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Dec 21, 2005 - NASA's Grace Earth observation satellite has created the first, comprehensive survey of the entire Greenland ice sheet. The spacecraft found that the volume of ice is decreasing by 162 cubic kilometres per year (39 cubic miles), which is higher than all previously published estimates. This ice melt is contributing 0.4 millimeters (.016 inches) per year to global sea level rise. Grace was also able to measure detailed changes in the surface of the sea floor after the Sumatran earthquake and resulting tsunami that happened almost a year ago.
Dec 11, 2005 - For more than 400 years, the Earth's magnetic North pole was in a roughly stable position, but now it's on the move, having drifted nearly 1,100 km (680 miles) in the last century. At this rate, it'll move out of Canada, and into Siberia in the next 50 years. If that happens, Alaska and Northern Canada may lose the beautiful Northern Lights, which are caused by the interaction of the magnetic pole and the solar wind. It could be that this is a normal oscillation of the magnetic pole, or it might be that the Earth's magnetic poles are getting ready to flip.
Dec 7, 2005 - The ozone hole that developed above Antarctica looks smaller this year than previous years, based on observations from NASA's Aura satellite. The largest hole was measured in 1998; almost triple the size of 1985's hole. The temperature of the atmosphere above Antarctica seems to be one of the biggest factors deciding the size of the ozone hole - the colder it gets, the more ozone that's destroyed.
Dec 5, 2005 - Scientists from NASA and the National Science Foundation have created a new way to view the Earth's atmosphere during space storms. These large-scale storms resemble weather cold fronts that result from plumes of electrified plasma that flash across the Earth's ionosphere. These plumes used to seem like random events, but scientists have gotten pretty good at predicting them now, using a fleet of spacecraft. For the first time, they can now directly connect plasma observed in the atmosphere with these plumes that can extend thousands of kilometres into space.
Dec 5, 2005 - The rise of complex life on Earth matches the appearance of oxygen in the atmosphere, and new evidence from University of Maryland scientists suggests that the increase was more gradual than previously believed. According to microbial evidence, oxygen first appeared in our atmosphere 2.4 billion years ago, and a second large increase started 1.3 billion years ago, and reached its current levels about 600 million years ago.
Nov 25, 2005 - Now on its way to our nearest planetary neighbour, Venus Express tested its VIRTIS optics system by taking pictures of the Earth and the Moon. ESA controllers ran the spacecraft through a commissioning phase to test all of its scientific instruments. It took pictures of the Earth and the Moon when it was 3.5 million kilometres away. The VIRTIS instrument is also on board the Rosetta spacecraft, which also took images of our planet. ESA scientists will be able to compare the images to ensure the instrument is working perfectly.
Nov 23, 2005 - Researchers from the University of Colorado at Boulder think they've found evidence that the very early Earth had continents soon after the planet formed, overturning theories that the planet was Moon-like, or covered with oceans. The team analyzed a rare element called hafnium in ancient minerals from the Jack Hills in Western Australia. It showed that continental crusts had formed 4.4 - 4.5 billion years ago, and were then recycled into the Earth's mantle.
Nov 18, 2005 - Most geologists believe that the early history of our planet was an extreme, "hellish" environment, under constant bombardment from asteroids, and completely devoid of modern formations, like continents. Researchers from ANU disagree, and think they've found evidence that continents had already formed within the first 500 million years, and there was liquid water interacting with rocks. The Earth at that time might have looked remarkably similar to our current planet, complete with continents and oceans.
Nov 7, 2005 - After 5 years afloat, the gigantic B-15A iceberg has broken up off the coast of Antarctica's Cape Adare. This image of the iceberg was taken using ESA's Envisat satellite Advanced Synthetic Aperture Radar (ASAR). The bottle-shaped iceberg had run aground, and probably flexed and strained until it broke up into 9 pieces along fault lines on October 27. The largest pieces have been named B-15M, B-15N and B-15P.
Nov 4, 2005 - After gathering data on Greenland for more than a decade, ESA scientists have reported that the island's ice sheet is actually growing at its interior. Data collection began in 1991 with the radar altimeter instrument on board ESA's ERS-1, followed by ERS-2, and most recently Envisat, which has 10 instruments to measure various properties of the Earth from orbit. Greenland's ice sheet seems to be thickening at a rate of 6.4 cm (2.6 inches) a year above altitudes of 1,500 metres (5000 feet). Below that altitude, the ice sheets are decreasing in thickness.
