Taxonomy term

timothy oleson

Mass measured for smallest exoplanet yet

By the late 19th century, astronomers had calculated correctly that Mars — about half the diameter of Earth — holds roughly one-tenth the mass of Earth, whereas its density is about 71 percent that of our planet. These fundamental planetary traits have also long been known for Mercury and Venus. But measuring the masses and densities of the many roughly Earth-sized exoplanets discovered lately — which, to space telescopes, appear as mere specks as they pass in front of, or transit, their home stars — has proved challenging.

22 Mar 2016

The ups and downs of an island

In 1835, Captain Robert FitzRoy and the crew of the HMS Beagle — who were exploring and studying the Chilean coast with Charles Darwin in tow — arrived at Isla Santa Mariá near the city of Concepción six weeks after a magnitude-8.5 earthquake jolted the region. Along with scenes of dried seaweed and dead mussels lining the island’s shores well above the high-tide line, comparison of a bathymetric survey of a shallow bay adjacent to Santa Mariá to one conducted the previous year suggested to FitzRoy that the earthquake had thrust the island 2.4 to 3 meters out of the water.

18 Mar 2016

Red Planet Roundup: March 2016

With two rovers patrolling the surface of Mars, five spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

08 Mar 2016

Ice (Re)Cap: February 2016

From Antarctica to the Arctic; from polar caps, permafrost and glaciers to ocean-rafted sea ice; and from burly bears to cold-loving microbes, fascinating science is found in every nook and crevasse of Earth’s cryosphere, and new findings are announced often. Here are a few of the latest updates.
 
11 Feb 2016

Irrigation drives rain away in East Africa

Researchers have found that large-scale agricultural irrigation, intended to supplement precipitation, may actually drive rainfall away, potentially exacerbating conditions in some areas while improving them in nonirrigated lands. 
 
28 Jan 2016

Impact or eruptions: Are both to blame in the great end-Cretaceous whodunit?

Few episodes in geologic history are as widely recognized — and debated — as the end-Cretaceous extinction. For several decades, the Chicxulub impact has been the primary suspect. But new research suggests the impact wasn’t solely responsible for the extinctions; widespread volcanism in India seemed to play a role as well.

25 Jan 2016

Widespread malaria risk from African dams

Large dams cause more than 1 million cases of malaria annually in sub-Saharan Africa, according to the authors of a new study published in Malaria Journal.
 
17 Jan 2016

Red Planet Roundup: January 2016

With two rovers patrolling the surface of Mars, five spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.
 
14 Jan 2016

Lake sediments suggest mild volcanic winter after massive Toba eruption

Roughly 74,000 years ago, the largest volcanic eruption of at least the last 2.5 million years — and possibly the last 27 million years — spewed as much as 5,000 cubic kilometers of magma and ash, the latter of which spread far and wide from the source. This catastrophic eruption of the Toba supervolcano on the Indonesian island of Sumatra has long been suggested as a trigger for a precipitous period of global cooling known as a “volcanic winter” that in turn might have driven early humans to the brink of extinction. In a new study, researchers dispute these notions, concluding from an analysis of climate-sensitive microfossils preserved in lake sediments in East Africa — the ancestral home of early humans — that the region experienced little or no cooling following the massive eruption. 
 
10 Jan 2016

Meteorites might have created Earth’s earliest continents

Massive meteorite impacts on Earth are destructive events, gouging enormous craters in the crust and raining debris over the planet’s surface. But such huge impacts may have also created some of its earliest continental kernels, called cratons, during Archean times.
 
08 Jan 2016

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