Explanation:
Although the phase
of this moon might appear familiar, the moon itself might not.
In fact, this
gibbous phase shows
part of
Jupiter's moon
Europa.
The robot spacecraft
Galileo captured
this image mosaic during its
mission orbiting Jupiter from 1995 - 2003.
Visible are plains of
bright ice,
cracks that run to the horizon, and
dark patches
that likely contain both ice and dirt.
Raised terrain is
particularly apparent near the
terminator,
where it casts shadows.
Europa is nearly the same size as
Earth's Moon, but much smoother, showing few
highlands or
large impact craters.
Evidence and images from the
Galileo spacecraft,
indicated
that liquid oceans might exist below the icy
surface.
To test speculation that these seas hold life,
ESA has
started preliminary development of the
Jovian
Europa Orbiter, a spacecraft proposed to orbit Europa.
If the surface ice is thin enough, a future mission might drop
hydrobots to burrow into the oceans
and search for life.
