• Target star catalog for Darwin: Nearby Stellar sample for a search for terrestrial planets, astro-ph
• NUV radii of the extrasolar planet HD 209458b, astro-ph
• Orbital Evolution of a Particle Interacting with a Single Planet in a Protoplanetary Disk, astro-ph
• Cold Storage for Alien Organisms

Posted by Keith Cowing at 1:54 PM | Permalink | Comments (0)

• CoRoT Measures Solar-Like Oscillations and Granulation in Stars Hotter Than the Sun, Science
• Epsilon Indi Ba, Bb: a spectroscopic study of the nearest known brown dwarfs, astro-ph
• The mass-radius relationship from solar-type stars to terrestrial planets: a review, astro-ph
• Resolved debris disk emission around eta Tel: a young Solar System or ongoing planet formation?, astro-ph

Posted by Keith Cowing at 6:20 PM | Permalink | Comments (0)

• Variability of the methane trapping in martian subsurface clathrate hydrates, astro-ph
• A slowly accreting ~10 Myr old transitional disk in Orion OB1a, astro-ph
• Effects of accretion flow on the chemical structure in the inner regions of protoplanetary disks, astro-ph
• The HARPS search for southern extra-solar planets XVII. Six long-period giant planets around BD -17 0063, HD 20868, HD 73267, HD 131664, HD 145377, HD 153950, astro-ph
• The Transit Light Curve Project. X. A Christmas Transit of HD 17156b, astro-ph
• The BAST algorithm for transit detection, astro-ph

Posted by Keith Cowing at 10:22 AM | Permalink | Comments (0)

• Solar System's Young Twin Has Two Asteroid Belts, Harvard-Smithsonian Center for Astrophysics
• Epsilon Eridani's Planetary Debris Disk: Structure and Dynamics based on Spitzer and CSO Observations, astro-ph
• Variability of the methane trapping in martian subsurface clathrate hydrates, astro-ph

Posted by Keith Cowing at 10:21 AM | Permalink | Comments (0)

• Planetary microlensing signals from the orbital motion of the source star around the common barycentre, astro-ph
• Mean Motion Resonances in Extrasolar Planetary Systems with Turbulence, Interactions, and Damping, astro-ph
• First-year students explore extraterrestrial life, UQ News
• Penn State Receives New NASA Astrobiology Grant, Penn State

Posted by Keith Cowing at 11:03 AM | Permalink | Comments (0)

• Mean Motion Resonances in Extrasolar Planetary Systems with Turbulence, Interactions, and Damping, astro-ph
• NASA Spaceline 26 September 2008 Current Space Life Science Awareness
• NASA Spaceline 19 September 2008 Current Space Life Science Awareness

Posted by Keith Cowing at 11:58 AM | Permalink | Comments (0)

• The statistics of accelerations seen in radial velocity searches for planets, astro-ph
• Dust in the inner regions of debris disks around A stars, astro-ph
• Abundance Stratification of Exoplanet Host Stars, astro-ph

Posted by Keith Cowing at 10:18 PM | Permalink | Comments (0)

• Spatially resolved 4.7 $\mu$m CO fundamental emission in two protoplanetary disks, astro-ph
• Modification of Angular Velocity by Inhomogeneous MRI Growth in Protoplanetary Disks, astro-ph
• New methods for large dynamical range problems in planetary formation, astro-ph
• Photochemical enrichment of deuterium in Titan's atmosphere: new insights from Cassini-Huygens, astro-ph
• Updated parameters for the transiting exoplanet WASP-3b using RISE, a new fast camera for the Liverpool Telescope, astro-ph
• Infrared Spectroscopy and Analysis of Brown Dwarf and Planetary Mass Objects in the Orion Nebula Cluster, astro-ph

Posted by Keith Cowing at 12:46 AM | Permalink | Comments (0)

• The Detectability of Exo-Earths and Super-Earths Via Resonant Signatures in Exozodiacal Clouds, astro-ph
• Time evolution of the line emission from the inner circumstellar ring of SN 1987A and its hot spots, astro-ph

Posted by Keith Cowing at 12:51 AM | Permalink | Comments (0)

The latest version of NASA's Astrobiology Roadmap and exciting reports on new strategies for detecting biosignatures in Earth rocks highlight the diverse content of the August 2008 (Volume 8, Number 4) issue of Astrobiology, a peer-reviewed journal published by Mary Ann Liebert, Inc. The latest version of NASAs Astrobiology Roadmap, a comprehensive document intended to guide and integrate research and technology development across groups from academia, government, and private institutions, is highlighted in this issue. The Roadmap defines research objectives aimed at answering three main questions: how does life begin and evolve; does life exist elsewhere in the universe; and what is the future of life on Earth and beyond?

