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the search for life beyond Earth begins

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with understanding life on our home

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planet and that story the story of life

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on Earth

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may have begun in our oceans and that's

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because of course if we've learned

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anything about life on Earth it's at

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where you find the liquid water you

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so what if I told you that there is an

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ocean out there beyond earth an ocean in

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our solar system that has been in

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existence for billions of years it's an

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ocean that is perhaps ten times as deep

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as Earth's ocean it's an ocean that is

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global and may contain two to three

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times the volume of all the liquid water

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on the earth it's an ocean that exists

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beneath the icy shell of Jupiter's moon

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Europa so how do we think we know that

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Europa's ocean exists well it's a

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combination of using telescopes on the

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ground and having spacecraft that have

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flown by Europa and collected data about

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the surface about the interior structure

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and about the magnetic field around

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Europa and the combination of those data

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sets leads us to a high degree of

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confidence that this global liquid water

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h2o ocean is there today and it's been

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there for much of the history of the

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we used to think that in order for a

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world to be habitable you had to be just

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the right distance from the Sun or

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whatever your star was such that you

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could have a liquid water ocean on the

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surface now along with liquid water life

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as we know it needs two other key stones

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the first is the building blocks for

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life the stuff you find in rocks and the

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second is some form of energy to help

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power life and here's where Europa is a

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real gamechanger it is far far out from

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the Sun and yet it's got this liquid

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water ocean and the reason that Europa

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has liquid water is because it's

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orbiting Jupiter and the tidal tugging

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pull causes your OPA to flex up and down

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and all that tidal energy turns into

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mechanical energy which turns into

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friction and heat that helps maintain

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this liquid water ocean beneath

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nicshelle along with helping maintain

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liquid water we think that tidal energy

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may also allow that ocean to interact

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with rocks on Europa seafloor and it may

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even give rise to things like

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hydrothermal vents which could help

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provide not just the building blocks for

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the question of whether or not life

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exists beyond the question of whether or

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not biology works beyond our home planet

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is one of humanity's oldest and yet

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unanswered questions and for the first

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time in the history of humanity we have

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the tools and technology and capability

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to potentially answer this question and