Page 63 - All About Space 68 - 2017 UK

Life but not as we know it it
Life but not as we know

EUROPA

Underground

oceans teaming

with life

Europa is one of Jupiter’s moons, but sits 241,000
kilometres (150,000 miles) further out in its orbit around
the gas giant than sister moon Io. Europa has become an
exhilarating target for astrobiologists, as in recent years a
lot of Europa’s interior has become apparent. This interior
appears to have an ocean just below the surface, which is
what is replenishing the face of the icy moon, giving it the
appearance of a young stellar body.
What makes this ocean so tantalising is that it could
be the most habitable region in the Solar System, bar “Perhaps Europa
Earth. Similar to its celestial sister Io, Europa endures tidal
heating because of the powerful gravity of Jupiter. has a better chance
“Perhaps Europa has a better chance of life surviving
today than Mars does, because Europa we think still of life surviving
provides a warm, wet, habitable environment. Whereas
Mars is now very cold, dry and hostile on its surface,” says today than Mars”
Dartnell. “Europa might be habitable for marine bacteria,
like we have on Earth, and potentially things that are Lewis Dartnell
more complicated than bacteria. But we don’t know as we
haven’t explored there yet.”
If there was a complex life to exist in this environment,
one particular creature springs to mind, and it’s called
the tardigrade. Also known as the water bear, it’s a
microscopic animal that resides in a variety of conditions,
but is indigenous to water regions. Tardigrades are not
considered an extremophile, but can certainly survive
a variety of extreme conditions, including temperatures
ranging from 1 Kelvin (-270 degrees Celsius) to 420 Kelvin
(145 degrees Celsius), heavy radiation and even a wide
range of pressure. In 2011, the tardigrade even became the
first animal to survive in space, conquering the freezing
temperatures, radiation-filled and oxygen-deprived
vacuum of space.

© Tobias Roetsch

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