Contents below

• Tribute to John F. Lindsay
• Introduction
• The NASA Astrobiology Roadmap
• Discovery of a New Chert-Permineralized Microbiota in the Proterozoic Buxa Formation of the Ranjit Window, Sikkim, Northeast India, and Its Astrobiolo
• Silicifying Biofilm Exopolymers on a Hot-Spring Microstromatolite: Templating Nanometer-Thick Laminae
• Amino Acids from Ion-Irradiated Nitrile-Containing Ices
• Using Electrical Impedance Spectroscopy to Detect Water in Planetary Regoliths
• Experiment LEND of the NASA Lunar Reconnaissance Orbiter for High-Resolution Mapping of Neutron Emission of the Moon
• Hairy Blobs: Microbial Suspects Preserved in Modern and Ancient Extremely Acid Lake Evaporites
• Was There a Late Archean Biospheric Explosion?
• Stable Iron Isotopes and Microbial Mediation in Red Pigmentation of the Rosso Ammonitico (Mid-Late Jurassic, Verona Area, Italy)
• Fluorescence Microscopy as a Tool for In Situ Life Detection

Posted by Keith Cowing at 12:26 AM | Permalink | Comments (0)

• NASA Supercomputer Shows How Dust Rings Point to Exo-Earths, NASA
• Tides Have Major Impact on Planet Habitability, University of Arizona
• Formation, evolution and multiplicity of brown dwarfs and giant exoplanets, astro-ph
• The Effect of Lunar-like Satellites on the Orbital Infrared Light Curves of Earth-analog Planets, astro-ph
• A Numerical Testbed for Hypotheses of Extraterrestrial Life and Intelligence, astro-ph

Posted by Keith Cowing at 12:07 AM | Permalink | Comments (0)

• Telescope Tech Will Speed Search for Extraterrestrial Life, Wired
• Core instability models of giant planet accretion II: forming planetary systems, astro-ph
• Rotational Line Emission from Water in Protoplanetary Disksastro-ph
• Tribute to John F. Lindsay, Astrobiology
• Introduction, Astrobiology
• The NASA Astrobiology Roadmap, Astrobiology
• Discovery of a New Chert-Permineralized Microbiota in the Proterozoic Buxa Formation of the Ranjit Window, Sikkim, Northeast India, and Its Astrobiolo, Astrobiology
• Silicifying Biofilm Exopolymers on a Hot-Spring Microstromatolite: Templating Nanometer-Thick Laminae, Astrobiology
• Amino Acids from Ion-Irradiated Nitrile-Containing Ices, Astrobiology
• Using Electrical Impedance Spectroscopy to Detect Water in Planetary Regoliths, Astrobiology
• Experiment LEND of the NASA Lunar Reconnaissance Orbiter for High-Resolution Mapping of Neutron Emission of the Moon, Astrobiology
• Hairy Blobs: Microbial Suspects Preserved in Modern and Ancient Extremely Acid Lake Evaporites, Astrobiology
• Was There a Late Archean Biospheric Explosion?, Astrobiology
• Stable Iron Isotopes and Microbial Mediation in Red Pigmentation of the Rosso Ammonitico (Mid-Late Jurassic, Verona Area, Italy), Astrobiology
• Fluorescence Microscopy as a Tool for In Situ Life Detection, Astrobiology

Posted by Keith Cowing at 12:35 AM | Permalink | Comments (0)

• Selection Functions in Doppler Planet Searches, astro-ph
• A Planet in a 0.6-AU Orbit Around the K0 Giant HD 102272, astro-ph
• A Distance-Limited Imaging Survey of Sub-Stellar Companions to Solar Neighborhood Stars, astro-ph

Posted by Keith Cowing at 10:14 PM | Permalink | Comments (0)

• Transiting exoplanets from the CoRoT space mission VI. CoRoT-Exo-3b: The first secure inhabitant of the brown-dwarf desert, astro-ph
• IAU Planet Definition: Some Confusions and Their Modifications, astro-ph
• Formation and Evolution of Planetary Systems (FEPS): Properties of Debris Dust around Solar-type Stars, astro-ph