Oct 19, 2005 - Just a few days ago, Wilma was a tropical storm, but now it has exploded into a Category 5 hurricane - with the lowest pressure ever recorded in an Atlantic storm. Wilma's pressure was measured early Wednesday at just 882 millibars, breaking the previous record of 888 set in 1988 by Hurricane Gilbert. Wilma is currently off the coast Mexico's Yucatan peninsula , but it's expected to take a sharp right turn and move up through the Florida panhandle on Saturday.
Oct 4, 2005 - Australian researchers are using ESA's Envisat Earth Observation Satellite to peer down and help judge the health of the Great Barrier Reef. Envisat's MERIS sensor can detect coral bleaching down to 10 metres below the surface of the water. This bleaching occurs when the symbiotic algae living with the coral are expelled when ocean temperatures rise. Since Envisat images the entire planet every three days, scientists will be able to watch this bleaching process on a weekly basis to see how the reefs are doing.
Sep 29, 2005 - With the "Snowball Earth" hypothesis, scientists have proposed that our planet was once encased under a thick layer of ice and snow. Life could only survive huddled around hot vents deep under water. But now scientists have found fossil evidence of creatures that lived during this period, but were photosynthesizing. This means they needed to live under thin enough ice for sunlight to get through. It's possible that the entire planet wasn't encased in ice, instead there were large patches of thin ice, or even open water near the equator.
Sep 23, 2005 - The European Space Agency's Envisat satellite took this photo of Hurricane Rita on September 22, 2005 as it was passing Southern Florida. Envisat can use its radar instruments to peer through a hurricane's clouds and measure the roughness of the ocean beneath it. This is how scientists can estimate the wind speed of the storm at various points. Rita is expected to slam into Texas or Louisiana early Saturday morning.
Sep 19, 2005 - Researchers from Open University have uncovered that the Earth suffered a sudden, severe period of global warming approximately 180 million years ago. During this period, vast quantities of methane gas were released in three huge pulses when underwater stores of gas hydrate melted. This greenhouse gas warmed the Earth by 10 degrees C and resulted in the extinction of many species on land and in the oceans.
Sep 16, 2005 - NASA has two new Earth Observation satellites in the final stages of preparation before their launch: CloudSat and Calipso. The two satellites will be launched together by a Boeing Delta II rocket from Vandenberg Air Force Base in California. They will be launched into a polar orbit, and maintain a close formation. CloudSat has an extremely powerful cloud-profiling radar, which can distinguish between cloud particles and precipitation. Calipso will be able to detect aerosol particles in the air, and can tell the difference between these particles and clouds to measure the amount of air pollution. They may launch as soon as October 26.
Sep 14, 2005 - Researchers at Washington University in St. Louis have used primitive meteorites called chondrites to develop a model of the Earth's early atmosphere. And it looked nothing like what we have today. Instead of the familiar oxygen and nitrogen, our early atmosphere would have been a toxic mixture of methane, ammonia, hydrogen and water vapour. Simulating this early environment was actually quite difficult to calculate because the minerals of the early Earth reacted to the hot environment in hard-to-predict ways.
Aug 30, 2005 - The ozone hole above the South Pole has returned, and it's on track to be one of the biggest on record. At this time, the hole is the size of Europe, but it will probably continue growing during September - bigger holes appeared in 1996 and 2000. The size of the ozone hole and the time of its appearance depends on the weather conditions in the southern hemisphere.
Aug 29, 2005 - According to new research from geologists, the Earth's core rotates just a little bit faster - about 1 degree per year - than the crust of the planet. The scientists took advantage of historical records for "earthquake twins" near the South Sandwich Islands. These are quakes that occurred in virtually the same spot with the same magnitude, but were years apart. As the seismic waves passed through the Earth, they were bent as they passed through the Earth's iron core. The shape of this bending has changed over time, indicating the core's faster rotation.
Aug 25, 2005 - Around 251 million years ago, something happened to the Earth's climate that wiped out 90-95% of marine life and 70% of terrestrial life. Scientists at the National Center for Atmospheric Research (NCAR) have developed a computer model that demonstrates that rapid increases in carbon dioxide belched out of volcanoes did the trick. Temperatures were 10 to 30 degrees Celsius (18 to 54 degrees Fahrenheit) higher than they are today, which broke a cycle that pulled carbon dioxide out of the atmosphere.
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