Scientists
use the Earth as a tool for astrobiology by analysing planetary
field
analogues
(i.e. terrestrial samples and field sites that resemble planetary bodies in
our
Solar System)
.
In addition, they
expose the selected
planetary
field
analogues
in
simulation chambers
to
conditions
that mimic the ones
of planets, moons and Low Earth Orbit (LEO) space
conditions
, as well as
the
chemistry occurring in interstellar and cometary ices
.
This paper
reviews the ways the Earth is used by astrobiologists: (i) by conducting
planetary
field
analog
ue
studies to investigate extant life from extreme environments, its metabo
lisms,
adaptation strategies and modern biosignatures; (ii) by conducting
planetary
field
analog
ue
studies to investigate extinct life from the oldest rocks on our planet and its
biosignatures; (iii) by exposing terrestrial samples to simulated space or pl
anetary
environments and producing a sample analog
ue
to investigate changes in minerals,
biosignatures and microorganisms.
T
he European Space Agency (ESA) created a topical
team
in 2011
to investigate
recent activities using
the Earth as a tool for
a
strobi
ology
and
to formulate recommendations and scientific needs to improve ground
-
based
astrobiological research. Space is an important tool for astrobiology (see
Horneck et al.,
2016
;
Cottin et al, submitted), but access to space is limited. Complementing res
earch on
Earth provides fast access, more replications and higher sample throughput.
The major
conclusions of the
topical
team and suggestions for the future
include
more scientifically
qualified calls for field campaigns with planetary analogy
,
and a cent
ralized point of contact at ESA or
the
EU for the organization o
f
a survey of such expeditions. An
improvement of
the
coordinated logistics,
infrastructures
and funding system supporting
the combination of
field work with planetary simulation investigation
s
,
as well as an
optimization of
the
scientific return and data processing, data storage and data distribution
is
also
needed
.
Finally, a
coordinated EU or ESA education and outreach program would
improve the participation of the public
in the astrobiologi
cal activities.