Evaporating
Planet
Planet
HD 209458b
is
evaporating.
It is so
close to
its parent
star that
its heated
atmosphere
is simply
expanding
away into
space.
Some
astronomers
studying
this
distant
planetary
system now
believe
they have
detected
water
vapor
among the
gases
being
liberated.
This
controversial
claim, if
true,
would mark
the first
instance
of
planetary
water
beyond our
solar
system,
and
indicate
anew that
life might
be
sustainable
elsewhere
in the
universe.
Although
spectroscopic
observations
from the
Hubble
Space
Telescope
are the
basis for
the water
detection
claim, the
planetary
system is
too small
and faint
to image.
The image
is an
artist's
concept of
the HD
209458b
system.
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