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http://www.lowell.edu/press_room/rel...ermes_rls.html
For Immediate Release October 21, 2003 Contact: Edward Bowell, Director LONEOS (928) 774-3358 ext. 219 or Brian Skiff, Observer LONEOS ext. 224 NEAR-EARTH ASTEROID HERMES RE-SPOTTED, 66 YEARS LATER UPON CLOSE OBSERVATION LONG-LOST OBJECT IS BRIGHT BINARY Flagstaff, AZ--The re-discovery of Hermes started early on October 15th by Brian Skiff of the Lowell Observatory Near-Earth-Object Search (LONEOS). Not seen since 1937, asteroid 1937 UB (Hermes) continues to astonish and excite astronomers worldwide. Further observations revealed late yesterday that Hermes is actually two objects--called a binary--circling around one another while about to pass by Earth again. "This re-sighting of Hermes is the Holy Grail of near-Earth asteroid discovery," said Edward Bowell, LONEOS Director. "Its orbit has been better calculated and observers have confirmed its re-appearance and also shown its binary nature... well, an asteroid's return just does not become more profound than this." The binary object was some 19 million miles out at the time of re-discovery last Wednesday, nearly 66 years after it was first seen. Hermes, which poses no threat to Earth, will make its closest approach on November 4th. By then it will be 4 million miles away and bright enough for amateurs to see using backyard telescopes. The same day Skiff captured the first images of Hermes, Discovery Communications, Inc. and Lowell Observatory announced a partnership to build the new Discovery Channel Telescope near Flagstaff, Arizona. (http://www.lowell.edu/press_room/rel...s/dct_rls.html) One research objective for this new $30-million, 4.3-meter telescope will be to significantly accelerate the search for near-Earth objects, including those smaller than Hermes. First images of the kilometer-size asteroid were captured by a CCD camera during early morning observation through the LONEOS 24-inch Schmidt telescope. More than six decades ago, Hermes was discovered by Karl Reinmuth at Heidelberg, Germany on October 25, 1937. Fast forward to a few days ago when Andrea Boattini of Instituto di Astrofisica Spaziale, Rome, Italy, and Timothy Spahr of the Minor Planet Center in Cambridge, Massachusetts analyzed the new positions of Hermes and determined what it was: the long-lost asteroid. "Since we find new near-Earth asteroids fairly regularly (I found, for instance, two near-Earth asteroids the same night), my only reaction upon finding it was that it was unusually bright," Skiff told BBC News Online on Friday. Up before dawn, Spahr quickly posted Skiff's discovery on the web, alerting astronomers to follow the asteroid. James Young, at the Jet Propulsion Laboratory's Table Mountain Observatory in California, was the first to respond, just five hours later. Spahr then located observations made on October 5 by the Near-Earth Asteroid Tracking program (http://neat.jpl.nasa.gov), LONEOS observations from September 28, and unpublished observations made by the MIT Lincoln Laboratory Near Earth Asteroid Research program (http://www.ll.mit.edu/LINEAR), extending the observational arc back to August 26 (http://cfa-www.harvard.edu/mpec/K03/K03T74.html). At this point, the identification with Hermes was clear from the similarity of the orbits from the 1937 and 2003 sightings, but it was not a simple matter to compute an orbit that linked all the observations together. Steven Chesley and Paul Chodas of the Jet Propulsion Laboratory found that Hermes' trajectory is very chaotic due to frequent close encounters with the Earth and Venus. Following its flyby of the Earth in 1937 at a distance of 460,000 miles (just 1.8 times the Moon's distance), Hermes made an unobserved close approach to the Earth in 1942 of just 1.6 lunar distance. Using JPL's Sentry impact monitoring software, Chesley and Chodas were able to find twelve distinct dynamical pathways that produced an encounter in 1937. Picking out the true orbit was then an easy matter , and led to the further prediction that Hermes will not approach the Earth more closely than 8 lunar distances within the next century (http://neo.jpl.nasa.gov/news/news140.html). On October 16, Andrew Rivkin and Richard Binzel of MIT observed a spectrum of Hermes using the NASA Infrared Telescope Facility in Hawaii, and were able to ascertain that the asteroid is of a type known as S class. Because the surfaces of S-class asteroids reflect, on average, 24% of the sunlight falling on them, Rivkin and Binzel were able to deduce that Hermes is 0.9 km (about 1,000 yards) in diameter. Over the next few days, the world's most powerful radar, the 1,000-foot dish, at Arecibo, Puerto Rico, projected radar