On February 15, 2013, an asteroid will come close enough to Earth to knock satel

[Mark]

January 9, 2013 – SPACE - Near Earth Asteroid (NEA) 2012 DA14 has its annual flyby of the earth on February 15, 2013. Its projected orbit, according to NASA, will bring it well within the orbits of geosynchronous satellites currently orbiting our planet. NASA has indicated that there is no danger of this asteroid impacting our planet, however they have not ruled out our gravity changing the asteroids orbital pattern. NEA 2012 DA 14 was discovered on February 23, 2012 by the Observatorio Astronómico de Mallorca (OAM), near the Spanish city of La Sagra. According to NASA’s Near Earth Object Program, NEO, the asteroid will pass the earth at a distance of 21,000 miles, putting the asteroid’s trajectory in between the earth and the satellites orbiting our planet. Geosynchronous satellites orbiting our planet orbit at a distance of roughly 26,200 miles above the earth. Geostationary orbiting objects orbit at a distance of roughly 22,236 miles above the Earth’s equator. These objects are considered to be in High Earth Orbit (HEO). Any object in space considered to be in a Low Earth Orbit (LEO) is approximately 1250 miles above the equator. The term Medium Earth Orbit (MEO) refers to an orbiting object approximately 12,500 miles above the Earth’s equator, in between objects in an LEO and a HEO, geosynchronous orbit.
 
With Near Earth Asteroid 2012 DA 14′s flyby falling somewhere in between geosynchronous satellite orbit, and objects orbiting in a Medium Earth Orbit pattern, the potential for this NEO impacting other objects orbiting our planet appears to be almost guaranteed. Could one of these objects be impacted by the asteroid and then be propelled back into our atmosphere? The chance of this happening is low, and NASA has not indicated if this potential happenstance will occur. Asteroid 2012 DA 14 has an estimated diameter of about 45 meters, and a mass of roughly 130,000 metric tons, making it a medium-sized asteroid. If Asteroid DA 14 were to impact the Earth, it would do so with the energy of 2.4 Megatons. Additionally NASA estimates the closest it can get to the earth will be 17,000 miles above the equator. NASA continually tracks these asteroids, through their Near Earth Object Program (NEO) in association with the Jet Propulsion Laboratory (JPL). NASA’s Wide-field Infrared Survey Explorer program (WISE) searches the skies of our solar system making observations in an effort to assess Potentially Hazardous Asteroids (PHA) orbiting close to our planet. Potentially hazardous asteroids are a smaller subset of the larger group called the Near Earth Asteroids (NEA) that have close orbits to the Earth’s and are big enough to survive passing through our atmosphere and causing damage of great proportions. The asteroid hunting portion of the WISE program is called NEOWISE. “The NEOWISE analysis shows us we’ve made a good start at finding those objects that truly represent an impact hazard to earth,” said Lindley Johnson, program executive for the Near Earth Object Observation Program at NASA. “But we’ve many more to find, and it will take a concerted effort during the next couple of decades to find all of them that could do serious damage or being mission destination in the future. NASA’s NEOWISE project, which wasn’t originally planned as part of WISE, has turned out to be a huge bonus,” said Amy Mainzer, NEOWISE principal investigator, at NASA’s Jet Propulsion Laboratory in Pasadena California. “Everything we can learn about these projects helps us understand their origins and fate. Our team was surprised to find the over abundance of low inclination PHA’s. Because they will tend to make more close approaches to earth, these targets can provide the best opportunities for the next generation of human and robotic exploration.” Pres. Obama has called for NASA to access an asteroid in orbit for the purposes of exploring ways to divert its orbit away from the earth in the event of a potential impact. A new project, initiated by scientists at California’s Institute for Space Studies, would put an asteroid into orbit around the Earth’s moon, giving us the ability to study it from a closer distance then the asteroids standard orbit. The majority of asteroids orbiting in our solar system do so in the main asteroid belt, between the planets Mars and Jupiter. –Guardian

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[Mark]

