
To find more information about tornado images on the Earth Observatory website, refer to the Earth Observatory article in NEON.
Link to the NES Virtual Campus home page.
To find more information about tornado images on the Earth Observatory website, refer to the Earth Observatory article in NEON.
Link to the NES Virtual Campus home page.
Link to the NES Virtual Campus home page.
The March 11, magnitude 9.0 earthquake in Japan may have shortened the length of each Earth day and shifted its axis. But don’t worry—you won’t notice the difference.
Using a United States Geological Survey estimate for how the fault responsible for the earthquake slipped, research scientist Richard Gross of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., applied a complex model to perform a preliminary theoretical calculation of how the Japan earthquake—the fifth largest since 1900—affected Earth’s rotation. His calculations indicate that by changing the distribution of Earth’s mass, the Japanese earthquake should have caused Earth to rotate a bit faster, shortening the length of the day by about 1.8 microseconds (a microsecond is one millionth of a second).
The calculations also show the Japan quake should have shifted the position of Earth’s figure axis (the axis about which Earth’s mass is balanced) by about 17 centimeters (6.5 inches), towards 133 degrees east longitude. Earth’s figure axis should not be confused with its north-south axis; they are offset by about 10 meters (about 33 feet). This shift in Earth’s figure axis will cause Earth to wobble a bit differently as it rotates, but it will not cause a shift of Earth’s axis in space—only external forces such as the gravitational attraction of the sun, moon and planets can do that.
Link to the NES Virtual Campus home page.
Link to the NES Virtual Campus home page.
On Feb. 14, 2011, NASA’s Stardust-NExT (New Exploration of Tempel 1) mission will encounter Comet Tempel 1, providing a unique opportunity to measure the dust properties of two separate comets (Wild 2 and Tempel 1) with the same instrument for accurate data comparison. The encounter also will provide a comparison between two observations of a single comet, Tempel 1, taken before and after a single orbital pass around the sun.
On Jan. 21st, NanoSail-D unfurled a 10 m2 sail 650 km above Earth’s surface, becoming the first solar sail to orbit our planet. For the next few months it will skim the top of the atmosphere, slowly descending in a test of ‘drag sails’ as a means of de-orbiting space junk. If all goes as planned, the spacecraft will disintegrate like a meteor in April or May of 2011, dispersing harmlessly more than 1100 km high.
Meanwhile, sky watchers should be alert for flares lasting 5 to 10 seconds outshining the brightest stars in the sky, mimicking a supernova, perhaps even casting faint shadows at your feet.
For more information about NanoSail-D click here.
(Full article located at Science@NASA, by Dr. Tony Phillips)