Posted by Keith Cowing at 12:03 AM | Permalink | Comments (0)

• COROT discovery stirs exoplanet classification rethink, ESA
• Rock Offers Mirror-Image Clues to Life's Origins, Washington Post
• Cassini Flyby of Saturn Moon to offer Insight into Solar System History, University of Michigan
• NASA Cassini Plans Doubleheader Flybys of Saturn's Geyser Moon Enceladus, NASA

Posted by Keith Cowing at 10:52 PM | Permalink | Comments (0)

• Clathration of Volatiles in the Solar Nebula and Implications for the Origin of Titan's atmosphere, astro-ph
• Stellar wobble caused by a binary system: Can it really be mistaken as an extra-solar planet?, astro-ph
• Saturn Forms by Core Accretion in 3.4 Myr, astro-ph

Posted by Keith Cowing at 1:55 PM | Permalink | Comments (0)

The NAI supports postdoctoral fellows hosted at NAI teams through the NASA Postdoctoral Program (NPP). The NPP provides talented postdoctoral scientists and engineers with valuable opportunities to engage in ongoing NASA research programs and serves as a source of talent to ensure the continued quality of the NASA research workforce. The deadline for the next round of applications is November 1. For more information on the program, please see http://astrobiology.nasa.gov/nai/funding/nai-postdoctoral-fellowship-program/ and http://nasa.orau.org/postdoc .

As a reminder, all current NAI advisors, from CAN 3 and CAN 4 teams, are eligible as advisors to host postdoctoral fellows.

Source: NAI Newsletter

Posted by Keith Cowing at 7:05 PM | Permalink | Comments (0)

Researchers from NAI's University of Arizona team and their colleagues at the University of Leeds have a new paper in Angewandte Chemie International Edition dealing with prebiotic chemistry and the early Earth. Working both experimentally and with models of the early atmosphere, the team shows that the Hadean and early Archaean Earth was primed with an abundance of condensed phosphates, enabling the formation of the necessary precursors of RNA and DNA. This research removes one of the large stumbling blocks in prebiotic chemistry- that the early Earth lacked a low-temperature reservoir of activated phosphate compounds capable of eventually leading to the origin of life.

Source: NAI Newsletter

Posted by Keith Cowing at 7:04 PM | Permalink | Comments (0)

Members of NAI's Penn State, Carnegie Institution, and MIT teams report in a recent issue of Earth and Planetary Science Letters, the distribution of biomarkers in 2.72-2.56 billion-year-old, Neoarchean rocks from the Hamersley Province on the Pilbara Craton in Western Australia. Their observations are consistent with a cyanobacterial source for 2-methylhopanes, in which cyanobacteria were likely the cornerstone of microbial communities in shallow-water ecosystems providing molecular oxygen, fixed carbon, and possibly fixed nitrogen.

Their data, revealing relative abundances of 3-methylhopanes, but not 2-methylhopanes, strongly correlate to stable carbon isotopic composition of insoluble particulate organic matter (kerogen). The unanticipated nature of this relationship provides evidence for a shallow-water locus of carbon cycling through aerobic oxidation of methane and, coincidentally, a means to demonstrate biomarker syngenicity.

Source: NAI Newsletter

Posted by Keith Cowing at 7:03 PM | Permalink | Comments (0)

Researchers from NAI's University of Hawai'i team have a paper in the September 17 edition of Nature about the evolution of the animal gut. For more than 100 years zoologists have speculated about scenarios of how the bilaterally symmetrical animals (animals that have a left and a right side, like flies, fish, and humans) evolved from a simple circular (radially symmetric) ancestor that looked similar to jelly fish or corals. In the commonly presented scenarios this transition is connected to the evolution of a through-gut with an anterior mouth and posterior anus. It has been thought that both openings emerged simultaneously from a single embryological opening through which the inner tissues enter (called blastopore).

Recent molecular phylogenies however, place the marine acoel flatworms at the base of the bilaterally symmetric animals. Acoels are thus survivors from the Pre-Cambrian era that retain many ancestral characters (e.g. a nervous system composed of multiple nerve cords and only one opening to their digestive system). One can see Acoels as an evolutionary stepping stone that offers clues about the sequence of character evolution of bilateral animals.