beams on to the asteroid and captured the faint returning echoes. Jean-Luc Margot, of the University of California, Los Angeles, and his team saw that the asteroid is strongly bifurcated. Two separate components, of roughly equal size and almost in contact, are revolving about their common center of mass in up to 21 hours. It appears that the components have tidally evolved into a situation where their spin period is equal to their orbital period and therefore present the same face to one another all the time, just like the Earth-Moon system. There are now about 10 radar-observed binary near-Earth asteroids, about 1 in 6 of NEAs larger than 200 m in diameter. "We certainly did not expect to find a binary with roughly equal-sized components," said Margot. "All the binary NEAs that we have imaged so far show a secondary that is only a fraction of the size of the primary." Amateur and professional astronomers are collaborating to observe the way Hermes changes in brightness as its components rotate. Eventually, they should be able to determine the components' orbital plane, an accurate period of revolution, and, perhaps, the shapes of the individual bodies. See http://www.asu.cas.cz/~asteroid/binneas.htm for a list of binary NEAs. The only near-Earth object not also identified by number, Hermes shares a name in Greek mythology with the son of Zeus, messenger of the gods, god of science, commerce, eloquence, and arts of life. "The name `Hermes' also means hastener, and representations of him are symbolic of the messenger or the speed and majesty in flight," according to Schmadel's Dictionary of Minor Planet Names. Lowell Observatory was founded in 1894 by Percival Lowell with a mission to pursue the study of astronomy, especially the study of our Solar System and its evolution; to conduct pure research in astronomical phenomena; and to maintain quality public education and outreach programs to bring results of astronomical research to the general public. Visit http://www.lowell.edu; and Friends of Lowell at http://www.lowell.edu/friends/. LONEOS is one of five programs funded by NASA to search for asteroids and comets that may approach our planet closely. Their current goal is to discover 90% of near-Earth asteroids larger than 1 km in diameter by 2008. There are thought to be about 1,200 such asteroids. For more information on the discovery and images of Hermes, visit the LONEOS website at http://asteroid.lowell.edu/asteroid/loneos/loneos.html. #END# |
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"Ron Baalke" wrote in message
... http://www.lowell.edu/press_room/rel...ermes_rls.html For more information on the discovery and images of Hermes, visit the LONEOS website at http://asteroid.lowell.edu/asteroid/loneos/loneos.html. Interesting page, but, you know, when I go to a webpage and the first thing I see is this: "The risk you face of dying as a result of an asteroid impact is about 1 in 20,000, the same risk you face of dying in a plane crash. - Source: Spaceguard Survey" The fact that that's obviously a completely bogus statistic.....considering, oh...... I can search the web and find many people who have died in plane crashes, but, there's not one instance in recorded history of anyone dying in an asteroid impact...... makes that rather suspect.... |
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algomeysa2 wrote:
"Ron Baalke" wrote in message ... http://www.lowell.edu/press_room/rel...ermes_rls.html For more information on the discovery and images of Hermes, visit the LONEOS website at http://asteroid.lowell.edu/asteroid/loneos/loneos.html. Interesting page, but, you know, when I go to a webpage and the first thing I see is this: "The risk you face of dying as a result of an asteroid impact is about 1 in 20,000, the same risk you face of dying in a plane crash. - Source: Spaceguard Survey" The fact that that's obviously a completely bogus statistic.....considering, oh...... I can search the web and find many people who have died in plane crashes, but, there's not one instance in recorded history of anyone dying in an asteroid impact...... makes that rather suspect.... Its "a priori" vs. "a postiori" statistics ... all statistics are "bogus" if you do not understand the basis. |
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In article .net,
