Taxonomy term

timothy oleson

MESSENGER mission ends with a bang, and more data

After 11 years in space and more than 4,100 laps around Mercury since entering orbit in 2011, NASA’s MESSENGER spacecraft was decommissioned in heroic fashion on April 30, slamming into the planet’s surface at more 14,000 kilometers per hour after it had run out of propellant. Fittingly, it gouged a 16-meter-wide crater of its own amid the myriad others it observed there.
 
12 Sep 2015

Fate of atolls not necessarily tied to sea-level rise

The western Pacific Ocean is home to many atolls: rings of low-lying islands built from calcite sands and the erosional remnants of coral reefs. This region is also home to some of the highest rates of sea-level rise in recent decades — an unsettling fact for the atolls’ inhabitants and others worried that rising waters will eat away at the islands and evict residents for good. But according to a new study documenting long-term change at one Pacific atoll, the future for such islands might not be so bleak.

30 Aug 2015

Map shows where lightning zaps most

Lightning strikes far more often over land than sea and is more concentrated closer to the equator — both testaments to the greater atmospheric instability over those parts of the planet.

29 Aug 2015

Seismometers listen for falling rocks

Scores of natural rockfalls occur in California’s Yosemi­­te Valley every year, often with little or no advance warning, posing hazards to people and infrastructure. In 1980, for example, a fall near Yosemite Falls killed three people and injured 19. Efforts to record and document rockfalls are rudimentary, relying only on eyewitness accounts and after-the-fact observations of fresh talus piles, which means many events are likely going unreported. In a new study, however, researchers interested in whether there’s a better way to monitor these events propose that seismic and infrasound sensors can help keep tabs on the granite slabs dropping from Yosemite’s cliffs.
 
25 Aug 2015

Earth-like atmosphere enough to set some exoplanets spinning

Earth is “Exhibit A” in showing that planetary rotation — which moderates global climate, keeps a lot of water in liquid form and generally makes the place more livable — is a plus when it comes to sustaining life. But scientists have thought that many of the rocky, Earth-like exoplanets discovered recently, which might otherwise be considered potentially hospitable to life, aren’t so fortunate. On these unlucky worlds, unable to rotate because they’re held too tightly by their parent stars’ gravity, one half of the planet is perpetually roasted by stellar radiation while the other is left frigid and dark. Now, however, a new study suggests that a little atmosphere can go a long way toward helping exoplanets rotate.
 

22 Aug 2015

Ice (Re) Cap: August 2015

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.
 
15 Aug 2015

Red Planet Roundup: July 2015

With two rovers patrolling the surface of Mars, five spacecraft in orbit 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.
 
15 Jul 2015

Bare Earth Elements: "Volcano of Fire" eruption forces evacuations in Mexico

Mexico’s civil protection agency, along with local officials, issued an emergency declaration Saturday for the area surrounding Colima Volcano, after the eruption that began on Thursday intensified into the weekend. The eruption is said to have sent towering clouds of ash upwards of 4 kilometers into the sky, while lava and pyroclastic flows have spewed down the flanks of the volcano also known as Volcán de Fuego, or Volcano of Fire — one of Mexico’s most active.

13 Jul 2015

Sediment load shapes rivers

The amount of sediment carried in meandering rivers influences how quickly the bends in those rivers migrate back and forth, according to recent research in Nature Geoscience addressing a longstanding question regarding river evolution. Meanders form when flowing water erodes one riverbank while simultaneously depositing sediment on the opposite bank, gradually creating more and more pronounced U-shaped bends. Sometimes, the rivers cut new channels across the narrow necks of such bends, isolating the abandoned meanders to form distinctive oxbow lakes. 
 
04 Jul 2015

Ice (Re) Cap: June 2015

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.
 
14 Jun 2015

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