Showing posts with label NASA. Show all posts
Showing posts with label NASA. Show all posts
Monday, September 19, 2011
RussiaToday Reports on Comet Elenin
The ancient Mayan calendar predicts that we will be coming to an end of a cycle in the year 2012. The winter solstice is believed to be the date that the world will end. Lately there has been a lot of buzz about the comet Elenin. The comet is set to come close to earth on October 16th of this year and many believe this will have atrocious affects on the planet
Tuesday, March 15, 2011
Japan Quake May Have Shortened Earth Days, Moved Axis
Wikipedia 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.
Both calculations will likely change as data on the quake are further refined.
In comparison, following last year's magnitude 8.8 earthquake in Chile, Gross estimated the Chile quake should have shortened the length of day by about 1.26 microseconds and shifted Earth's figure axis by about 8 centimeters (3 inches). A similar calculation performed after the 2004 magnitude 9.1 Sumatran earthquake revealed it should have shortened the length of day by 6.8 microseconds and shifted Earth's figure axis by about 7 centimeters, or 2.76 inches. How an individual earthquake affects Earth's rotation depends on its size (magnitude), location and the details of how the fault slipped.
Gross said that, in theory, anything that redistributes Earth's mass will change Earth's rotation.
"Earth's rotation changes all the time as a result of not only earthquakes, but also the much larger effects of changes in atmospheric winds and oceanic currents," he said. "Over the course of a year, the length of the day increases and decreases by about a millisecond, or about 550 times larger than the change caused by the Japanese earthquake. The position of Earth's figure axis also changes all the time, by about 1 meter (3.3 feet) over the course of a year, or about six times more than the change that should have been caused by the Japan quake."
Source:nasa
Monday, March 14, 2011
Biggest Full Moon Possible 19 March 2011
WikipediaGet ready for a close encounter with the moon. On March 19, the moon won't just be at its closest approach to Earth in its elliptical orbit, but enthusiasts say it will be closer to Earth than it's been in 18 years. The moon's orbit around us is slightly elliptical, and when the moon is at the near point it is known as a lunar perigee. But on the Internet, astronomy and astrology fans are calling this upcoming lunar event a "supermoon."For the past few days, they've not only been buzzing about the mega moon, but the meteorological mayhem they expect it to cause. But no need to grab your survival kit just yet -- scientists say it just isn't so.
In a blog post earlier this month, AccuWeather blogger Mark Paquette said a new or full moon at 90 percent or more of its closest perigee qualifies as a "supermoon." Next weekend's full moon won't just be a supermoon but an extreme supermoon, he said, because the moon will be almost precisely at its closest distance to Earth.
According to "new age" forecasts, he said, the supermoon is expected to bring strong earthquakes, storms or unusual climate patterns.
"There were supermoons in 1955, 1974, 1992 and 2005. These years had their share of extreme weather and other natural events. Is the Super Moon and these natural occurrences a coincidence?" he wrote. "Some would say yes; some would say no. I'm not here to pick sides and say I'm a believer or non-believer in subjects like this, but as a scientist I know enough to ask questions and try to find answers."
Paquette told ABCNews that he wants to remain "neutral" on the topic but said, "I do think it's possible that it could bring earthquakes, volcanic eruptions or anything weather-related as well."
But NASA astronomer Dave Williams said there's no reason to believe that anything out of the ordinary -- aside from an especially big and bright full moon -- will take place next week.
"There's nothing really special about this," he said.
For starters, although the moon will be closer than it's been for 18 or 19 years, it will only be one or two percent closer.
"It's nothing you could notice unless you made really accurate measurements," he said. "It's a few thousand miles closer, but as far as the moon's orbit is considered, that's nothing."
Comstock/Thinkstock(NEW YORK) -- Copyright 2011 ABC News Radio
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