Tag Archives: earth

Research in the news: The rise of oxygen on Earth

Yale’s Noah J. Planavsky and collaborators have published a Nature review article titled “The rise of oxygen in Earth’s early ocean and atmosphere.”

Published online Feb. 19, the review surveys and assesses research about the emergence of significant oxygen concentrations and suggests that this happened hundreds of millions of years before the “great oxygenation event” of 2.3 billion years ago. In between, oxygen levels appear to have fluctuated considerably, according to the authors. (more…)

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Yale study: Forest emissions, wildfires explain why ancient Earth was so hot

The release of volatile organic compounds from Earth’s forests and smoke from wildfires 3 million years ago had a far greater impact on global warming than ancient atmospheric levels of carbon dioxide, a new Yale study finds.

The research provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change and the relevance of natural components, according to the authors. They do not address or dispute the significant role in climate change of human-generated CO2 emissions. (more…)

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Kepler Finds a Very Wobbly Planet

Imagine living on a planet with seasons so erratic you would hardly know whether to wear Bermuda shorts or a heavy overcoat. That is the situation on a weird, wobbly world found by NASA’s planet-hunting Kepler space telescope.

The planet, designated Kepler-413b, precesses, or wobbles, wildly on its spin axis, much like a child’s top. The tilt of the planet’s spin axis can vary by as much as 30 degrees over 11 years, leading to rapid and erratic changes in seasons. In contrast, Earth’s rotational precession is 23.5 degrees over 26,000 years. Researchers are amazed that this far-off planet is precessing on a human timescale. (more…)

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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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