Scanning electron micrographs of anaerobic Fe(II)-oxidizing cultures. From: Schadler et al. (2009) Formation of Cell-Iron-Mineral Aggregates by Phototrophic and Nitrate-Reducing Anaerobic Fe(II)-Oxidizing Bacteria, Geomicrobiology Journal.
A new study provides insight into a well-recognized chemolithotrophic pathway that can be used by microorganisms inhabiting anoxic sediments. Researchers used an enrichment culture of chemolithoautotrophic organisms from freshwater sediments (dubbed Culture KS) as a model system to study the pathway: nitrate-dependent ferrous iron [Fe(II)] oxidation (NDFO).
Previous efforts to isolate the organism responsible for the oxidation of iron [Fe(II)] in Culture KS had proven unsuccessful. In the new study, researchers used metagenomic analysis to better understand the roles of different bacteria in Culture KS. Using this method, they were able to identify the primary Fe(II)-oxidizer ...
Source: [Applied Environmental Microbiology]
The colored rings signify the different sectors where geoscientists work. The wedges, in turn, represent the fields where geoscientists are employed and include different examples of occupations. Where the wedges intersect with the rings indicate that those fields are included in those sectors. Image credit: Illustrator: Kathleen Cantner. Content: Heather Houlton & Abigail Seadler
The American Geosciences Institute (AGI) developed an infographic as a part of their Preparing Our Workforce (POW) Initiative to help students entering the workforce redefine what it means to have a career in geoscience. Having a successful geoscience career is not solely about mastering the technical fields of study, but includes how students seamlessly integrate their interests and competencies to build a professional portfolio that will bolster their geoscience career. Recognizing the importance of emphasizing the transferability of skills across different fields is imperative to students’ employability as geoscientists.
Source: [American Geosciences Institute ]May 18, 2016 / Written by: Julie Fletcher
A new study explores how properties of organization and cognition in the human brain could be universal. Researchers focused on semantics, or ‘meaning expressed through language,’ and developed an empirical measure of how semantics might reflect cultural, historical, and environmental backgrounds. The results highlight a universal structure underlying the sampled vocabulary across different language groups and largely independent of geography or environment.
Schematic of a bipartite semantic network constructed through translation (first layer to second layer) and back-translation (second layer to third layer) for MOON and SUN in two American languages: Coast Tsimshian (red) and Lakhota (blue).
Source: [PNAS]May 16, 2016 / Written by: Aaron Gronstal
In situ macro and mesostructure of Barstow Formation tufa. Image credit: Ibarra and Corsetti
The processes that govern the formation of stromatolites—structures that may represent macroscopic manifestation of microbial processes and a clear target for astrobiological investigation—occur at various scales (local versus regional), yet determining their relative importance remains a challenge, particularly for ancient deposits and/or if similar deposits are discovered elsewhere in the Solar System.
A new paper builds upon the traditional multiscale level approach of investigation (micro-, meso-, macro-, mega-) by including a lateral comparative investigational component of fine- to large-scale features to determine the relative significance of local and/or nonlocal controls on stromatolite morphology, and in the ...
Source: [Astrobiology]May 11, 2016 / Written by: Julie Fletcher
Our sun has a temperature of about 5800K. For stars cooler than our sun (M dwarfs at 3000-4000K) the habitable zone is closer in. For hotter stars (A dwarfs at 10,000K) the region is much farther out.
Researchers have provided new estimates for the inner edge of the habitable zone for synchronously rotating terrestrial planets around late-K and M-dwarf stars. Using a 3-D Earth-analog global climate model (GCM), the team has shed new light on the relationship between the rotational rates of planets and habitability around these types of stars. The results indicate that rotation rates for planets at the inner edge of the habitable zone become faster and that the inner edge is farther away from the host star than indicated in previous GCM studies.
The paper, “The inner edge of the habitable zone for synchronously ...
Source: [Earth and Planetary Astrophysics]May 09, 2016 / Written by: Aaron Gronstal
The iconic “pale blue dot” image of Earth taken by the Voyager 1 spacecraft, from a distance of 3.7 billion miles in 1990. Earth is the speck halfway down the brownish streak to the right. The streaks are artifacts, caused by the scattering of sunlight in the probe’s optics.
