Basic guidelines: You read an article on astronomy, exobiology, or cosmology in a lay science site or a lay science magazine that puzzles you? Ask away! Please provide a link if at all possible. Notable exceptions: You read something about Planet Niburu, Planet X, or the year 2012? Please don't ask. That stuff is not even pseudoscience. You want to know more about NASA or ESA or one of the other space agencies? Ask away. Notable exception: We really did send people to the moon 40 years ago, no ifs ands or buts. You found some ultra-cool astronomy photo you would like to share? Post it. A picture is worth a thousand words. Notable exception: Some pictures are worth a million words, easily. Please do not post *huge* images using the [ img ] tags capability. Instead, make a compressed version of the image. Post the compressed image as an [ img ] tag and post a link to the full-sized image as a [ url ] tag. How to make a compressed image? One way to do that is to go to http://www.TinyPic.com, paste in the URL to the oversized image, select "Message Board (640x480)" from the resize menu, and click the Upload button. Presto chango, you have a compressed version of the big picture suitable for embedding. You want to discuss theoretical aspects of astronomy, exobiology, or cosmology? Discuss away! Several members at sciforums.com are knowledgeable in various aspects of the underlying theories. Notable exception: You *know* with a certainty that basic aspects of special relativity, general relativity, or the age of the universe are wrong? The answer to the ultimate question is not 42? You have your own pet theory of the origin of the universe? The appropriate venue for such discussions is the pseudoscience sub forum, not here. In addition to the above, Stay on topic. Off-topic posts will be moved or removed. Try to make your writing clear, concise, and readable. I'm not expecting perfect composition, but please do try. Avoid overly contrived writing styles such as waxing poetic, writing in multiple colors, and writing in multiple fonts. Doing so tends to detract from rather than add to what you wrote. Give proper attribution when you copy text from some other source. NO PLAGIARISM. Give a url reference if possible. Do not cut-and-paste the whole 10 page article. Much better is to give a short synopsis and a reference for further reading.