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[Music] [Title:
RE-ANALYZING OLD DATA

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REVEALS EVIDENCE AT EUROPA]

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[Robert Poppalardo] We
didn't know 'til today

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that there's evidence
from years ago

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that there's
something there.

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Europa is one of the
most fascinating

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bodies in the
solar system.

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We think beneath its icy
surface is a global ocean

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twice the volume of all of
Earth's oceans combined.

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In the late 1990s, the
Galileo spacecraft

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explored the Jupiter system.

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It made about a dozen
flybys of Europa.

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It took observations
from its cameras

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and from its magnetometer.

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[Margaret Kivelson] By
discovering that there was

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an induced magnetic
field at Europa,

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we were led to the
conclusion that there must be

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an ocean just beneath the icy
surface of the moon.

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But there were some strange
signatures in the magnetic field

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that we had never really
been able to account for.

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[Poppalardo] Images of
Europa from the

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Hubble space telescope have
hinted at gases that

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might have come from plumes
erupting at Europa.

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[Kivelson] The Hubble images
had given an estimate

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of the height and width
and I knew how fast

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Galileo was moving
relative to Europa.

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There are better
tools now...

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better computational
techniques...

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better computing...
that we can go back

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and look at that
old dataset anew.

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So, my colleague Xianzhe Jia
set up a calculation to see

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what would happen in the
environment of Europa

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if there were
such a plume.

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And when he ran this
simulation, it agreed

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just beautifully with the data
that we had collected.

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Reanalysis of the Galileo
magnetometer data suggests

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that the Galileo spacecraft,
on its closest flyby of Europa,

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flew through a plume.

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The Europa Clipper mission is
going to explore Europa

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to investigate
its habitability.

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If we find active plumes, then
we can sail on through them

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and sniff and taste that stuff
that's in the plume.

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We can analyze the particles
and the gases to get at the