Welcome to Astronomy & Telescope Astronomy



· Home
· AvantGo
· Content
· Downloads
· Encyclopedia
· Feedback
· Forums
· Journal
· Members List
· Private Messages
· Recommend Us
· Reviews
· Search
· Statistics
· Stories Archive
· Submit News
· Surveys
· Top 10
· Topics
· Web Links
· Your Account

  Who's Online

There are currently, 9 guest(s) and 0 member(s) that are online.

You are Anonymous user. You can register for free by clicking here




Select Interface Language:


  Random Headlines

[ Voyager ]

·Astronomy: Voyager - SOLAR PROBES
·Astronomy: Voyager - GALILEO
·Astronomy: Voyager - COMET MISSIONS
·Astronomy: Voyager - VOYAGER AND BEYOND

  Moon History: Astronomy: Moon History - IMPACTS, CRATERS, AND BASINS
Posted on Saturday, December 04 @ 16:12:56 CST by astronomy
  Moon History


A telescope shows an amazing array of lunar features. Most are the result of impacts by meteorites, asteroids, and comets. When a piece ot rock, ice, or anything hits the Moon at several miles per second, it blows up in a cloud ot vapor, blasting a scar on the Moon's surface.

Small impacts make tidy, bowl-shaped craters, such as Aristarchus, which is only 25 miles (40 km) across. These small craters are surrounded by aprons of ejected rock fragments, seen as bright areas around the younger craters.

Bigger impacts make larger craters with a more complex structure. A good example is Copernicus, 57 miles (92 km) across, with central peaks formed from pieces of deep lunar crust thrust upward by the shock of the impact. Landslides have terraced the inside of the crater's walls, and hardened pools of impact-melted rock are littered across its floor.

Craters that are larger still tend to resemble walled plains. They have flat or convex floors and their central peaks may form concentric rings. These big craters rarely have rays, however, because rays disappear in about a billion years through the action of tiny meteorites striking the surface—and all of the largest craters are older than that.

The biggest craters are called basins. Filled by Mare Imbrium, the Imbrium basin spans 720 miles (1,160 km)—about the size of Texas—and was created by a small asteroid about 3.9 billion years ago. The Apennine Mountains form the southeastern part of the Imbrium basin's rim.




Don't have an account yet? You can create one. As a registered user you have some advantages like theme manager, comments configuration and post comments with your name.

  Related Links

· More about Moon History
· News by astronomy

Most read story about Moon History:
Astronomy: Moon History - LIQUID ROCK


  Article Rating

Average Score: 0
Votes: 0

Please take a second and vote for this article:

Very Good



 Printer Friendly Printer Friendly

 Send to a Friend Send to a Friend


Associated Topics

Moon History

"Login" | Login/Create an Account | 0 comments
The comments are owned by the poster. We aren't responsible for their content.

No Comments Allowed for Anonymous, please register

  Astronomy & Telescope Astronomy

All logos and trademarks in this site are property of their respective owner. The comments are property of their posters, all the rest © 2004 by Astronomy & Telescope Astronomy
You can syndicate our news using the file backend.php or ultramode.txt