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Astronomy Netcasts

by Kathleen Robertson, IfA Librarian

Netcasts are broadcasts distributed over the Internet. To oversimplify: podcasts are audio, like radio; vodcasts (short for "video podcasts") have video as well as sound. The term "netcast" was suggested by Leo Laporte, originator of This Week in Tech ( Although the name "podcast" is derived from the Apple iPod, it is not necessary to have an iPod to enjoy netcasts, just a computer and an Internet connection.

Some netcasts are streaming audio or video that you can listen to or watch only while you sit at your computer. Others are available for downloading. Once a netcast is downloaded, it can be played immediately or kept for later, and it can be transferred to an MP3 player such as an iPod for listening while on the go. You can download single episodes, or you can subscribe to a program and receive ongoing, automatic downloads.

If you are new to netcasts, a good place to start is Indiana University's Moments of Science (, which presents two-minute audio programs on a variety of science topics. "When the Sun Burps," "Moon Tan?" and "Hold on a Parsec" are among the astronomy episodes. For more of them, search for terms like "star" or "moon." You will need the program RealPlayer (see Technical Details below).

On Astronomy Cast (, bloggers Fraser Cain (Universe Today) and Pamela Gay (SIUE/Slacker Astronomy) discuss an astronomy topic each Monday. To stream a 30-minute episode, click on the right arrow next to the speaker icon. Show notes, with links to relevant sites, are provided for each episode. Opening the notes will stop the episode from streaming, so they should be opened in a second window. Archived episodes include tempting titles like "Pluto's Planetary Identity Crisis" and "Meteor Showers. Yes, the Sky Is Falling." If you like the offerings, you can subscribe to future episodes by clicking on the icons "RSS" or "iTunes" in the upper right corner (see Technical Details below).

Astronomy a Go Go! ( has rich multimedia offerings. Monthly sky tours describe celestial phenomenon in detail, with links to Northern and Southern Hemisphere sky maps. Midmonth episodes, called "Carpe Noctem--Seize the Night!" can cover any topic. One recent episode, "#36: Moons and Rings in Our Solar System," is a talk by Mark Showalter of the SETI Institute. You can download the PowerPoint presentation that accompanies the talk to watch while you listen. It is worth seeing just for the graphics.

Astronomy Media Player (AMP) ( tracks current astronomy multimedia offerings. It is an attempt to bring together a range of astronomy netcasts and to reformat them so that you need only one player. It is still experimental (beta) and may not work with all browsers. It does work with Firefox.

Kathleen Robertson

Technical Details: Your computer will need a sound card and one or more speakers (most new computers come with these), and you may need to download some software to hear or see these netcasts. QuickTime (the free version;, RealPlayer (; link to the free version is in the upper right corner), and iTunes ( are some of the more popular ones available for Windows and Macintosh computers.

To subscribe to netcasts, you'll need podcatcher software. Podcatchers work like blog feeds. Using an iTunes, RSS, or Atom feed, your computer will monitor the series you've subscribed to, and when a new episode is available, it will download it automatically. Juice (formerly iPodder) and iTunes are free and have both Macintosh and Windows versions. The Podcasting News website has a good list of both fee and free options, grouped by operating system.

Kathleen recommends these science sites that report on celestial stories:
Nature (magazine):
New Scientist (magazine):
Quirks & Quarks (CBC Radio):
The Smithsonian:
Science (magazine):
Science Friday (National Public Radio):
Scientific American (magazine):
For more podcasting information: