A new study shows that changes in the oxygen content at the ocean's surface may have led to an extinction event at the end of the Triassic. Image Credit: NASA
Researchers studying ocean chemistry around the end-Triassic extinction (ETE) event have revealed new details about how oxygen availability in ocean water could have disrupted Earth’s nitrogen cycle and the ecological turnover in certain groups of organisms. Their results provide the first evidence for what is known as photic zone euxinia (PZE) associated with this event in Earth’s history. The scientists report that if the conditions they found ...June 4, 2015 / Written by: Aaron Gronstal
Drawing of Faraday disk, the first homopolar generator, invented by British scientist Michael Faraday in 1831. Credit: Émile Alglave & J. Boulard (1884) The Electric Light: Its History, Production, and Applications
Poynting’s theorem deals with the conservation of energy in a electromagnetic field, and is typically applied to stationary circuits or circuit elements. A team of researchers has now applied the theorem to the homopolar generator. Instead of being stationary, the homopolar generator is a conductor moving in a background magnetic field. Their results reveal new information about how magnetic braking arises within Poynting’s theorem.
The study was supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program.June 3, 2015 / Written by: Aaron Gronstal
NASA's Wide-field Infrared Survey Explorer, or WISE, captured this colorful image of the reflection nebula IRAS 12116-6001. This cloud of interstellar dust cannot be seen directly in visible light, but WISE's detectors observed the nebula at infrared wavelengths. Image Credit: NASA/JPL-Caltech/UCLA
Researchers have developed a numerical model that could provide information about how hydrogen molecules diffuse on the surface of ice mantles on interstellar grains. Ice mantles cover the core of dust grains in dense interstellar clouds, and usually the main component of these mantles is water. According to the scientists, the method could be particularly ...June 2, 2015 / Written by: Aaron Gronstal
Right: This Xenophora snail from the Pliocene Epoch shows how it finds a way to survive by incorporating shelly material from other organisms into its own shell. Left: Bulk sample of several ancient bivalves (clams) and gastropods (snails). Credit: University of Cincinnati
Researchers have produced a model of epoch-to-epoch changes in marine bivalves and gastropods during the Cenozoic period (65 million years go to present), providing a view of changes in distribution from tropical latitudes toward the Earth’s poles over time. The results show that climate change through the Cenozoic period had little effect on the migration patterns of ...June 1, 2015 / Posted by: Aaron Gronstal
NASA’s Curiosity rover is among those machines that have discovered signs of ancient water on Mars. Credit: NASA/JPL-Caltech/Univ. of Arizona
Mars is a large enough planet that astrobiologists looking for life need to narrow the parameters of the search to those environments most conducive to habitability.
NASA’s Mars Curiosity mission is exploring such a spot right now at its landing site around Gale Crater, where the rover has found extensive evidence of past water and is gathering information on methane in the atmosphere, a possible signature of microbial activity.
But where would life ...
NJ phylogram, starting with 172 representative taxa, limited to only the 23 taxa found in the agreement subtrees for the 100 replicate trees formed using iterations of six predicted orthologs. Credit: Figure 8, House et. al. (2015)
Astrobiologists studying microbial genomes have found that determining the order of genes in an organism’s DNA could provide insight into how genomes from different organisms are related. The team took a large selection of prokaryotic genomes and developed a method for determining how closely the genomes were related to one another based on the conservation of gene order. In doing so, they ...May 29, 2015 / Written by: Aaron Gronstal
This National Weather Service photo depicts a turbulent sea surface in the North Pacific during a storm. Credit: NOAA/Historic National Weather Service Collection
Current models of ocean redox on Earth suggest that anoxygenic photosynthesis in marine environments was more prevalent during Earth’s earliest time span (Precambrian) than during Earth’s current geological eon (Phanerozoic). To examine this theory, a team of scientists looked at products from carotenoid pigments in rock extracts and oils over a time period ranging from the Proterozoic (just before the rise of complex life) to the Paleogene (roughly 23 million years ago).
Carotenoids are ...May 28, 2015 / Written by: Aaron Gronstal
Rumuruti (R) chondrites have been recognized as a chondrite group since 1994. The first R chondrite was found in Australia in 1977 and is known as the Carlisle Lakes R chondrite. Above are thin sections from Carlisle Lakes in plane-polarized light (left) and cross-polarized light (right). Image Credit: NASA JPL
Many theories about the origins of life involve the delivery of organic molecules to the early Earth by objects from space. Previously, scientists have identified amino acids in carbon-rich meteorites. The abundance and structure of these amino acids can be very different depending on what type of meteorite they come ...May 28, 2015 / Written by: Aaron Gronstal
A molecular dynamics simulations of a transmembrane ion channel. Credit: Pohorille et al. 2010
Scientists supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program have used computer simulations and an electrodiffusion model to compute the conduction of simple ion channels.
Ion channels are pore-like structures in cell membranes that regulate how ions move in and out of cells. In humans, everything from brain function to muscle contraction relies on ion channels. They are also essential in lower organisms, and help protect cells from toxins and antimicrobial agents.
Ion channels are a basic mechanism found in all living organisms, and studying them could provide astrobiologists with important information about the origin and evolution of life on Earth. In addition, this research could have many applications in fields like biotechnology and medicine.
The study, “Calculating Conductance of Ion Channels – Linking Molecular Dynamics and Electrophysiology ,” was published in the journal Journal of Physics: Conference Series.
