Monroe Posted September 5, 2014 Share Posted September 5, 2014 They keep coming ... just discovered on August 31st. NASA: Asteroid Will Pass ‘Very Close’ To Earth On Sunday http://tampa.cbslocal.com/2014/09/04/nasa-asteroid-will-pass-very-close-to-earth-on-sunday/ September 4, 2014 TAMPA, Fla. (CBS Tampa) — NASA announced that a small asteroid will safely pass “very close” to Earth on Sept. 7. The asteroid, designated 2014 RC, will be roughly over New Zealand at the time of closest approach, which will be about 2:18 pm EDT based on current calculations. Astronomers estimate that the asteroid is about 60 feet in size. On the night of Aug. 31, the asteroid was first discovered by the Catalina Sky Survey near Tucson, Ariz., and was detected independently the next night by the Pan-STARRS 1 telescope that is located in Hawaii. The orbit of 2014 RC was confirmed by both the Catalina Sky Survey and the University of Hawaii during follow-up observations. t will be about 25,000 miles away at the time of its closest approach to Earth. It won’t be observable to the unaided eye, but amateur astronomers with small telescopes might be able to spot the fast-moving appearance of the asteroid. The asteroid doesn’t seem to pose any threat to Earth or satellites in space. It will prove to be an opportunity for researchers to observe and gather more information about asteroids.... Link to comment Share on other sites More sharing options...
Monroe Posted September 8, 2014 Author Share Posted September 8, 2014 Possibly a small piece of the asteroid from the Sunday fly-by may have hit the Earth ... pretty good explosion from that small piece, wherever it came from. The whole asteroid was considered "small" and this maybe was just a piece. 'Meteorite' Smashes Into Nicaraguan Capital http://news.yahoo.com/meteorite-smashes-nicaraguan-capital-230034550.html 2 hours ago - 08 September 2014 Managua (AFP) - A mysterious explosion that rocked Nicaragua's crowded capital Managua, creating a large crater, appears to have been caused by a small meteorite, officials said Sunday. Amazingly, in a sprawling city of 1.2 million people, the impact near the international airport did not cause any known injuries, but it did leave a crater measuring 12 meters (39 feet) across and was felt throughout the capital late on Saturday. Nicaraguan authorities believe it was a piece of the small asteroid dubbed "2014 RC," which passed very close to Earth on Sunday and was estimated by astronomers to be about 20 meters big, or the size of a house. "We are convinced that this was a meteorite. We have seen the crater from the impact," said Wilfredo Strauss of the Seismic Institute. The meteorite appeared to have hurtled into a wooded area near the airport around midnight and the hit was so large that it registered on the instruments Strauss's organization uses to size up earthquakes. "You can see two waves: first, a small seismic wave when the meteorite hit earth, and then another stronger one, which is the impact of the sound," he said. Government officials and experts visited the impact site on Sunday. One of them, William Martinez, said it was not yet clear if the meteorite burned up completely or if it had been blasted into the soil. "You can see mirror-like spots on the sides of the crater from where the meteorite power-scraped the walls," Martinez said. Government spokeswoman, First Lady Rosario Murillo, said Managua would be in contact with the US Geological Service to try to get more information about "this fascinating event" in the Central American nation, one of Latin America's poorest countries. People who live near the crater told local media they heard a blast they took for an explosion, and that liquid, sand and dust were blown through the air, which smelled like something had burned. There were no reported injuries because the impact was in a wooded spot, and flights at the airport were not affected. NASA said last week that the asteroid 2014 RC, at the time of closest approach, would be approximately one-tenth the distance from the center of Earth to the moon, or about 25,000 miles (40,000 kilometers). It had been projected to be roughly over New Zealand at the time of its closest approach, which astronomers had calculated would be on Sunday at about 1818 GMT.... Link to comment Share on other sites More sharing options...
