Earthquakes And Asteroids - November 2011

The bulls-eye shows epicenter of the 5.6 magnitude Oklahoma earthquake, which took place at 10:53 p.m. CST, November 5, 2011.  Click on image to enlarge.

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Shake, Rattle and Roll!
by Sunny Williams, Lights in the Texas Sky

Near Earth misses by asteroids and Earthquakes, where and when you don't expect them to be.  It's almost too much excitement!

It was a couple of minutes before 11:00 p.m. Saturday night, November 5, 2011, when I was rudely shaken from bed.

I had gone to bed early but my spouse (Joe) was up watching TV, when suddenly the bed started bouncing and shaking like one of those vibrating motel beds.  I could even hear the thumping of the bed legs on the floor.  So could Joe and as soon as he heard my exclamations of surprise, he came running to see if I was alright.

Come to find out, his recliner had also been doing the Watusi, along with the ceiling fans and anything else not nailed down.

Well after that rude arousal I certainly couldn't sleep, so I got up and checked Google News.  Sure enough, a 5.6 magnitude earthquake had hit Oklahoma, the epicenter located near Sparks, 44 miles northeast of Oklahoma City, at a depth of 3.1 miles.

By now you all know I live near the town of Breckenridge, Texas.  That is just a bit over 200 miles SW from OKC but I've read that the Oklahoma tremblor was felt up to 300 miles away.  That's some major shaking.

There was only one other time that I felt the earth shake this bad; that was when we were stationed at Fort Lewis, Washington, back in 1974-75.  I believe an earthquake shook the Oregon coast, which reverberated up into Washington state.

The Oregon tremble was my first experience with quakes but we actually had dishes and window panes rattle during a shake in South Texas, back in the late 80s.  It was centered somewhere east of Waco but didn't amount to much.

Now I don't know about you but for a born and raised Texan, experiencing an earthquake is unnerving, to say the least.  I've lived through tornadoes and even a hurricane but to have the ground beneath me let me down, now that's a bum deal right there.

What's next, an asteroid?

More news on the Oklahoma earthquake:
http://www.cnn.com/2011/11/06/us/oklahoma-earthquake/?hpt=us_c2
http://www.cbsnews.com/8301-201_162-57319310/5.6-mag-okla-quakes-rattle-nerves/

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Prepare to duck!  Another asteroid headed our way.
by Sunny Williams, Lights in the Texas Sky


Due on Tuesday, November 8, 2011 at 6:28 p.m.EST, an asteroid dubbed 2005 YU55 will come within 202,000 miles of Earth, before racing back out into space. That is about 38,000 miles closer to us than our own moon.

Carbon-colored and dark, the asteroid measures some 1,300 feet wide. It will be the closest visit by a space rock this size in more than three decades.

"This is not a potentially hazardous asteroid, just a good opportunity to study one," National Science Foundation astronomer Thomas Statler says. NASA and the NSF plan a series of radar telescope and other observations starting Friday, aimed at mapping the asteroid's surface and chemistry.

"The radar measurements should be pretty spectacular," Statler says.

At a quarter of a mile across, an asteroid this size landing in Earth's ocean would trigger a magnitude-7.0 earthquake and 70-foot-high tsunami waves some 60 miles away, according to Jay Melosh of Purdue University in Indiana. Such impacts are thought to come about once every 100,000 years.

“We’re extremely confident, 100 percent confident, that this is not a threat,” said the manager of NASA’s Near Earth Object Program, Don Yeomans. “But it is an opportunity.”

Lucky us, asteroid 2005 YU55 will be back in 2028.

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In April 2010, this radar image of the near-Earth asteroid 2005 YU55 was taken by the Arecibo radio telescope in Puerto Rico. On Nov. 8, 2011, this large space rock zips by Earth again and will be surveyed by radar, visual and infrared equipment.
CREDIT: Space.com/NASA/Cornell/Arecibo

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Huge asteroid headed for close encounter with Earth

(Reuters) - A huge asteroid will pass closer to Earth than the moon Tuesday, giving scientists a rare chance for study without having to go through the time and expense of launching a probe, officials said.

Earth's close encounter with Asteroid 2005 YU 55 will occur at 6:28 p.m. EST (2328 GMT) Tuesday, as the space rock sails about 201,000 miles from the planet.

"It is the first time since 1976 that an object of this size has passed this closely to the Earth. It gives us a great -- and rare -- chance to study a near-Earth object like this," astronomer Scott Fisher, a program director with the National Science Foundation, said Thursday during a Web chat with reporters.

The orbit and position of the asteroid, which is about 1,312 feet in diameter, is well known, added senior research scientist Don Yeomans, with NASA's Jet Propulsion Laboratory in Pasadena, California.

"There is no chance that this object will collide with the Earth or moon," Yeomans said.

Thousands of amateur and professional astronomers are expected to track YU 55's approach, which will be visible from the planet's northern hemisphere. It will be too dim to be seen with the naked eye, however, and it will be moving too fast for viewing by the Hubble Space Telescope.

"The best time to observe it would be in the early evening on November 8 from the East Coast of the United States," Yeomans said. "It is going to be very faint, even at its closest approach. You will need a decent-sized telescope to be able to actually see the object as it flies by."

Scientists suspect YU 55 has been visiting Earth for thousands of years, but because gravitational tugs from the planets occasionally tweak its path, they cannot tell for sure how long the asteroid has been in its present orbit.

"These sorts of events have been happening for most of the lifetime of the Earth, about 4.5 billion years," Fisher said.

Computer models showing the asteroid's path for the next 100 years show there is no chance it will hit Earth during that time, added Yeomans.

"We do not think that it will ever impact the Earth or moon (but) we only have its orbit calculated for the next 100 years," he said.

Previous studies show the asteroid, which is blacker than charcoal, is what is called a C-type asteroid that is likely made of carbon-based materials and some silicate rock.

More information about its composition and structure are expected from radar images and chemical studies of its light as the asteroid passes by the planet.

"I've read that we will be able to see details down to a size of about 15 feet across on the surface of the asteroid," Fisher said.

NASA is working on a mission to return soil samples from an asteroid known as 1999 RQ36 in 2020, followed by a human mission to another asteroid in the mid-2020s.

Japan also plans to launch an asteroid sample return mission in 2018.

Source

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