Moon, Venus, and Jupiter

• ‹ Previous program
• 334 of 1968
• Next program ›

With Thanksgiving behind us, the first Christmas lights are already blazing to life. But few of those displays will beat what Mother Nature is offering up the next couple of evenings: a conjunction of the three brightest objects in the night sky -- the Moon and the planets Venus and Jupiter. They're in the southwest at nightfall, and set in mid evening.

Both Venus and Jupiter reflect most of the sunlight that strikes them, because they're both topped by bright clouds. But several other factors make them look different in our night sky.

Right now, Venus looks about 10 times as bright as Jupiter. That's because it's much closer to both Earth and the Sun than Jupiter is. Every square foot of Venus gets about 50 times more sunlight than a square foot of Jupiter does, and more of that light bounces to the nearby Earth.

But Jupiter is far bigger than Venus, so it has a lot more square feet. So if you lined up the two planets side by side, there'd be no contest -- Jupiter would shine about a hundred times brighter.

Look for these brilliant planets in the southwest beginning not long after sunset. Brighter Venus is a little to the upper left of the Moon, with Jupiter quite close to the upper right of Venus. All three of them drop from sight by around 9 o'clock. And they'll team up again tomorrow evening, with the Moon above the brilliant planets.

We'll have more about this lineup tomorrow.

Script by Damond Benningfield, Copyright 2008

For more skywatching tips, astronomy news, and much more, read StarDate magazine.