jaclaz Posted September 9, 2014 Share Posted September 9, 2014 (edited) .... "We are convinced that this was a meteorite. We have seen the crater from the impact," said Wilfredo Strauss of the Seismic Institute. .... One of them, William Martinez, said it was not yet clear if the meteorite burned up completely or if it had been blasted into the soil. ...Or if by appropriate use of "magic" the meteorite disappeared (and is going to re-materialize itself soon as an item for sale on e-bay ) jaclaz Edited September 9, 2014 by jaclaz Link to comment Share on other sites More sharing options...
dencorso Posted September 9, 2014 Share Posted September 9, 2014 Its authenticity, however, will be real hard to prove, because any bean-sized quartz or metal droplet should be enough to cause a 12 m crater and, being already hot from the plunge in Earth's atmosphere, it really might be vaporized on impact and, well, "disappear"... What size crater should be expected for, say, a baseball ball hitting the dirt at the full speed 2014 RC's travelling at?Surely way more than 12 m, in my opinion... Link to comment Share on other sites More sharing options...
jaclaz Posted September 9, 2014 Share Posted September 9, 2014 (edited) It's authenticity, however, will be real hard to prove, because any bean-sized quartz or metal droplet should be enough to cause a 12 m crater and, being already hot from the plunge in Earth's atmosphere, it really might be vaporized on impact and, well, "disappear"... Sure , but - by the same token - can also be recreated, so I wouldn't be surprised is several specimens would "re-appear" for sale. What size crater should be expected for, say, a baseball ball hitting the dirt at the full speed 2014 RC's travelling at?Surely way more than 12 m, in my opinion...Try using the very convenient Computing Crater Size from Projectile Diameter online calculator :http://www.lpl.arizona.edu/tekton/crater_c.html jaclaz Edited September 9, 2014 by jaclaz Link to comment Share on other sites More sharing options...
Monroe Posted September 9, 2014 Author Share Posted September 9, 2014 For crying out loud !!! ... jaclaz, is there anything that you can't FIND ??? ... a "Crater Calculator" ! Unbelievable ... Link to comment Share on other sites More sharing options...
Monroe Posted September 9, 2014 Author Share Posted September 9, 2014 (edited) There was a large meteor/asteroid that hit Arizona around 50,000 years ago. It is called Meteor Crater and there was never a meteorite found. Several theories exist that it vaporized, exploded or bounced into the Pacific Ocean ... at least those theories were around in the 50s and 60s. http://meteorcrater.com/ Meteor Crater is nearly one mile across, 2.4 miles in circumference and more than 550 feet deep. It is an international tourist venue with outdoor observation trails, air conditioned indoor viewing, wide screen movie theater, Interactive Discovery Center, unique gift and rock shop, and Astronaut Memorial Park at the Visitor Center located on the crater rim. Mystery of Arizona's Meteor Crater Solved http://www.space.com/834-mystery-arizona-meteor-crater-solved.html The space rock that carved Meteor Crater in Arizona hit the planet much more slowly than astronomers once figured, but still 10 times faster than a rifle bullet. The new analysis, announced today, explains why there's a lot less melted rock in the crater than expected. The mystery has dogged researchers for years. The big hole in the ground -- 570 feet deep and 4,100 feet (1.25 kilometers) across -- was blown into existence 50,000 years ago by an asteroid roughly 130 feet (40 meters) wide. Previous calculations had the rock slamming into the ground at no less than 34,000 mph (15 km/sec), based in part on the expected speeds of large meteors in relation to Earth. Such an impact ought to have generated more melted rock in and around the crater than what's been found...... Now there is some thought that the crater in Nicaragua might not be. I'm glad that I said "possibly" in my first post. Scientists Doubt That Meteor Caused Crater In Nicaragua http://knau.org/post/scientists-doubt-meteor-caused-crater-nicaragua September 9, 2014 We reported on Monday that a meteor, thought possibly to be a chunk of an Earth-passing asteroid, was the cause of a 40-foot crater outside the international airport in the Nicaraguan capital. But astronomers and NASA scientists are now casting doubt on that possibility. The biggest mystery is that no one so far has reported seeing a flash of light in the sky that would be expected to accompany such a meteor strike. "While a meteoritic origin for this crater cannot be ruled out with absolute certainty, the information available at this time suggests that some other cause is responsible for its creation," NASA's blog concludes.... Edited September 9, 2014 by monroe Link to comment Share on other sites More sharing options...
