Tag Archives: earth

Eight Seconds of Terror

A JPL Scientist Reflects on L.A.’s Last Big Quake

Twenty years ago this week, in the predawn darkness of Jan. 17, 1994, at five seconds before 4:31 a.m. PST, the ground ruptured violently on a blind thrust fault (a crack in Earth’s crust that does not reach the surface) about 11 miles (18 kilometers) beneath Reseda, in California’s San Fernando Valley about 20 miles (31 kilometers) northwest of downtown Los Angeles. The resulting magnitude 6.7 earthquake, known as the Northridge earthquake, became the first large quake to strike directly under an urban area in the United States since the 1933 magnitude 6.4 earthquake in Long Beach, Calif. (more…)

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Exoplanet study finds ‘super-Earths’ likely have oceans and continents

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…)

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Stormy Stars? NASA’s Spitzer Probes Weather on Brown Dwarfs

Swirling, stormy clouds may be ever-present on cool celestial orbs called brown dwarfs. New observations from NASA’s Spitzer Space Telescope suggest that most brown dwarfs are roiling with one or more planet-size storms akin to Jupiter’s “Great Red Spot.”

“As the brown dwarfs spin on their axis, the alternation of what we think are cloud-free and cloudy regions produces a periodic brightness variation that we can observe,” said Stanimir Metchev of the University of Western Ontario, Canada. “These are signs of patchiness in the cloud cover.” (more…)

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NASA’s Kepler Provides Insights on Enigmatic Planets

More than three-quarters of the planet candidates discovered by NASA’s Kepler spacecraft have sizes ranging from that of Earth to that of Neptune, which is nearly four times as big as Earth. Such planets dominate the galactic census but are not represented in our own solar system. Astronomers don’t know how they form or if they are made of rock, water or gas.

The Kepler team today reports on four years of ground-based follow-up observations targeting Kepler’s exoplanet systems at the American Astronomical Society meeting in Washington. These observations confirm the numerous Kepler discoveries are indeed planets and yield mass measurements of these enigmatic worlds that vary between Earth and Neptune in size. (more…)

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Decade-Old Rover Adventure Continues on Mars and Earth

Eighth graders didn’t have Facebook or Twitter to share news back then, in January 2004. Bekah Sosland, 14 at the time, learned about a NASA rover landing on Mars when the bouncing-ball video on the next morning’s Channel One news in her Fredericksburg, Texas, classroom caught her eye.

“I wasn’t particularly interested in space at the time,” she recalled last week inside the spacecraft operations facility where she now works at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “I remember I was talking with friends, and out of the corner of my eye I noticed this thing bouncing and rolling on a red surface. I watched as it stopped and opened up, and it had this rover inside.” (more…)

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UChicago researchers use Hubble Telescope to reveal cloudy weather on alien world

Weather forecasters on exoplanet GJ 1214b would have an easy job. Today’s forecast: cloudy. Tomorrow: overcast. Extended outlook: more clouds.

That’s the implication of a study led by researchers in the Department of Astronomy and Astrophysics at the University of Chicago who have definitively characterized the atmosphere of a super-Earth class planet orbiting another star for the first time. (more…)

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Scientists solve a decades-old mystery in the Earth’s upper atmosphere

New research published in the journal Nature resolves decades of scientific controversy over the origin of the extremely energetic particles known as ultra-relativistic electrons in the Earth’s near-space environment and is likely to influence our understanding of planetary magnetospheres throughout the universe.

Discovering the processes that control the formation and ultimate loss of these electrons in the Van Allen radiation belts — the rings of highly charged particles that encircle the Earth at a range of about 1,000 to 50,000 kilometers above the planet’s surface — is a primary science objective of the recently launched NASA Van Allen Probes mission. Understanding these mechanisms has important practical applications, because the enormous amounts of radiation trapped within the belts can pose a significant hazard to satellites and spacecraft, as well astronauts performing activities outside a craft. (more…)

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Hard rock life

Scientists are digging deep into the Earth’s surface collecting census data on the microbial denizens of the hardened rocks. What they’re finding is that, even miles deep and halfway across the globe, many of these communities are somehow quite similar.

The results, which were presented at the American Geophysical Union conference Dec. 8, suggest that these communities may be connected, said Matthew Schrenk, Michigan State University geomicrobiologist. (more…)

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