Scientists have found evidence that the Earth might have flipped over in the past, completely shifting the orientation of its poles. The theory has been around for years; that a large mountain range or supervolcano might unbalance the spinning Earth. Over the course of millions of years, the Earth would change the orientation of its axis until the object was balanced at the equator again. The scientists found evidence of magnetic grains in layers of rock sediment on the ocean floor that maintain a record of the Earth’s magnetic field over millions of years.
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The Secret to Earth’s Shining Auroras
Auroras appear near to the poles when material from the Sun interacts with the Earth’s magnetic field. Now ESA’s Cluster spacecraft have helped determine exactly how energetic particles are generated that cause the atmosphere to glow so brightly. Cluster has confirmed that the interactions with the Earth’s magnetosphere cause flows of gas traveling more than 300 km/second (186 miles/second) to crash into the atmosphere, generating the light show we see.
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Satellites Measure Melting Greenland Ice
NASA’s GRACE satellites have measured an increasing rate of ice melt in Greenland. According to new analysis by researchers at the University of Arizona at Austin, the loss of ice from Greenland’s southeastern region has sped up between 2002 and 2005. Approximately 239 cubic kilometers (57 cubic miles) is now lost each year. Greenland contains 10% of the Earth’s fresh water, and this melting ice is contributing 0.56 mm (.02 inches) to globally rising sea levels.
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Cluster Spacecraft Catch a Magnetic Reconnection
ESA’s Cluster spacecraft were in the right place at the right time on September 15, 2001. They flew through a region of the Earth’s magnetosphere at the exact moment that it reconfigured itself. The wealth of data will help scientists better model interactions between the Earth’s magnetosphere and the solar wind, as well as the magnetic fields around other stars and exotic objects with powerful magnetic fields.
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MetOp Prepares for Launch
In about a week, ESA’s MetOp-A satellite will be launched from the Baikonur Cosmodrome in Kazakhstan. If all goes well, the meteorological satellite will be placed on July 17 by a Russian Soyuz rocket into a low Earth polar orbit. MetOp-A carries 11 scientific instruments designed to scan the Earth’s atmosphere, land and oceans. There will eventually be three similar MetOp satellites flying in roughly the same orbit at an altitude of 817km (507 miles) collecting high resolution data from the Earth.
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Ozone Recovery is Going Slowly
Although the Earth’s ozone layer is on the mend, the recovery is going more slowly than expected. Scientists have developed a new computer model that takes existing atmospheric data and correctly reproduces the size and shape of the ozone hole above Antarctica for the past 27 years. The model then predicts into the future, forecasting that the ozone hole will stick around until 2068, and not 2050 as scientists originally believed.
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GPS Can Predict Tsunamis
After the terrible tsunami damage caused by the Sumatra earthquake in December 2004, scientists have been searching for strategies to predict future killer waves. A team of university scientists have shown that Global Positioning System software developed at NASA can determine within minutes if an earthquake is strong enough to generate an ocean-wide tsunami. Ground stations within a few thousand kilometres of the earthquake can actually measure their displacement using the GPS satellites. If they’ve moved enough, there’s a high risk of a tsunami.
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Fizzing Space Around the Earth
New observations from ESA’s Cluster and Double Star spacecraft have found that that space around the Earth fizzes as bubbles of superheated gas are created and popped. These bubbles are known as density holes, and they occur when gas in a region drops in density, but rises in temperature. The European spacecraft encountered these bubbles on the day-lit side of Earth at an altitude of 13-19 Earth radii. Scientists aren’t exactly sure what’s causing these bubbles, but it has something to do with the interaction between the Earth’s magnetic field and the solar wind.
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CALIPSO Begins Scientific Observations
NASA’s newly launched CALIPSO Earth observation satellite began its scientific observations last week. The satellite is designed to help scientists understand what effect cloud reflectivity and aerosol particles are having on the planet’s climate. CALIPSO is part of a satellite formation called the A-Train; several satellites in the same orbit which can analyze the same spot on Earth, one after the other.
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First Images From Cloudsat
Meteorologists and scientists have a new tool at their disposal; NASA’s new CloudSat satellite, which is capable of building 3-D images of clouds. CloudSat launched on April 28 from Vandenberg Air Force Base with two other satellites. After several weeks of testing, mission managers tested its Cloud-Profiling Radar system in May. Its first image was a slice of atmosphere above the North Sea in the Atlantic Ocean. CloudSat’s radar system is 1,000 times more powerful than typical weather radar.
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