February 15, 2013 – SPACE - An asteroid which is to hurtle close to the Earth tomorrow may experience a seismic jolt as it passes through our planet’s gravitational field, scientists suggest. The 45m asteroid, named 2012 DA14, will fly by at 7.8 km/s at a distance of just 27,000 km from Earth. It will be visible in New Zealand skies from about 2.30am (although not with a naked eye), but will make its closest approach to the Earth about 8.25am. It is forecast to be the closest recorded asteroid, passing well inside the geostationary ring, where many communication satellites are located. While Earth has experienced many tremors from asteroids striking our planet, new research by Richard Binzel, a professor of planetary science at the Massachusettes Institute of Technology, suggests many near-Earth asteroids experience a seismic jolt when they pass too close to our planet’s gravitational field. “We are going to be looking closely for evidence of seismic activity on 2014 DA14 as it passes by,” Binzel said. “This is the first case of an object coming close enough to experience quakes and where we have enough notice to plan observations.” The idea of asteroid-quakes came to Binzel when he was pondering a mystery about “space-weathered” asteroids. “As asteroids move through space, they slowly turn dark-red. This phenomenon, called ‘space weathering,’ is caused by long exposure to cosmic rays and solar radiation. For decades, however, we have known about a handful of small asteroids that looked light and fresh; they were not space weathered.” Calculating the orbits of the non-weathered asteroids, Binzel and colleagues discovered they had all had close encounters with Earth in the past million years. “We believe they were ‘shaken up’ by their encounters with Earth,” he said. “Gravitational forces during the flybys can stretch, rattle, and torque these asteroids, causing dark, space-weathered material on the surface to be overturned, revealing the fresh stuff underneath.” Unlike on Earth, there is no Richter scale for asteroids. Instead, Binzel measures the force of the quakes in units of gravitational acceleration, or gees. “These asteroids experience [seismic activity] in the milli- to micro-g range,” Binzel said. “That might not sound like much, but remember these are small bodies. Gravity is not very strong, so just a little shaking or stretching goes a long way.” Binzel believed an asteroid floating beside an asteroid experiencing such a quake would see the surface “slowly sway or rock by a few centimeters. Other things to look for would be puffs of asteroid-dust rising from the surface and gentle avalanches on the steepest slopes of craters.” MIT post-doctorate Nick Moskovitz, who works with Binzel, is coordinating observations with worldwide observatories, including New Zealand’s Mt John Observatory, to determine the colour spin, shape, and reflectivity of 2012 DA14 as it passes by. Changes in any of these quantities might be a sign of a quake. “We stand to learn a lot from the observations,” Binzel said. –NZ Herald

[Mark]

February 16, 2013 – HAVANA — An object fell from the sky over central Cuba on Thursday night and turned into a fireball “bigger than the sun” before it exploded, a Cuban TV channel reported Friday, citing eyewitnesses. Some residents in the central province of Cienfuegos were quoted as saying that at around 8 p.m. local time Thursday (0100 GMT Friday) they saw a bright spot in the sky comparable to a bus in size. The object then turned into a fireball “bigger than the sun,” said the witnesses, adding that several minutes later they heard a loud explosion. One resident told the TV station that his house shook slightly in the blast. Cuban experts have been dispatched to the area to look for possible remains of the meteor-like object, said the report. It remains unknown whether the reported phenomenon in Cuba is related to Friday’s meteor strike in central Russia, which set off a shockwave that shattered windows and left some 1,000 people injured. –Xinhuanet

[Mark]

Fireball seen in Bay Area skies: It may not have been as spectacular as the space rock that streaked across the skies above Russia late Thursday, but the Bay Area’s close encounter with a meteor Friday night was drawing its own attention on social networks. Comments on Twitter indicated the object that flashed across the horizon around 7:45 p.m. was blue in color and visible throughout the Bay Area and large areas of the West Coast, with at least one reported sighting in Washington State. Amateur video footage broadcast on KTVU-2 showed a bright streak lasting approximately five seconds that appeared to head downward. Some viewers described it as a firework in the night sky. One commenter on Twitter, who said they saw the meteor while driving in a car in Cupertino, said the object appeared to be headed west. Scanner traffic at the Contra Costa County Sheriff’s Office indicated that they were aware of the event, but a dispatcher said they had not received any emergency calls related to it. Gerald McKeegan, an astronomer with the Chabot Space and Science Center in Oakland, was at the center Friday evening for its weekend stargazing sessions with free access to the center’s large telescopes, but he said they did not spot the meteor there. He said that the center received phone calls from people who reported seeing the meteor. Based on their reports, McKeegan said it may have been what astronomers call a “sporadic meteor,” an event that can happen several times a day but most of the time happens over the ocean, away from human eyes, and brings as much as 15,000 tons of space debris to Earth each year. Meteors, hunks of rock and metal from space that fall to Earth, burn up as they go through the atmosphere, which is what apparently caused Friday night’s bright flash of light, McKeegan said. It was likely smaller than another meteor that landed in the Bay Area in October, which caused a loud sonic boom as it fell, breaking apart and spreading rocks, called meteorites, in the North Bay, McKeegan said. –Mercury News