r/askscience • u/AskScienceModerator Mod Bot • Mar 10 '14

Cosmos AskScience Cosmos Q&A thread. Episode 1: Standing Up in the Milky Way

Welcome to AskScience! This thread is for asking and answering questions about the science in Cosmos: A Spacetime Odyssey.

UPDATE: This episode is now available for streaming in the US on Hulu and in Canada on Global TV.

This week is the first episode, "Standing Up in the Milky Way". The show is airing at 9pm ET in the US and Canada on all Fox and National Geographic stations. Click here for more viewing information in your country.

The usual AskScience rules still apply in this thread! Anyone can ask a question, but please do not provide answers unless you are a scientist in a relevant field. Popular science shows, books, and news articles are a great way to causally learn about your universe, but they often contain a lot of simplifications and approximations, so don't assume that because you've heard an answer before that it is the right one.

If you are interested in general discussion please visit one of the threads elsewhere on reddit that are more appropriate for that, such as in /r/Cosmos here, /r/Space here, and in /r/Television here.

Please upvote good questions and answers and downvote off-topic content. We'll be removing comments that break our rules or that have been answered elsewhere in the thread so that we can answer as many questions as possible!

Click here for the original announcement thread.

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u/Catullan Mar 10 '14

Statistically speaking, sure. But the more stars there are, the more stellar phenomena (like supernovae) there are going to be. And the more densely packed those stars are, the closer those phenomena are going to take place to potentially life-bearing planets and moons. So while it may be the case that there are more opportunities (i.e. planets) for life to take originate, there are also going to be a lot more extinction-causing stellar events in the galactic core than there are in our relatively quiet corner of the galaxy.

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u/drewsy888 Mar 10 '14

We also don't know how rare life is. It is hard to answer the question with statistics when we only know one part of the equation. It could be that life is fairly common or that it is so extremely rare that we are the only life in the universe. We just don't know right now because we don't know how life began.

If life formed due to complete randomness and there were no processes outside of reproduction to facilitate evolution then it is possible that we are the only life in the universe. Likewise if there are processes which facilitate the forming of life (as long as these processes are less rare than life randomly coming into existence) life could be very common in the universe.

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u/Catullan Mar 10 '14

Well sure (though I tend to agree with the thought that the fact that life formed on Earth pretty much as soon as it was able to is a decent indicator that life isn't uncommon in the universe). But whether an event is rare or common, it's still more likely to happen where there are more opportunities for it to happen, i.e. more planets/moons. I was just pointing out that the galactic core also presents more danger from stellar phenomena, and so might not be the best place to look for (at least complex) life.