Archives

March 2016


The first scientific Roadmap for European Astrobiology was published on March 21st. This strategic landmark for European astrobiology has been produced through the European Commission-funded AstRoMap project (2013-2015).

A novel investigation of how enzymatic reactions can direct the motion and organization of microcapsules may point toward a new theory of how protocells - the earliest biological cells - could have organized into colonies and thus, could have ultimately formed larger, differentiated structures.

A new study brings into question the use of the molecule fullerene as a geologic indicator of impact events on ancient Earth.

We have identified iridium in an ~5 m-thick section of pelagic sediment cored in the deep sea floor at Site 886C, in addition to a distinct spike in iridium at the K-Pg boundary related to the Chicxulub asteroid impact.

Theoretical arguments indicate that close-in terrestial exoplanets may have weak magnetic fields. As described in the companion article (Paper I), a weak magnetic field results in a high flux of galactic cosmic rays to the top of the planetary atmosphere.

Viruses that infect bacteria are among the most abundant life forms on Earth. Indeed, our oceans, soils and potentially even our bodies would be overrun with bacteria were it not for bacteria-eating viruses, called bacteriophages, that keep the microbial balance of ecological niches in check.

Researchers from the J. Craig Venter Institute (JCVI) and Synthetic Genomics, Inc. (SGI) announced today the design and construction of the first minimal synthetic bacterial cell, JCVI-syn3.0.

Keith's note: I was deeply saddened to learn that my long time friend Ken Souza died suddenly yesterday. Ken was probably the first NASA life scientist I got to know when I started with NASA in the mid-1980s.

Penelope Boston has been selected as the director of NASA's Astrobiology Institute (NAI), in Moffett Field, California, to lead the scientific activities of the institute's member teams and all operational aspects of the organization. Her appointment is effective May 31.

Titan, with its thick, nitrogen-dominated atmosphere, has been seen from satellite and terrestrial observations to harbour methane clouds.

We present novel, analytical, equilibrium-chemistry formulae for the abundances of molecules in hot exoplanetary atmospheres that include the carbon, oxygen and nitrogen networks.

The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma.

Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, and a blanketing atmosphere. But life thrived thanks to another necessary ingredient: the presence of a protective magnetic field.

Keith's note: When I first came to Washington in 1986 I had the extreme pleasure of working with Thora at NASA Headquarters. Thora learned her craft from the very first people to send living things into space and I had the distinct honor of learning about those early days from her. She practically invented space biology. She was always fun to work with and had a soft spot when it came to young people. She was instrumental in the founding of ASGSB - now ASGSR - an organization which had the interests of students deeply embedded in its core mission.

Researchers have identified the first cold-adaptation proteins found in microbial mats from Lake Joyce, a perennially ice-covered lake in Antarctica.

As lower-mass stars often host multiple rocky planets, gravitational interactions among planets can have significant effects on climate and habitability over long timescales.

Over the past few years, astronomers have detected thousands of planets and planet candidates by observing their periodic transits in front of their host stars.

The dominant paradigm in assigning "habitability"' to terrestrial planets is to define a circumstellar habitable zone: the locus of orbital radii in which the planet is neither too hot nor too cold for life as we know it.

The temperature and density profiles of protoplanetary discs depend crucially on the mass fraction of micrometre-sized dust grains and on their chemical composition.

Are we alone in the universe? To answer this question, astronomers have been using a variety of methods in the past decades to search for habitable planets and for the signals from extraterrestrial observers.