Wednesday, February 6, 2013

Deep Impact Spacecraft Eyes Comet ISON 2013

NASA's Deep Impact spacecraft has acquired its first images of comet C/2012 S1 (ISON). The images were taken by the spacecraft's Medium-Resolution Imager over a 36-hour period on Jan. 17 and 18, 2013, from a distance of 493 million miles (793 million kilometers). Many scientists anticipate a bright future for comet ISON; the spaceborne conglomeration of dust and ice may put on quite a show as it passes through the inner solar system this fall.

"This is the fourth comet on which we have performed science observations and the farthest point from Earth from which we've tried to transmit data on a comet," said Tim Larson, project manager for the Deep Impact spacecraft at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The distance limits our bandwidth, so it's a little like communicating through a modem after being used to DSL. But we're going to coordinate our science collection and playback so we maximize our return on this potentially spectacular comet." Read more here



But before comet ISON arrives on Dec. 26, 2013 (ISON will not be a threat to Earth - getting no closer to Earth than about 40 million miles) the asteroid 2012 DA14 will pass within about 3.5 Earth radii of the Earth's surface on February 15, 2013. It will pass inside the geosynchronous satellite ring, located about 35,800 kilometers (21,748 miles) above the equator. The impact energy is listed as 2.41 megatons of TNT.

NASA says this asteroid is not Earth bound. The asteroid rates as a 0 on the Torino Scale impact hazard scale. At its closest approach, the asteroid could be as close as 14,000 miles from the Earth. The small asteroid is estimated to be about 60 meters (about 200 feet) across. It is not likely to collide with any satellites. However, when it flies past Earth it will be under the influence of the Earth’s gravitational field. Passing close to the Earth could cause the asteroid's orbit to change and bring it closer to Earth - or father away from Earth.

Telephone and television satellites are parked in geostationary orbits in the Clarke Belt at 22,500 miles with less than two degree spacing.

2012 DA14 will pass through our communication satellite belt twice: First time - On its way toward Earth and Second time - back through the belt again on its way out. Angle at which the object 2012 DA14 enters and leaves the Clarke Belt will determine the possibility of taking out one or more satellites.

It is unknown what other rocks 2012 DA14 may have traveling along with it towards Earth. If this asteroid, 60 meters in diameter, will, if Earth’s gravity impacts its trajectory as some believe, strike North Africa with the force of 2000 nuclear weapons, a collision not unlike that of the "Tunguska event” of 1908.

 

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