Thanks for the great question.
All living things convert energy in their
environment into a form that the organism uses to
grow and survive. Living things called
heterotrophs (like all animals) do this by
consuming other organisms to obtain energy.
Autotrophs, on the other hand, can directly
transform energy from non-biological sources, for
instance when plants convert sunlight into
chemical energy through photosynthesis.
In 1977, new types of autotrophs were
discovered living around hydrothermal vents at the
bottom of the ocean. These organisms, including
the giant tube worm, convert energy from chemicals
produced by these volcanic hot spots through a
process called chemosynthesis. This process
allows these organisms to use chemicals like
sulfur or hydrogen to create sugars and amino
acids, or the energy and materials that build up
their bodies. Chemosynthesis therefore
allows organisms to live in places that were
previously thought to impossible for life.
The ability of these organisms to use chemicals
instead of sunlight for energy radically changed
our understanding of how and where life can
thrive. In fact, scientists have now proposed that
life on worlds other than Earth, for instance Mars
or Jupiter’s moon Europa, may use chemosynthesis
to exist without energy from the sun.