Could a Saturn moon harbor life Carolyn Porco
two years ago here at Ted I reported
that we had discovered at Saturn with
the Cassini spacecraft an anomalously
warm and geologically active region at
the southern tip of the small Saturnian
moon Enceladus seen here this region
seen here for the first time in a
Cassini image taken in 2005 this is the
south polar region with the famous tiger
stripe fractures crossing the South Pole
and seen just recently in late 2008 here
is that region again now half in
darkness because the southern hemisphere
is experiencing the onset of August and
eventually winter and I also reported
that we’d made this mind-blowing
discovery this once-in-a-lifetime
discovery of towering Jets erupting from
those fractures at the South Pole
consisting of tiny water ice crystals
accompanied by water vapor and simple
organic compounds like carbon dioxide
and methane and at that time two years
ago I mentioned that we were speculating
that these Jets might in fact be geysers
and erupting from pockets or chambers of
liquid water underneath the surface but
we weren’t really sure
however the implications of those
results of a possible environment within
this moon that could support prebiotic
chemistry and perhaps life itself
we’re so exciting that in the
intervening two years we have focused
more on Enceladus we’ve flown the
Cassini spacecraft by this moon now
several times flying closer and deeper
into these Jets into the denser regions
of these Jets so that now we have come
away with some very precise
compositional measurements and we have
found that the organic compounds coming
from this moon are in fact more complex
and we previously reported while they’re
not amino acids we’re now finding things
like propane and benzene hydrogen
cyanide and formaldehyde and the tiny
water crystals here now look for all the
world like they are frozen droplets of
salty water which is a discovery that
suggests that not only do the Jets come
from
it’s of liquid water but that that
liquid water is in contact with rock and
that is a circumstance that could supply
the chemical energy and the chemical
compounds needed to sustain life so we
are very encouraged by these results and
we’re much more confident now than we
were two years ago that we might indeed
have on this moon under the South Pole
an environment or a zone that is
hospitable to living organisms whether
or not there are living organisms there
of course is an entirely different
matter and that will have to await the
arrival back at Enceladus of a
spacecraft hopefully sometime in the
near future specifically equipped to
address that particular question but in
the meantime I invite you to imagine the
day when we might journey to the
Saturnian system and visit the Enceladus
interplanetary geyser park just because
we can thank you