Source: [Journal of Physics: Conference Series]May 27, 2015 / Written by: Aaron Gronstal
A view of a hydrothermal vent at the Main Endeavour Field on the Juan de Fuca Ridge, snapped from the submersible Alvin. Credit: Woods Hole Oceanographic Institution
Scientists are studying barnacles that live around deep-sea hydrothermal vents in order to better understand the origin, dispersal and diversity of life in these environments. The study, supported in part by the Astrobiology Science & Technology Instrument Development (ASTID) element of the Astrobiology Program, indicates that barnacles have colonized deep-sea vents at least twice in history. A major lineage of barnacles that we see today originated in the western Pacific ocean during the Cenozoic, and then spread eastward through the Southern Hemisphere during the Neogene.
Information about how and when barnacles became dispersed around Earth’s vents provides clues about the dispersal of other deep-sea organisms, and how the distribution of organisms shaped the diversity of vent ecosystems. The results could also help scientists assess the effects of human disturbances on life deep below ...May 27, 2015 / Written by: Aaron Gronstal
It is in dense clouds of interstellar dust, gas, and ice like the Keyhole Nebula (above) that new stars and planetary systems are formed. This image of the Keyhole nebula comes from the Hubble Space Telescope. Credit: NASA and the Hubble Heritage Team (STSci), Hubble Space Telescope WFPC2, STSci-PRC00-06
Glycerol is a key building block of cell membranes, but scientists have not been able to explain its existence on early Earth. A study supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program shows that glycerol might form when ionizing radiation interacts with interstellar ices.
Following this radiation-induced formation of glycerol, interstellar grains can then be incorporated into the building material of solar systems. From here, the team believes that comets and meteorites could serve to deliver the glycerol to habitable planets like the early Earth.
The study, “Synthesis of Prebiotic Glycerol in Interstellar Ices,” was published in the journal Angewandte Chemie.
Source: [Angewandte Chemie]May 26, 2015 / Written by: Aaron Gronstal
NASA’s Curiosity rover has detected methane on Mars. Could the gas be coming from the rover itself? Credit: NASA/JPL
Is the Red Planet giving off methane?
The question has taunted scientists for nearly 50 years, ever since the Mariner 7 spacecraft detected a whiff of the gas near Mars’ south pole. Researchers retracted the finding a month later after realizing that the signal was in fact coming from carbon dioxide ice.
Then in 2003 and 2004, earthbound telescopes and orbiting spacecraft rekindled the mystery with reports of large methane clouds in Mars’ atmosphere. Most of ...
Derek Briggs awarded Paleontological Society Medal. Credit: YaleNews
The Paleontological Society named Derek Briggs its 2015 Paleontological Society Medalist for his work in the taphonomy, preservation and evolutionary significance of exceptionally preserved fossil biotas.
Briggs is a member of the NAI CAN-6 team at MIT, serving as a Co-I for the Foundations of Complex Life research project. He is also a professor of geology and geophysics at Yale University and curator of the Yale Peabody Museum of Natural History. His previous honors include the Premio Capo d’Orlando, the Lyell Medal, the Boyle Medal, and Humboldt Research Award.
More information ...May 21, 2015 / Written by: Miki Huynh
Astrobiology: The Story of our Search for Life in the Universe. Credit: NASA Astrobiology Program
Today, May 21st, NASA Astrobiology joins The Cartoon Art Museum in downtown San Francisco as they explore the theme of outer space through the medium of comic art. Visitors to this Third Thursday event will be able to pick up copies of the Astrobiology graphic history series by Aaron Gronstal in an exhibit featuring both works of science and science fantasy.
The event takes place 5:00-8:00PM and is free and open to the public.
Established in 1984, the Cartoon Art Museum displays and ...
The Mid-Cayman rise is an undersea ridge in the Caribbean Sea located at the tectonic boundary of the North American Plate and the Caribbean Plate. Credit: NOAA
By studying shrimp near hydrothermal vents, astrobiologists are learning about the sources of carbon in ecosystems of the Mid-Cayman rise.
Most life on Earth uses organic carbon produced by photosynthesis, a process that relies on energy from the Sun. However, in the dark depths of Earth’s oceans, hydrothermal vents support microorganisms that are able to produce organic carbon through chemosysnthesis. These microbes provide food for entire ecosystems that can survive independent of ...May 20, 2015 / Written by: Aaron Gronstal
- August 5 - Abstract Submission Deadline for American Geophysical Union (AGU) Fall Meeting
- August 5 - Direct Imaging of Habitable Exoplanets (Session P003) Abstract Submission Deadline for American Geophysical Union (AGU) Fall Meeting
- August 11 - Abstract Submission Deadline for Geological Society of America (GSA) 2015 Annual Meeting
- August 11 - Abstract Submission Deadline for Lunar Exploration Analysis Group (LEAG) Meeting
- August 15 - Registration Deadline for The Outer Planets Assessment Group (OPAG) Meeting
- August 20 - Abstract Submission Deadline for Astrobiology and Planetary Atmospheres 2015
- August 21 - Summer School at Moletai Observatory: "Formation and Evolution of Planetary Systems and Habitable Planets"
- August 24 - Berkner Autumn Program 2015
- September 2 - NRC Committee on Achieving Science Goals with CubeSats Symposium
- September 6 - Registration Deadline for Astrobiology and Planetary Atmospheres 2015
- September 15 - Registration Deadline for International Meeting: Missions to Habitable Worlds
- September 18 - Early Registration Deadline for K2 Science Conference (K2SciCon)
- September 18 - Abstract Submission Deadline for K2 Science Conference (K2SciCon)