In 1990, Voyager 1 captured the most distant portrait of our planet ever taken, revealing that from beyond Pluto’s orbit Earth appears as nothing more than a “pale blue dot.” In a new study, researchers have tested whether Earth’s color is a unique feature of life-friendly planets. If so, searching for exoplanets displaying this hue could help in singling out worlds potentially brimming with alien life.
As it turns out, Earth’s delicate color can be closely mimicked by hypothetical exoplanet types that are completely uninhabitable. A broader portion of Earth’s overall spectrum, however, does display a ...
Source: [astrobio.net]May 06, 2016 / Written by: Adam Hadhazy
This low-angle self-portrait of NASA's Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target called "Buckskin." The MAHLI camera on Curiosity's robotic arm took multiple images on Aug. 5, 2015.
A new paper presents the case for updating the current planetary protection policy applied to “special regions on Mars” based on new information about Earth organisms. Mars’ “Special Regions” are areas where exploration missions must undergo strict planetary protection measures prior to launch due to the fact that environmental conditions in the region could be conducive to the growth of microorganisms from Earth.
The study, “Planetary Protection and Mars Special Regions – A Suggestion for Updating the Definition” was published in the journal Astrobiology. The work was supported by the NASA Astrobiology Institute (NAI) element of the NASA Astrobiology Program.
Source: [Astrobiology]May 02, 2016 / Written by: Aaron Gronstal
The NASA Astrobiology Program and the NASA Astrobiology Institute are pleased to announce the selections from two funding opportunities.
The NASA Postdoctoral Fellowship Program selected two Fellows from the November 2015 opportunity:
- Barbara Lafuente Valverde
Advisor: Thomas Bristow, NASA Ames Research Center (Habitable Worlds)
Topic: Use of clay minerals as paleoenvironmental indicators of the origin of Ediacaran multicellular life in the Doushantuo Formation
- Kazumi Ozaki
Advisor: Chris Reinhard, Georgia Institute of Technology (NAI, University of California, Riverside team)
Topic: New Quantitative Approaches Toward Understanding The Life History Of An Inhabited Planet
From the April 2016 NASA Astrobiology Institute Early Career ...April 28, 2016 / Written by: Julie Fletcher
- Barbara Lafuente Valverde
Researchers think emissions from volcanos, such as the one seen here, may have led to a dramatic rise in CO2 leading to a mass extinction 200 million years ago. (Photo/NASA Earth Observatory)
Just over 200 million years ago, long before the demise of the dinosaurs, a cataclysm killed off a significant chunk of the planet’s animal life. The leading theory implicates massive volcanic eruptions, triggered when the supercontinent of Pangea was ripped apart into separate continents.
A new study co-authored by USC researchers, including Yadira Ibarra, NAI/APS Lewis and Clark Fund for Exploration and Field Research in Astrobiology awardee, strengthens evidence for that theory and has wider implications for how rapid climate change can affect life on Earth. Along with lava flows, the volcanic eruptions released massive amounts of the ...
Source: [USC News]April 26, 2016 / Written by: Andrew Good
Astrobiology booth staffed by Jack Farmer and Sheri Klug both from ASU. Image Credit: Barbara Vance
Few places in the United States have night skies that are as dark and inviting as Death Valley. There are also very few places in the world where the extremes of our planet can offer a look into what may be possible in our Solar System and beyond. In conjunction with the National Park Service’s 100th anniversary, scientists and the public met in Death Valley for an opportunity to learn more about our planet and solar system, and to learn how that knowledge helps plan for humans to explore beyond Earth.
There are several planetary analog research sites within ...April 25, 2016 / Written by: Barbara Vance
In order to identify inhabited worlds beyond the Solar System, scientists are exploring the possibility of detecting gases that could serve as biosignatures in the atmospheres of extrasolar planets. Molecular oxygen (O2) and ozone (O3) have been suggested as the most robust individual biosignatures gases. However, it has been shown that these gases can also be produced without life through multiple abiotic mechanisms.
A new study discusses how other gases (CO and O4) in spectra from extrasolar planets could be used to discriminate between biotic and abiotic O2 and O3. The team of researchers produced ...
