The largest moon in our solar system, a companion to Jupiter named Ganymede, might have ice and oceans stacked up in several layers like a club sandwich, according to new NASA-funded research that models the moon’s makeup.
Previously, the moon was thought to harbor a thick ocean sandwiched between just two layers of ice, one on top and one on bottom. (more…)
Massive terrestrial planets, called “super-Earths,” are known to be common in Earth’s galaxy, the Milky Way. Now a Northwestern University astrophysicist and a University of Chicago geophysicist report the odds of these planets having an Earth-like climate are much greater than previously thought.
Nicolas B. Cowan and Dorian Abbot’s new model challenges the conventional wisdom, which says super-Earths actually would be very unlike Earth—each would be a waterworld, with its surface completely covered in water. They conclude that most tectonically active super-Earths—regardless of mass—store most of their water in the mantle and will have both oceans and exposed continents, enabling a stable climate such as Earth’s. (more…)
ANN ARBOR — Mass extinctions, like lotteries, result in a multitude of losers and a few lucky winners. This is the story of one of the winners, a small, shell-crushing predatory fish called Fouldenia, which first appears in the fossil record a mere 11 million years after an extinction that wiped out more than 90 percent of the planet’s vertebrate species.
The extinction that ended the Devonian Era 359 million years ago created opportunities quickly exploited by a formerly rare and unremarkable group of fish that went on to become—in terms of the sheer number of species—the most successful vertebrates (backboned animals) on the planet today: the ray-finned fish. (more…)
Genomic techniques facilitate discovery that gene expression causes disparity
Although they live in similarly extreme ecosystems at opposite ends of the world, Antarctic insects appear to employ entirely different methods at the genetic level to cope with extremely dry conditions than their counterparts that live north of the Arctic Circle, according to National Science Foundation- (NSF) funded researchers.
Writing in the Proceedings of the National Academy of Sciences, the researchers concluded, “Polar arthropods have developed distinct… mechanisms to cope with similar desiccating conditions.” (more…)
Researchers led by Matt Sullivan at the UA are among the first to dive into the world of viruses drifting through the world’s oceans.
Surrounded by the deep blue of the Pacific Ocean stretching from horizon to horizon, a lonely dot is glinting in the sun. It is the aluminum hull of a sailboat, a 118-foot schooner with white sails billowing from two masts.
On the deck, crewmembers and scientists are milling about. Commands are flying back and forth, and soon a strange contraption consisting of tubes clustered around an array of sensors dangling from a crane is lowered into the water, until it disappears in the clear blue depths. (more…)
*Evidence of water mass moving south 70 million years ago shows how warmth was distributed*
COLUMBIA, Mo. – New research from the University of Missouri indicates that Atlantic Ocean temperatures during the greenhouse climate of the Late Cretaceous Epoch were influenced by circulation in the deep ocean. These changes in circulation patterns 70 million years ago could help scientists understand the consequences of modern increases in greenhouse gases.
“We are examining ocean conditions from several past greenhouse climate intervals so that we can understand better the interactions among the atmosphere, the oceans, the biosphere, and climate,” said Kenneth MacLeod, professor of geological sciences in the College of Arts and Science. “The Late Cretaceous Epoch is a textbook example of a greenhouse climate on earth, and we have evidence that a northern water mass expanded southwards while the climate was cooling. At the same time, a warm, salty water mass that had been present throughout the greenhouse interval disappeared from the tropical Atlantic.” (more…)
*New results indicate potential to reduce certain greenhouse gas emissions from oceans to atmosphere*
Increasing acidity in the sea’s waters may fundamentally change how nitrogen is cycled in them, say marine scientists who published their findings in this week’s issue of the journal Proceedings of the National Academy of Sciences (PNAS).
Nitrogen is one of the most important nutrients in the oceans. All organisms, from tiny microbes to blue whales, use nitrogen to make proteins and other important compounds. (more…)
Geologist Noah Plavansky examines rocks deposited after a "Snowball Earth" glacial event. Image credit: Lyons Lab, UC-Riverside
*Spike in ancient marine phosphorus concentrations linked to emergence of complex life*
Biogeochemists have found new evidence linking “Snowball Earth” glacial events to the rise of early animals. The research was funded by the National Science Foundation (NSF).
Study results appear in this week’s issue of the journal Nature.
The controversial Snowball Earth hypothesis posits that, on several occasions, the Earth was covered from pole to pole by a thick sheet of ice lasting for millions of years.
These glaciations, the most severe in Earth history, occurred from 750 to 580 million years ago. (more…)
