Mercury in the Morning
Mercury is putting in its best showing for its current dawn appearance over the next few days. It's a fairly meager showing, but another bright planet helps point the way.
Look low in the east about 30 to 40 minutes before sunrise for Venus, the "morning star." Mercury is almost directly below Venus. It's only a few percent as bright, though, so you'll need to look carefully to see it.
Mercury is the closest planet to the Sun, so it never strays far from the Sun in our sky. That's why even the best appearances aren't usually that impressive.
Also because of its proximity to the Sun, Mercury flits back and forth between morning sky and evening sky every few weeks. This quick motion was responsible for the planet's name: Mercury was the Roman messenger god, who zipped across the sky with wings on his heels.
A spacecraft that arrived at Mercury in March carries the mythological theme a little farther. Since it's sending back messages about a planet named for the messenger god, the craft is called Messenger. It's the first spacecraft ever to orbit the little planet.
It's not the first spacecraft named in honor of the god, though. The name Mercury was chosen for the first craft to carry American astronauts into space. Program officials thought the god's rapid flight across the sky and his always-safe return to Earth were perfect fits. And in fact, the first astronaut took flight aboard Mercury 50 years ago. More about that tomorrow.
Script by Damond Benningfield, Copyright 2011
For more skywatching tips, astronomy news, and much more, read StarDate magazine.