http://neo.jpl.nasa.gov/news/news185.html
Reports of Meteorite Strike in Nicaragua and Update on Asteroid 2014 RC NASA/JPL Near-Earth Object Program Office September 8, 2014 Reports in the media over the weekend that a small meteorite impacted in Nicaragua have yet to be confirmed. A loud explosion was heard near Managua's international airport Saturday night, and photos of a 24-meter (80-foot) crater have been circulated. As yet, no eyewitness accounts or imagery have come to light of the fireball flash or debris trail that is typically associated with a meteor of the size required to produce such a crater. Since the explosion in Nicaragua occurred a full 13 hours before the close passage of asteroid 2014 RC, these two events are unrelated. As predicted, the small asteroid 2014 RC flew safely past the Earth at 18:01 UT (2:01 pm EDT, 11:01 am PDT) on September 7 at a distance of 33,550 km (20,800 miles) above the Earth's surface. Astronomers around the world took the opportunity to observe this fairly rare event, and learned that the asteroid is about 12 meters (40 feet) in size and is spinning very rapidly. R. P. Binzel, D. Polishook (MIT) and S. J. Bus (Univ. Hawaii) observed 2014 RC from NASA's Infrared Telescope Facility (IRTF) on Sept. 6 in near-infrared wavelengths. From their spectra, they conclude that the asteroid belongs to the "Sq-class", which has an average albedo (reflectivity) of 24%. Based on the available measurements of the asteroid' intrinsic brightness, they conclude that 2014 RC is about 12 meters (40 feet) across, roughly the size of a school bus. This puts 2014 RC at about one-half the size of the February 15, 2013 Chelyabinsk impactor. Lance Benner and Marina Brozovic, Jet Propulsion Laboratory, meanwhile, reported that radar observations of 2014 RC taken at the Goldstone site in southern California on September 6-7 were weaker than expected due to an extreme Doppler broadening of the radar echoes. If the 12-meter size is adopted and an equatorial radar view is assumed, then the radar measurements indicate an extremely fast rotation rate of at least several revolutions per minute. Following up on this preliminary result, A. Thirouin, B. Skiff, and N. Moskovitz (Lowell Observatory) analyzed the brightness variations of 2014 RC across multiple nights using Lowell Observatory' 1.1m Hall telescope, Lowell's 4.3m Discovery Channel Telescope and NASA's IRTF. A subset of these images have been combined into an movie which can be downloaded here: http://www2.lowell.edu/users/nmosko/2014RC_flyby.gif These data indicate a best fit rotation period of about 15.8 seconds, and a low light curve amplitude of ~0.1 magnitude. This is the fastest rotating asteroid observed to date, roughly 50% faster than the previous record holder. ______________________________________________ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
