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Do Aliens Exist?

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We Asked a NASA Scientist.

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That's a really interesting question and one\h
that we have been trying to understand and

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explore and and figure out for a really long\h
time. We have not yet discovered life on any

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other planet. We haven't seen any scientifically\h
supported evidence for extraterrestrial life.

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But if we think about life on this planet, beyond\h
the big things — the elephants, the whales, redwoods,

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and focus on the tiny things, nearly everywhere on\h
Earth that we've looked, we've found microbial life.

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And our definition of habitable continues to\h
expand. Off the Earth we've only begun to look.

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NASA has sent five rovers and four landers to the\h
surface of Mars. In addition to that, our orbiters

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have been outfitted with some amazing cameras to\h
take pictures of the whole surface of the planet.

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And we've only explored a tiny fraction of Mars.\h
And that's only one of the promising bodies to

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look for life in our solar system. There are\h
icy moons in the outer solar system like

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Enceladus and Europa that look like they may\h
have subsurface oceans that could be habitable.

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And then that's just what's in our solar system.\h
The more exoplanets we find around other stars,

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the more we learn about how many different\h
environments could exist for life. So we can't yet

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say for sure whether or not aliens exist. 
But\hto quote Carl Sagan: The universe is a pretty

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big place. If it's just us, it seems like an\h
awful waste of space. So we will keep looking.