Source: [Earth and Planetary Astrophysics]April 19, 2016 / Written by: Aaron Gronstal
NAI Interim Director, Carl Pilcher, presented an overview of astrobiology to a public audience on the Big Island of Hawaii at the invitation of the Keck Observatory. This was one of a series of talks he presented to both the public and supporters of the Observatory as part of a week-long visit in late March 2016. In his presentation Carl discussed how astrobiology embraces and integrates five interconnected areas of science to provide a perspective on life as a cosmic phenomenon.
CLICK HERE to view the presentation.April 18, 2016 / Written by: Julie Fletcher
(Top row, left to right) Titan, Earth's moon, Europa and Enceladus. (Bottom row, left to right) Callisto, Charon, Ariel and lo. Image credit: NASA
On April 13, 2016 on NPR’s Morning Edition, Rory Barnes, member of the NAI University of Washington, VPL Team, talked about looking for life on alien moons.
“Finding a new planet that orbits a distant star isn’t such a big deal anymore — astronomers have discovered around 2,000. But no one knows if any of these planets has a moon.”
CLICK HERE to listen to the podcast or to read the transcript.
Source: [NPR]April 14, 2016 / Written by: Julie Fletcher
Earth’s thin atmosphere is all that stands between life on Earth and the cold, dark void of space.
Radiative transfer (RT) calculations are used in many applications for studying interactions between the Earth and its atmosphere, including remote sensing and climate modelling. One method, known as Principal Component Analysis (PCA), has been shown to increase computational speed while maintaining the accuracy of calculations over narrow spectral bands.
A new study has extended the PCA method for RT calculations over the entire shortwave region of the spectrum. The region from 0.3 to 3 microns is divided into 33 spectral fields, and covers all major gas absorption regimes.
The study, “A fast and accurate PCA based radiative transfer model ...April 12, 2016 / Written by: Aaron Gronstal
Astronaut photograph (ISS011-E-10575) of Yellowstone Lake from orbit. Geothermal features such as geysers and hot springs are located in the West Thumb area. This is thought to be due to a relatively shallow, local magma source.
A new interdisciplinary study evaluates microbial populations that inhabit thermal vents in Yellowstone Lake. Yellowstone Lake is a fresh-water system straddling a caldera, and experiences significant geothermal activity. Using a metagenome sequencing approach, researchers were able to study how waters from vents affected the distribution of specific microorganisms. Samples from the vents were obtained with a remotely operated vehicle.
Microorganisms with a range of metabolisms were studied in conditions that varied by the composition, temperature, and pH range of thermal waters. Novel groups of methanogens were also identified in the study. The research shows that the thermal vents in Yellowstone ...
Source: [Frontiers in Microbiology]April 10, 2016 / Written by: Aaron Gronstal
- May 26 - Registration Deadline for 26th Goldschmidt Conference
- May 26 - Application Deadline: ROSES 2016 Exoplanets Research Program
- May 31 - Early Registration Deadline for COSPAR 2016
- May 31 - Early Registration Deadline for 35th International Geological Congress
- June 1 - Abstract Submission Deadline for SoCIA 2016: An Interdisciplinary Workshop on Social and Conceptual Issues in Astrobiology
- June 1 - Registration Deadline for Exoplanets I Conference Series
- June 1 - Seminar: "Chemical Gardens, Chimneys, and Fuel Cells: Simulating Prebiotic Chemistry in Hydrothermal Vents on Ocean Worlds"
- June 3 - Abstract Submission Deadline for Lunar and Small Bodies Graduate Conference (LunGradCon)
- June 3 - Registration Deadline for Lunar and Small Bodies Graduate Conference (LunGradCon)
- June 3 - Application Deadline: ROSES 2016 Emerging Worlds
- June 10 - Registration closes for Astronomical Society of Australia Annual Scientific Meeting
- June 13 - Early Registration Deadline for Microscopy & Microanalysis 2016 Meeting
- June 14 - Application Deadline: Geomicrobiologist or Astrobiologist Position at NASA Johnson Space Center
- June 22 - Late Registration Deadline for Titan Aeronomy and Climate Workshop
- June 23 - Abstract Submission Deadline for Joint DPS-EPSC Meeting
- June 24 - Abstract Submission Deadline (Poster) for III Congreso Internacional de Astrobiología
- June 24 - Abstract Submission Deadline (Oral) for III Congreso Internacional de Astrobiología
- June 24 - Application Deadline: ROSES 2016 Laboratory Analysis of Returned Samples (LARS)
- NAI 2014 Annual Science Report