlds align opposite the Sun right now, so they’re in view all night. Their path stays quite low in the south, though, so they won’t climb very high into the sky.

That path is known as the ecliptic. Technically, it’s the Sun’s path. But the Moon and planets stay quite close to the ecliptic, so they outline the Sun’s annual migration across the sky. Mercury and Mars, for example, are near the western edge of the constellation Gemini — just where the Sun will stand in a few weeks. And the Moon and Jupiter are in southern Ophiuchus — the Sun’s home in the first half of December.

Script by Damond Benningfield