Tag Archives: life

New Study Outlines ‘Water World’ Theory of Life’s Origins

Life took root more than four billion years ago on our nascent Earth, a wetter and harsher place than now, bathed in sizzling ultraviolet rays. What started out as simple cells ultimately transformed into slime molds, frogs, elephants, humans and the rest of our planet’s living kingdoms. How did it all begin?

A new study from researchers at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and the Icy Worlds team at NASA’s Astrobiology Institute, based at NASA’s Ames Research Center in Moffett Field, Calif., describes how electrical energy naturally produced at the sea floor might have given rise to life. While the scientists had already proposed this hypothesis — called “submarine alkaline hydrothermal emergence of life” — the new report assembles decades of field, laboratory and theoretical research into a grand, unified picture. (more…)

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Ancient Minerals: Which Gave Rise to Life?

Washington, D.C.— Life originated as a result of natural processes that exploited early Earth’s raw materials. Scientific models of life’s origins almost always look to minerals for such essential tasks as the synthesis of life’s molecular building blocks or the supply of metabolic energy. But this assumes that the mineral species found on Earth today are much the same as they were during Earth’s first 550 million years—the Hadean Eon—when life emerged. A new analysis of Hadean mineralogy challenges that assumption. It is published in American Journal of Science.

Carnegie’s Robert Hazen compiled a list of every plausible mineral species on the Hadean Earth and concludes that no more than 420 different minerals—about 8 percent of the nearly 5,000 species found on Earth today—would have been present at or near Earth’s surface. (more…)

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If We Landed on Europa, What Would We Want to Know?

Most of what scientists know of Jupiter’s moon Europa they have gleaned from a dozen or so close flybys from NASA’s Voyager 2 spacecraft in 1979 and NASA’s Galileo spacecraft in the mid-to-late 1990s. Even in these fleeting, paparazzi-like encounters, scientists have seen a fractured, ice-covered world with tantalizing signs of a liquid water ocean under its surface. Such an environment could potentially be a hospitable home for microbial life. But what if we got to land on Europa’s surface and conduct something along the lines of a more in-depth interview? What would scientists ask? A new study in the journal Astrobiology authored by a NASA-appointed science definition team lays out their consensus on the most important questions to address.

“If one day humans send a robotic lander to the surface of Europa, we need to know what to look for and what tools it should carry,” said Robert Pappalardo, the study’s lead author, based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “There is still a lot of preparation that is needed before we could land on Europa, but studies like these will help us focus on the technologies required to get us there, and on the data needed to help us scout out possible landing locations. Europa is the most likely place in our solar system beyond Earth to have life today, and a landed mission would be the best way to search for signs of life.” (more…)

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From flounders to seahorses: Evolutionary success of spiny-rayed fishes detailed

Even as the dinosaurs were becoming extinct 66 million years ago, the ancient ancestor of spiny-rayed fishes flourished, eventually giving rise to tens of thousands of species that can now be found in home aquariums or on dinner plates. Using modern genetic tools and information from the fossil record, a team led by researchers at Yale University, University of Oxford, and University of California-Davis have constructed a detailed evolutionary history of the 18,000 species of spiny-rayed fishes existing today, a diverse group that includes basses, pufferfishes, and cichlids, and that comprises a large portion of the vertebrate tree of life.

The findings published the week of July 15 in the Proceedings of the National Academy of Sciences show surprisingly close evolutionary relationships between lineages of fish species such as tunas and seahorses, and suggest some fish lineages — like cichlids, the tiny gobies, and little-studied snailfishes — are experiencing high rates of new species origination. (more…)

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‘Life as Research Scientist’: Angel Byrd, Cell Biologist

For years, Brown University M.D./Ph.D. student Angel Byrd had dedicated herself to studying how immune system cells capture invading fungal pathogens. Like those cells, called neutrophils, she had seized on seemingly every opportunity that had come her way. (more…)

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NASA Rover Finds Conditions Once Suited for Ancient Life on Mars

PASADENA, Calif. –– An analysis of a rock sample collected by NASA’s Curiosity rover shows ancient Mars could have supported living microbes.

Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon — some of the key chemical ingredients for life — in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater on the Red Planet last month.

“A fundamental question for this mission is whether Mars could have supported a habitable environment,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “From what we know now, the answer is yes.” (more…)

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Life Possible on Extrasolar Moons

In their search for habitable worlds, astronomers have started to consider exomoons, or those likely orbiting planets outside the solar system. In a new study, a pair of researchers has found that exomoons are just as likely to support life as exoplanets.

The research, conducted by Rory Barnes of the University of Washington and the NASA Astrobiology Institute and René Heller of Germany’s Leibniz Institute for Astrophysics Potsdam, will appear in the January issue of Astrobiology. Heller is lead author of the paper. (more…)

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