dencorso Posted September 10, 2014 Share Posted September 10, 2014 It's authenticity, however, will be real hard to prove, because any bean-sized quartz or metal droplet should be enough to cause a 12 m crater ... [...] What size crater should be expected for, say, a baseball ball hitting the dirt at the full speed 2014 RC's travelling at?Surely way more than 12 m, in my opinion... Try using the very convenient Computing Crater Size from Projectile Diameter online calculator :http://www.lpl.arizona.edu/tekton/crater_c.html Thanks, jaclaz, you do rock! :yes It seems I was off-scale by a factor of about 100!!! Results for computing crater size from projectile diameterYour Inputs: <<< a lump of pure iridium, the size of a baseball ball ... >>>Projectile Descriptors Projectile Diameter 0.076 meters Projectile Density 22650 kg/m3Impact Conditions Impact Velocity 50 km/sec Impact Angle 90 degreesTarget Descriptors Target Density 1000 kg/m3 Acceleration of Gravity 9.8 m/sec2 Target Type loose sandResultsThe three scaling laws yield the following transient crater diameters (note that diameters are measured at the pre-impact surface. Rim-to-rim diameters are about 1.25 times larger!)Yield Scaling 10.8 metersPi Scaling (Preferred method!) 9.2 metersGault Scaling 22 metersCrater Formation Time 0.588 secondsUsing the Pi-scaled transient crater, the final crater is a Simple crater with a rim-to-rim diameter of 14.4 meters.This impactor would strike the target with an energy of 6.51 x 10^9 Joules (1.55 x 10^-6 MegaTons).A baseball ball made of iridium is required for a 14.4 m crater!!! Wow!!! A pea-sized droplet of iridium should yield a crater of less than 3 m (or less than 2 m, if made of iron)... Link to comment Share on other sites More sharing options...
jaclaz Posted September 10, 2014 Share Posted September 10, 2014 @monroeFacts:1) witnesses for loud boom (and possibly for burning smell)2) no witnesses (yet) for flash of light in the sky3) crater 4) no traces of meteorite found 5) seismic trace of event recorded Opinions:1) "experts" quoted about meteorite "vaporized"2) "astronomer" quoted attributing the meteorite to fragment of 2014RC3) "seismologist" quoted saying that the seismic trace is compatible to an impact4) "other experts" not convinced http://en.wikipedia.org/wiki/Duck_test Maybe if it sounds like a bomb and smells like a bomb, it could be a bomb? @dencorsoI don't know. The 90 degrees simply don't sound "right", and I am not convinced about the speed. Wouldn't a falling meteorite have a rather acute angle (something like 20° or less)? Wouldn't *anything* falling through atmosphere tend to "stabilize" at a given "terminal velocity"?http://en.wikipedia.org/wiki/Terminal_velocity(or is the initial speed so high that it hits ground before being slowed down?) In any case:50*60*60=180,000 km/h 180,000/1,225= Mach 146 ! that sounds like 5 times "re-entry speed"http://en.wikipedia.org/wiki/Hypersonic_speed What you can be rather sure is that "loose sand" weights much more than 1000 kg/mc, depending on mineral composition, anything between 1600 and 2200 kg/m3 would be more accurate. jaclaz Link to comment Share on other sites More sharing options...
dencorso Posted September 11, 2014 Share Posted September 11, 2014 I think it might be around 30 degrees... but then I decided to go for it and try to shoot for maximums, even if somewhat unlikely, just to see what should be the maximum damage attributable to a baseball ball sized lump of the densest metal conceivable. An interesting obsevation is that the "Pi Scaling (Preferred method!)" diverges for 60 degrees: there must be a bug in its programming (although that value can be estimated by interpolating, of course). Link to comment Share on other sites More sharing options...
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