Want your own question answered? Put it in a video and post it here on YouTube. We'll have NOVA scienceNOW's experts answer selected submissions. This is a rare opportunity, so come up with questions, make a video, and send it in.

Video questions will be selected and posted on the Cosmic Perspective page on the NOVA scienceNOW website and then be answered by our experts throughout the season of NOVA scienceNOW, via text on our website, with the last question being answered the day after the final broadcast, September 20, 2009. http://www.pbs.org/wgbh/nova/sciencenow/cosmic/

Submission Guidelines

1. Submission deadline is September 15 , 2009.

2. Make a submission asking a question using video via YouTube. Upload your creation as a response to our Ask The Astrophysicist video promo on the NOVAonline YouTube Channel (Tag your submission & be sure to include the tag "ask_ astrophysicist")

3. Please keep your submission to three minutes or less.

NOVA scienceNOW does not claim ownership of the submitted materials you post to YouTube (collectively, "Submissions"). In addition to the YouTube Terms of Service, by posting, uploading, or submitting your video you are granting NOVA scienceNOW permission to post your Submission on the NOVA scienceNOW website in connection with the Ask The Astrophysicist.

No compensation will be paid with respect to the posting of your Submission on the NOVA scienceNOW website. NOVA scienceNOW is under no obligation to post or use any Submission you may provide and may remove any Submission at any time in NOVA scienceNOW's sole discretion.

By posting your Submission to YouTube in response to our Ask the Astrophysicist video promo, you represent and warrant that you own or otherwise control all of the rights necessary for you to post, upload, input or submit your Submission, including, without limitation, obtaining all necessary clearances for persons, places and materials contained in your Submission.

NOVA scienceNOW is a trademark of the WGBH Educational Foundation.

NOVA scienceNOW is produced for WGBH/Boston by NOVA.