Europa’s Watery under World
Europa, one of Jupiter’s 63 known moons, looks bright and icy on the surface.
But appearances can be deceiving: Miles within its cracked, frigid shell, Europa
probably hides giant pools of liquid water. Where scientists find liquid water,
they hope to find life as well. Since we can’t go diving into
Europa’s depths just yet, scientists instead have to investigate the moon’s
surface for clues to what lies beneath. In a new study, scientists investigated
one group of strange ice patterns on Europa and concluded that the formations
mark the top of an underground pool that holds as much water as the U. S. Great
Lakes. Pictures of Europa, which is slightly smaller than
Earth’s moon, clearly show a tangled, icy mishmash of lines and cracks known as
"chaos terrains." These chaotic places cover more than half of Europa. For more
than 10 years, scientists have wondered what causes the formations. The new
study suggests that they arise from the mixing of vast underground stores of
liquid water with icy material near the surface. For scientists
who suspect that Europa also may be hiding life beneath its icy surface, the
news about the new lake is exciting. "It would be great if
these lakes harbored life, " Britney Schmidt, a planetary scientist who worked
on the study, told Science News. "But even if they didn’t, they say that Europa
is doing something interesting and active right now. " Schmidt,
a scientist at the University of Texas at Austin, and her colleagues wanted to
know how chaos terrains form. Since they couldn’t rocket to Europa to see for
themselves, they searched for similar formations here on Earth. They studied
collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those
features on Earth formed when liquid water mixed with ice. The scientists now
suspect something similar might be happening on Europa: that as water and ice of
different temperatures mingle and shift, the surface fractures. This would
explain the jumbled ice sculptures. "Fracturing
catastrophically disrupts the ice in the same way that it causes ice shelves to
collapse on Earth, " Schmidt told Science News. She and her team found that the
process could be causing chaos terrains to form quickly on Europa.
The new study suggests that on this moon, elements such as oxygen from
the surface blend with the deep bodies of water. That mixture may create an
environment that supports life. The existence of liquid water is a necessity for a life-support