We recently had a near brush with disaster as an asteroid passed 40,000 miles from earth. Well, it wasn't really that close to disaster, but considering the moon is only 240,000 miles from earth 40,000 miles is a little too close for comfort. What else is passing close to earth? On this week's SkyTalk find out about space dust and other space material the size of a grain of sand, or as big as a pebble.

Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

Get the mp3 »

Visit the Skytalk web page for more information.