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JACKIE FAHERTY (Senior Scientist, Division of Physical Sciences, American Museum of Natural History): Is there life in the universe?

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FAHERTY: There are two ways to answer that question. One is via science. You try and quantify anything that goes into that question. The other is your gut. We'll get to that one at the end.

For the scientific way we can really thank an astronomer named Frank Drake, who came up with an equation, in the 1960s, that attempts to give a quantifiable approach to answer this question. And Drake's equation has a number of pieces that go into it, to give you a number at the end of how many planets might you expect intelligent life to exist on.

One piece that's pretty basic is how many stars are there in the galaxy? How many of those stars have planets around them? How many of those planets are in the habitable zone of their star? And then it gets a little bit more complicated, into things that we're not quite sure how to answer. How often does microbial life sprout up on a planet? And then how often does intelligent life emerge from that?

You can get an answer that's as small as just the Earth, or as large as hundreds of thousands if not millions of planets in our own galaxy that might have intelligent life on them. And that kind of range from basically nothing to everything means we don’t have enough information to confidently say one way or another.

Drake's Equation is definitely one way that you can go about trying to get to the answer, but I just don't think that you're going to have a pen and paper answer to "Is there life in the universe?" I actually think it's going to come about because of a discovery. That's why I turn to my gut for the answer to this question. I see life everywhere on this planet. I feel strongly that the oceans of Enceladus and Europa are going to end up having microbial life, or some sort of life in them, and so my natural answer is “Yes, there is life out there in the universe.” 

But if a discovery doesn't happen in my lifetime, I'm not going to count it as “no”. Because the lack of a discovery doesn't mean that it doesn't exist. Astronomers certainly won't stop looking - this will always be a question that we seek to have an answer to.

Thanks for watching everyone. Be sure to subscribe to the AMNH channel for more videos like this. And you can click the link above my head so that you can get the next dino video that we’ve got lined up for you.

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