Tag Archives: sulfur

Before Dinosaurs’ Era, Volcanic Eruptions Triggered Mass Extinction

Increase in atmospheric carbon dioxide, global warming, ocean acidification killed 76 percent of species on Earth

More than 200 million years ago, a massive extinction decimated 76 percent of marine and terrestrial species, marking the end of the Triassic period and the onset of the Jurassic.

The event cleared the way for dinosaurs to dominate Earth for the next 135 million years, taking over ecological niches formerly occupied by other marine and terrestrial species.

It’s not clear what caused the end-Triassic extinction, although most scientists agree on a likely scenario. (more…)

Read More

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…)

Read More

NASA Mars Rover Preparing to Drill into First Martian Rock

PASADENA, Calif. — NASA’s Mars rover Curiosity is driving toward a flat rock with pale veins that may hold clues to a wet history on the Red Planet. If the rock meets rover engineers’ approval when Curiosity rolls up to it in coming days, it will become the first to be drilled for a sample during the Mars Science Laboratory mission.

The size of a car, Curiosity is inside Mars’ Gale Crater investigating whether the planet ever offered an environment favorable for microbial life. Curiosity landed in the crater five months ago to begin its two-year prime mission. (more…)

Read More

NASA Mars Rover Fully Analyzes First Soil Samples

PASADENA, Calif. – NASA’s Mars Curiosity rover has used its full array of instruments to analyze Martian soil for the first time, and found a complex chemistry within the Martian soil. Water and sulfur and chlorine-containing substances, among other ingredients, showed up in samples Curiosity’s arm delivered to an analytical laboratory inside the rover.

Detection of the substances during this early phase of the mission demonstrates the laboratory’s capability to analyze diverse soil and rock samples over the next two years. Scientists also have been verifying the capabilities of the rover’s instruments. (more…)

Read More

Hearty Organisms Discovered in Bitter-Cold Antarctic Brine

EAST LANSING, Mich. — Where there’s water there’s life – even in brine beneath 60 feet of Antarctic ice, in permanent darkness and subzero temperatures.

While Lake Vida, located in the northernmost of the McMurdo Dry Valleys of East Antarctica, will never be a vacation destination, it is home to some newly discovered hearty microbes. In the current issue of the Proceedings of the National Academy of Science, Nathaniel Ostrom, Michigan State University zoologist, has co-authored “Microbial Life at -13ºC in the Brine of an Ice-Sealed Antarctic Lake.” (more…)

Read More

Large Bacterial Population Colonized Land 2.75 Billion Years Ago

There is evidence that some microbial life had migrated from the Earth’s oceans to land by 2.75 billion years ago, though many scientists believe such land-based life was limited because the ozone layer that shields against ultraviolet radiation did not form until hundreds of millions years later.

But new research from the University of Washington suggests that early microbes might have been widespread on land, producing oxygen and weathering pyrite, an iron sulfide mineral, which released sulfur and molybdenum into the oceans. (more…)

Read More

Sediment Chemicals in Coastal Rivers Overall Lower in U.S. than Worldwide Averages

Almost all the sediment-associated chemical concentrations found in 131 of the nation’s rivers that drain to the Atlantic, Pacific and Gulf Coasts are lower than worldwide averages, according to a new study by the USGS. These coastal rivers are a significant pathway for the delivery of sediment-associated chemicals to the world’s coastal zones and oceans.

“I hope that the results of this new study will remind everyone that it is not only river water that can transport chemicals and pollutants, but also the associated sediment load,” said USGS Director Marcia McNutt. “Our citizens expect high environmental quality as compared with worldwide averages, but clean water alone will not suffice if river sediments are host to toxic heavy metals and concentrated organics that can produce dead zones.” (more…)

Read More

Disappearing and Reappearing Superconductivity Surprises Scientists

Washington, D.C. — Superconductivity is a rare physical state in which matter is able to conduct electricity—maintain a flow of electrons—without any resistance. This phenomenon can only be found in certain materials at low temperatures, or can be induced under chemical and high external pressure conditions. Research to create superconductors at higher temperatures has been ongoing for two decades with the promise of significant impact on electrical transmission. New work from a team including Carnegie’s Xiao-Jia Chen and Ho-kwang “Dave” Mao demonstrates unexpected superconductivity in a type of compounds called iron selenium chalcogenides. Their work is published online by Nature on February 22. (more…)

Read More