9,575 research outputs found
Astrobiology and Society in Europe Today
This book describes the state of astrobiology in Europe today and its relation to the European society at large. With contributions from authors in more than 20 countries and over 30 scientific institutions worldwide, the document illustrates the societal implications of astrobiology and the positive contribution that astrobiology can make to European society. The book has two main objectives:
1. It recommends the establishment of a European Astrobiology Institute (EAI) as an answer to a series of challenges relating to astrobiology but also European research, education, and society at large.
2. It also acknowledges the societal implications of astrobiology, and thus the role of the social sciences and humanities in optimizing the positive contribution that astrobiology can make to the lives of the people of Europe and the challenges they face
Spectral signatures of photosynthesis I: Review of Earth organisms
Why do plants reflect in the green and have a 'red edge' in the red, and
should extrasolar photosynthesis be the same? We provide: 1) a brief review of
how photosynthesis works; 2) an overview of the diversity of photosynthetic
organisms, their light harvesting systems, and environmental ranges; 3) a
synthesis of photosynthetic surface spectral signatures; 4) evolutionary
rationales for photosynthetic surface reflectance spectra with regard to
utilization of photon energy and the planetary light environment. Given the
surface incident photon flux density spectrum and resonance transfer in light
harvesting, we propose some rules with regard to where photosynthetic pigments
will peak in absorbance: a) the wavelength of peak incident photon flux; b) the
longest available wavelength for core antenna or reaction center pigments; and
c) the shortest wavelengths within an atmospheric window for accessory
pigments. That plants absorb less green light may not be an inefficient legacy
of evolutionary history, but may actually satisfy the above criteria.Comment: 69 pages, 7 figures, forthcoming in Astrobiology March 200
Ethics and the potential conflicts between astrobiology, planetary protection and commercial use of space
A high standard of planetary protection is important for astrobiology, though the risk for contamination can never be zero. It is therefore important to find a balance. If extraterrestrial life has a moral standing in its own right, it will also affect what we have to do to protect it. The questions of how far we need to go to protect extraterrestrial life will be even more acute and complicated when the time comes to use habitable worlds for commercial purposes. There will also be conflicts between those who want to set a world aside for more research and those who want to give the green light for development. I believe it is important to be proactive in relation to these issues. The aim of my project is therefore to identify, elucidate, and if possible, suggest solutions to potential conflicts between astrobiology, planetary protection, and commercial use of space
The UK Centre for Astrobiology:A Virtual Astrobiology Centre. Accomplishments and Lessons Learned, 2011-2016
Authors thank all those individuals, UK research councils, funding agencies, nonprofit organisations, companies and corporations and UK and non-UK government agencies, who have so generously supported our aspirations and hopes over the last 5 years and supported UKCA projects. They include the STFC, the Engineering and Physical Sciences Research Council (EPSRC), the Natural Environmental Research Council (NERC), the EU, the UK Space Agency, NASA, the European Space Agency (ESA), The Crown Estate, Cleveland Potash and others. The Astrobiology Academy has been supported by the UK Space Agency (UKSA), National Space Centre, the Science and Technology Facilities Council (STFC), Dynamic Earth, The Royal Astronomical Society, The Rotary Club (Shetlands) and the NASA Astrobiology Institute.The UK Centre for Astrobiology (UKCA) was set up in 2011 as a virtual center to contribute to astrobiology research, education, and outreach. After 5 years, we describe this center and its work in each of these areas. Its research has focused on studying life in extreme environments, the limits of life on Earth, and implications for habitability elsewhere. Among its research infrastructure projects, UKCA has assembled an underground astrobiology laboratory that has hosted a deep subsurface planetary analog program, and it has developed new flow-through systems to study extraterrestrial aqueous environments. UKCA has used this research backdrop to develop education programs in astrobiology, including a massive open online course in astrobiology that has attracted over 120,000 students, a teacher training program, and an initiative to take astrobiology into prisons. In this paper, we review these activities and others with a particular focus on providing lessons to others who may consider setting up an astrobiology center, institute, or science facility. We discuss experience in integrating astrobiology research into teaching and education activities.Publisher PDFPeer reviewe
Identifying Planetary Biosignature Impostors: Spectral Features of CO and O4 Resulting from Abiotic O2/O3 Production
O2 and O3 have been long considered the most robust individual biosignature
gases in a planetary atmosphere, yet multiple mechanisms that may produce them
in the absence of life have been described. However, these abiotic planetary
mechanisms modify the environment in potentially identifiable ways. Here we
briefly discuss two of the most detectable spectral discriminants for abiotic
O2/O3: CO and O4. We produce the first explicit self-consistent simulations of
these spectral discriminants as they may be seen by JWST. If JWST-NIRISS and/or
NIRSpec observe CO (2.35, 4.6 um) in conjunction with CO2 (1.6, 2.0, 4.3 um) in
the transmission spectrum of a terrestrial planet it could indicate robust CO2
photolysis and suggest that a future detection of O2 or O3 might not be
biogenic. Strong O4 bands seen in transmission at 1.06 and 1.27 um could be
diagnostic of a post-runaway O2-dominated atmosphere from massive H-escape. We
find that for these false positive scenarios, CO at 2.35 um, CO2 at 2.0 and 4.3
um, and O4 at 1.27 um are all stronger features in transmission than O2/O3 and
could be detected with SNRs 3 for an Earth-size planet orbiting a
nearby M dwarf star with as few as 10 transits, assuming photon-limited noise.
O4 bands could also be sought in UV/VIS/NIR reflected light (at 0.345, 0.36,
0.38, 0.445, 0.475, 0.53, 0.57, 0.63, 1.06, and 1.27 um) by a next generation
direct-imaging telescope such as LUVOIR/HDST or HabEx and would indicate an
oxygen atmosphere too massive to be biologically produced.Comment: 7 pages, 4 figures, accepted to the Astrophysical Journal Letter
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