To find out how the acoel digestive system, with its single opening ("mouth"), is related to the through gut present in some bilaterians like humans and flies, the researchers looked at the expression patterns of genes that play a role in the formation of both the mouth and the anus in bilaterian animals.

They were able to show that the sac-like gut of the bilaterian ancestor possessed a single opening that was inherited as the mouth in such diverse animals like flies and sea stars. Furthermore, the team accumulated evidence from gene expression patterns that the anal orifice evolved independently in different animal lineages, possibly in association with the gonoduct (the duct through which eggs and sperm are released). The independent evolution of the anus can be explained by the increase in body size and an elongation of the body. Increased energetic needs and a long blind gut would have made sorting food and waste through a single opening inefficient.

Their work, in conjunction with a better understanding of the evolutionary relationships of animals, clearly rejects previous ideas found in every zoology text book about the evolution of the last common ancestor of flies and humans from a radial symmetric animal (e.g. the Gastraea-Hypothesis of Ernst Haeckel). The team states that this ancestor that lived over 550 myr ago, before the radiation of the bilateral animals was far less complex morphologically than previously thought. At this time our ancestors were hermaphroditic worms, that had only a mouth and no anus. We literally had to spit out our undigested food. Our ancestor was likely a very small, soft-bodied animal that lived between the sand grains in the ocean, similar to the life-style of most acoel species. This also explains why no fossils have yet been found of these animals. The team is certain that their ongoing studies of the nervous system of these worms will yield to similar important insights into the evolutionary roots of the human brain and spinal cord.

Source: NAI Newsletter

Posted by Keith Cowing at 7:03 PM | Permalink | Comments (0)

Astrophysicists from the NAI's Carnegie Institution of Washington team and their colleagues have shown for the first time that a supernova could have triggered the solar system's formation under conditions of rapid heating and cooling. For several decades, scientists have thought that the solar system formed as a result of a shock wave from an exploding star--a supernova--that triggered the collapse of a dense, dusty gas cloud that contracted to form the sun and the planets. But detailed models of this formation process have only worked under the simplifying assumption that the temperatures during the violent events remained constant. The results, published in the October 20, 2008, issue of the Astrophysical Journal, have resolved this long-standing debate.

Source: NAI Newsletter

Posted by Keith Cowing at 7:02 PM | Permalink | Comments (0)

Presenter: Rory Barnes
Date/Time: October 7, 2008 02:30 PM Pacific

Abstract: The first terrestrial-like exoplanets will likely be observed in tight orbits around low-mass stars. Conveniently, planets on these orbits receive about as much starlight as the Earth does from the Sun, and hence have to potential to be habitable. Such planets may also experience significant tidal forces from the star which can result in orbital decay, a specific planetary rotation, and significant internal heating. I describe how these phenomena are likely to impact habitability. In some cases orbital decay may result in planets moving too close to their star for habitability. For planets on non-circular orbits, rotation periods may be similar to the Earth's and hence may produce similar atmospheric circulation patterns.

Tidal heating may span the range from zero to well in excess of Io's, and hence can dramatically impact habitability. Further complicating the situation is the presence of additional companions which may drive large oscillations in the magnitudes of these effects. Taken together these processes suggest a scheme for categorizing planetary attributes based on the planetary system's architecture, including a refinement of the prerequisites for planetary habitability.

For more information and participation instructions: http://astrobiology.nasa.gov/nai/seminars/detail/131

Source: NAI Newsletter

Posted by Keith Cowing at 7:01 PM | Permalink | Comments (0)

NASA has awarded five-year grants, averaging $7 million each, to 10 research teams from across the country to study the origins, evolution, distribution, and future of life in the universe.

The interdisciplinary teams will become new members of the NASA Astrobiology Institute, located at NASA's Ames Research Center at Moffett Field, Calif. Teams from the University of Hawaii in Honolulu; Arizona State University in Tempe; the Carnegie Institution of Washington; Pennsylvania State University in University Park, Pa.; the Georgia Institute of Technology in Atlanta; and Rensselaer Polytechnic Institute in Troy, N.Y., have been selected as members. Teams from Ames, NASA's Goddard Space Flight Center in Greenbelt, Md., and two teams led by NASA's Jet Propulsion Laboratory in Pasadena, Calif., also have been selected.

"The research of these new teams reflects the increasing maturity of astrobiology," said NASA Astrobiology Institute Director Carl Pilcher of Ames. "They are focused on fundamental questions of life in the universe, but their work has implications for all of science. The research of these teams, together with that of the four continuing institute teams, will bridge the basic science of astrobiology to NASA's current and planned space exploration missions."

