Hubble has found even more evidence of water vapor plumes
on the ocean world Europa. Last September we announced that the
Hubble Space Telescope had taken multiple images of what could be
water vapor plumes on Jupiter’s moon, Europa - an icy world
that’s thought to have a subsurface global ocean of
water. That same team of astronomers has now taken
additional ultraviolet images of probable plumes on this icy
moon. While these plumes seem intermittent, they appear to
have repeated in the same location. Pieces of the puzzle
of what’s going on with Europa are continuing to come together.
When the Galileo spacecraft was orbiting Jupiter in the late 90s
and early 2000s, it gathered data to build a thermal map of
Europa, and it appears the water vapor plumes Hubble is observing
correspond with a relatively warm region on Europa’s southern
surface about 200 miles across. This thermal anomaly the Galileo
spacecraft observed suggested geologic activity was happening
in this location, a conclusion now further supported by
Hubble’s recent observations of water vapor plumes. This
phenomenon may be similar to what the Cassini spacecraft has
seen at Saturn’s moon Enceladus, where there are also water vapor
plumes associated with warm regions on the moon’s surface.
The warm spot on Europa has a couple possible explanations.
Perhaps this location is warmed by liquid water a mile under the
surface pushing up through cracks in the ice. Or perhaps
the fine mist that’s falling from the water vapor plume
changes the structure of the surface ice grains, allowing
them to retain heat longer than the surrounding landscape. Now
that Hubble has shown Europa probably has water vapor plumes
associated with warm spots on its surface, this information
will be used for planning NASA's upcoming Europa Clipper mission.
Europa Clipper will be able to take up-close observations of
these probable plumes Hubble identified, and will be equipped
with instruments that can detect any additional warm spots and
water vapor plumes. This will provide insight into Europa’s
chemistry, geology, and potential conditions for
harboring alien life.
www.nasa.gov/hubble @NASAHubble