focus on moons in
outer solar system
By Nadia Drake
The solar system’s spotted bully and its ringed sidekick are hold- ing some tantalizing treasures in their gravitational clutches.
Circling Jupiter and Saturn are more
than a hundred moons, including some
of the most promising hosts for extraterrestrial life in the solar system.
But not every one of these moons is an
equal opportunity extraterrestrial petri
dish. Scientists are now debating which
might be best for a life-seeking mission.
Their attention is focused on a frozen
trio: Titan, Enceladus and Europa.
For centuries, these satellites appeared
in the sky as mere points of light. Now,
the three moony musketeers have per-
sonalities. Enormous Titan is exotic, the
home of hydrocarbon lakes and a thick
atmosphere. Tiny Enceladus spits salty
water into the void around Saturn. And
deceptively placid, ice-crusted Europa
probably hosts a sloshing ocean so deep
it tickles the moon’s rocky mantle.
Some scientists rank the Saturnian
moon Enceladus as the best place
in the solar system to go looking for