The University of Hawaii will investigate the origin, history, and distribution of water and its relation to life in the universe.

Arizona State University will develop new, more refined criteria to guide the search for life by characterizing life's elemental requirements. This will be developed by a "follow the elements" strategy for investigating habitability in extraterrestrial environments.

Carnegie Institution of Washington will conduct a wide range of research. They will focus on life's chemical and physical evolution, from the interstellar medium, through planetary systems, to the emergence and detection of life.

Rensselaer Polytechnic Institute will conduct a multifaceted, highly integrated, program of interdisciplinary research on setting the stage for life. This will focus on the origins of relevant molecules and habitable environments, and on the processes by which chemical evolution leads to life.

Pennsylvania State University will develop novel approaches to detecting and characterizing life. Investigations will include indicators or signatures of life in mission-relevant ecosystems and ancient rocks, and evaluating the potential for these signatures in extraterrestrial settings.

The Georgia Institute of Technology will pursue the scientific goal of rewinding the tape of life to before the last universal common ancestor of all living organisms. This could shed light on the nature of protein synthesis by the earliest living systems.

Ames will conduct a program of integrative, mission-enabling research to investigate the creation and distribution of early habitable environments in emerging planetary systems. Goddard will evaluate the possible role of organic material from space in the origin of life on Earth, and advance understanding of organics on other worlds.

The first of two JPL teams will be devoted to an interdisciplinary investigation of chemistry on Saturn's moon Titan. The team will focus on Titan's physical environment to provide a basis for understanding the chemistry of early Earth, which was the precursor for life. The second JPL team will investigate the habitability of icy worlds, such as Titan, and Saturn moons Europa and Enceladus. They also will investigate how life could be detected in such environments and begin to define related instrumentation for future missions.

"The new teams provide a superb foundation for the institute as it enters its second decade," said Jim Green, Planetary Science Division director at NASA Headquarters in Washington. "They bring together the many disciplines necessary for a comprehensive interdisciplinary approach to studying life in the universe."

The new members join four continuing teams led by Montana State University in Bozeman, the Massachusetts Institute of Technology in Cambridge, the University of Washington in Seattle, and the University of Wisconsin in Madison.

Posted by Keith Cowing at 6:33 PM | Permalink | Comments (0)

• Independent discovery and refined parameters of XO-5b: a hot Jupiter transiting a moderately faint star, astro-ph
• The Atmospheres of Extrasolar Planets, astro-ph
• The sub-Jupiter mass transiting exoplanet WASP-11b, astro-ph
• A New Spectroscopic and Photometric Analysis of the Transiting Planet Systems TrES-3 and TrES-4, astro-ph

Posted by Keith Cowing at 12:47 PM | Permalink | Comments (0)

Salle Cassini, Observatoire de Paris, November 19-21 2008

Exoplanets are being discovered at an ever accelerating pace. As a result planetary scientists and astronomers are increasingly called upon to make the transition from discovery to characterization, so that we can begin the long journey of understanding these planets in the same way that we understand those in our own Solar System. Among the known exoplanets, hot-Jupiters and hot-Neptunes that transit their parent stars present the first real opportunities to determine key compositional and atmospheric parameters.

The atmospheres of transiting hot-Jupiters are now starting to be probed for water vapour, carbon/nitrogen/sulphur bearing molecules. The results will provide us with a first insight on the photochemical composition and escape processes on the atmospheres of hot-Jupiters, and pave the way to do such studies on hot-Neptunes, super-Earths, and finally Earth-mass planets. This is a necessary step before proceeding with the study of cooler planets.

This workshop aims at bringing together different scientific communities : solar system planetary scientists, brown dwarf and exoplanet modellers and observers, molecular spectroscopy and instrument development experts. We will cover different topics : radiative transfer, line lists, photochemical models, dynamics, observations using ground based facilities (high-resolution spectroscopy in the optical and in the IR), and space-based observations. Present days results will be discussed in the context of the preparation of upcoming warm SPITZER, JWST, SPICA, and the next generation of direct detection mission concepts from ground and space.

For more information: http://www.iap.fr/molecules2008/

Source: NAI Newsletter

Posted by Keith Cowing at 7:06 PM | Permalink | Comments (0)