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Astrobiology is the study of the living universe. Advances in science and technology are yielding dramatic
new knowledge about the origin, distribution, and destiny of life. Scientists have analyzed complex organic chemistry in
interstellar clouds of gas and dust and have discovered more than 100 planets outside
of our solar system. Life on Earth has been found thriving at environmental extremes such as in Antarctic rocks, boiling hot springs, and aquifers buried kilometers below the land surface. We have found that
liquid water, the one essential ingredient for life as we know it, once flowed on the surface of the planet Mars and exists today below the icy crust of Jupiter's moon, Europa. Life on Earth has been traced back 3.8 billion years to the period of heavy cometary bombardment, an
era that simultaneously brought life-giving water and organic compounds to the terrestrial planets while battering them with
lethal quantities of impact energy. We are discovering both the fragility and robustness of life as we investigate the history of
mass extinctions on our planet (including extinctions taking place
today), the subtle alterations in climate triggered by volcanic eruptions and human industry, and the destruction of our planet's
protective shield of ozone.
Astrobiology is, then, a macro-system focussed discipline. It seeks to understand the very large scale processes which can
influence or even create life. The ramifications of the recent discovery that Mars was once quite wet has caused quite a stir in
the astrobiological community. More than this, an astrobiologist wants an answer to the question "How does life arise?" He may
model a galaxy's lifetime, or part of it, to see which stars are formed where, how they
orbit, and whether they avoid the energetic (and quite deadly) galactic center. Astrobiologists are interested in metallicity of
stars since a star with a high metallicity is very likely to have planets. This ties in
with the age of stars - An old star was formed before supernovae had enriched the
locale with metals. Astrobiology is truly a diverse discipline (being young), yet intensely relevant.
Astrobiology is multidisciplinary in its content and interdisciplinary in its execution. Its success depends critically upon
the close coordination of diverse scientific disciplines and programs, including space missions. The fundamental questions that
astrobiology attempts to answer are these:
- How do habitable worlds form and how do they evolve?
- How did living systems emerge? How can we recognize other biospheres?
- How have the Earth and its biosphere influenced each other over time?
- How do rapid changes in the environment affect emergent ecosystem properties and their evolution?
- What is the potential for biological evolution beyond the planet of origin?
Astrobiology encourages planetary stewardship through an emphasis on protection against forward and back biological
contamination and recognition of ethical issues associated with exploration.
Astrobiology recognizes a broad societal interest in its endeavors, especially in areas such as achieving a deeper
understanding of life, searching for extraterrestrial biospheres, assessing the societal implications of discovering other
examples of life, and envisioning the future of life on Earth and in space.
See also
List of stars
with known planetary systems
External links
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