Europa is the smallest
of Jupiter’s four Galilean moons. It was discovered by Galileo in 1610. German
astronomer Simon Marius also discovered it independently.
Europa has a
thin outer layer that is composed of an icy surface with unique linear ridges
and cracks. It is relatively smooth compared to other moons that bear large
craters due to numerous impacts throughout billions of years.
It is thought to
be composed of an iron core, a rocky mantle, and a salt water ocean on its
surface, similar to Earth. However, the ocean is much deeper and covers the
entire surface of the Moon. Since the moon is so far from the Sun, the ocean is
entirely frozen. On the other hand, some scientists argue that there is
possibly some liquid water under the thin frozen ice.
Europa is often said
to be the moon that is “likeliest to have life” because it is commonly believed
by scientists that liquid water oceans possibly lie beneath the thin outer icy
layer of surface; and, water, for humankind, has always been an indicator of
life, whether it is on Earth or on any place in our solar solar system.
Comparison to Earth’s moon:
It is slightly smaller
than Earth’s Moon and its orbit is phased locked around Jupiter, just like the
Moon to Earth. This is to say, according to NASA, “the same side of Europa
faces Jupiter at all times”. Europa also influences the tides of Jupiter.
Photograph of Europa taken by Galileo probe (NASA)
These lines adorn Europa’s icy surface
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