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OATS-DAUT SEMINAR
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Speaker:
Julian CHELA-FLORES (ICTP-Trieste)
Title:
Astrobiology and Astronomy: Their Common Frontiers
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Abstract:
The new science of astrobiology studies the origin, evolution,
distribution and destiny of life in the universe. It is these last two
aspects of astrobiology (distribution and destiny) that have a common
frontier with astronomy and other space sciences. We begin with
bioastronomy: it concerns mainly the search for life in our galaxy by
means of radio and optical astronomy. A more recent aspect of the
joint research of astronomers and astrobiologists is restricted to the
Solar System, where an important factor for understanding the origin
and evolution of life on Earth, and possibly elsewhere, is the
evolution of the Sun itself. We consider constraints on the emergence
of life imposed by our knowledge of the early Solar System. We take
into account the biogeochemistry associated with the fractionation of
the stable isotopes of the biogenic elements, especially sulfur. The
presence of ultraviolet radiation on the early Earth is confronted
with the possibility that microorganisms, as we know them from
contemporary biota, could originate, survive, and evolve even under
the effect of harsher earlier solar radiation. Finally, we discuss the
search for a second example of life that would improve our
understanding of its origin. We discuss possible solar missions that
could clarify whether life could have emerged not only on the early
Earth, but also on Europa, the Galilean satellite.
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