Moon and Planets

StarDate: July 10, 2009

You are missing some Flash content that should appear here! Perhaps your browser cannot display it, or maybe it did not initialize correctly.

audio/mpeg icon

The Moon and Jupiter put on a good show tonight. They rise in late evening and scoot over to the southwest by first light. Jupiter looks like a brilliant star, a little to the right of the Moon as they rise.

You can't see it with your eyes alone, but another prominent member of the solar system joins them -- the planet Neptune. It's just a whisker above Jupiter, but you need a telescope to pick it out. It looks like a tiny star.

Jupiter is the largest planet in the solar system, while Neptune ranks fourth. But there's not much resemblance between them.

Jupiter looks like a striped beachball. The stripes are in shades of tan, brown, and orange. Giant storms swirl through the stripes, including the biggest one of all, the Great Red Spot. The stripes are clouds that're stretched into globe-circling bands by Jupiter's fast rotation. They're colored by water, ammonia, sulfur, and other compounds dredged from deep below the cloudtops.

Neptune, on the other hand, is a rich shade of blue. To the eye alone, it shows fairly few features. Storms sometimes ripple across it, with either a dark swirl or bright streamers. Neptune's color comes from methane high in the atmosphere. It absorbs red wavelengths, allowing only the blue to shine through. The methane forms a haze that makes it tough to see clouds below.

Again, look for Jupiter -- and Neptune, if you have a telescope -- keeping close company with the Moon.

Script by Damond Benningfield, Copyright 2009

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

The one constant in the Universe: StarDate magazine


©2014 The University of Texas McDonald Observatory