algomeysa2 wrote: "The risk you face of dying as a result of an asteroid impact is about 1 in 20,000, the same risk you face of dying in a plane crash. - Source: Spaceguard Survey" The fact that that's obviously a completely bogus statistic.....considering, oh...... I can search the web and find many people who have died in plane crashes, but, there's not one instance in recorded history of anyone dying in an asteroid impact...... makes that rather suspect.... Depends on how long a period the number is averaged over. The chances of dying from an asteroid impact tend to be dominated by extremely rare events that kill a sizable fraction of the human race, so to check on that statistic, you need a very long averaging period indeed -- recorded history is much too short. "Misleading" is a better word than "bogus". -- MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer pointing, 10 Sept; first science, early Oct; all well. | |
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algomeysa2 writes:
Interesting page, but, you know, when I go to a webpage and the first thing I see is this: "The risk you face of dying as a result of an asteroid impact is about 1 in 20,000, the same risk you face of dying in a plane crash. - Source: Spaceguard Survey" The fact that that's obviously a completely bogus statistic.....considering, oh...... I can search the web and find many people who have died in plane crashes, but, there's not one instance in recorded history of anyone dying in an asteroid impact...... makes that rather suspect.... On what basis do you call it a fact that it is "a completely bogus statistic"? In reality, the statistic is not at all bogus. It's your reasoning that's bogus. You're trying to compare a relatively high frequency, low fatality event (plane crashes) with a relatively low frequency, high fatality event (asteroid impacts). Suppose an asteroid impact that causes a mass extinction (let's say 50 percent of the human population eventually dies as a result) happens once every 10 million years. Well, the current global population is about 6 billion. That makes for an average death rate of 600 people per year. How many people die in plane crashes each year? The number is comparable to within the limits of this execise. |
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Jonathan Silverlight writes:
algomeysa2 writes: Interesting page, but, you know, when I go to a webpage and the first thing I see is this: "The risk you face of dying as a result of an asteroid impact is about 1 in 20,000, the same risk you face of dying in a plane crash. - Source: Spaceguard Survey" The fact that that's obviously a completely bogus statistic.....considering, oh...... I can search the web and find many people who have died in plane crashes, but, there's not one instance in recorded history of anyone dying in an asteroid impact...... makes that rather suspect.... On what basis do you call it a fact that it is "a completely bogus statistic"? In reality, the statistic is not at all bogus. It's your reasoning that's bogus. You're trying to compare a relatively high frequency, low fatality event (plane crashes) with a relatively low frequency, high fatality event (asteroid impacts). Suppose an asteroid impact that causes a mass extinction (let's say 50 percent of the human population eventually dies as a result) happens once every 10 million years. Well, the current global population is about 6 billion. That makes for an average death rate of 600 people per year. How many people die in plane crashes each year? The number is comparable to within the limits of this execise. I would say that shows how completely bogus the statistic is. What you would say is irrelevant; the facts are relevant, and it's a fact that there is nothing wrong with the statistic; the problem is in its correct interpretation. The actual number of people exposed to the danger of dying in a plane crash is a tiny fraction of the number now living in various degrees of poverty on Earth. But it is an absolute certainty that some of them will die in a plane crash. Which does nothing to substantiate your claim that the statistic is bogus. And the number of people who have lived in the past ten million years is vastly more than the current population - Clarke's "behind every man now alive stand thirty ghosts" comes to mind. Illogical, given that you can't be killed if you're already dead. The relevant number is therefore the number of people killed in an asteroid impact, which has to be some fraction less than or equal to unity of the number of people living at the time. In fact 10 million years ago man didn't exist. I can imagine one dinosaur telling another, some 65 million years ago, that 10 million years earlier, dinosaurs didn't exist. Does that somehow make the statistic of their death rate "bogus"? But then no-one's interested in spending money on solving problems that actually kill people. After all, we've spent trillions to ensure the destruction of all life on Earth. Actually, money has been spent disproportionately on solving problems that actually kill people: disease, automobile safety, floods, aircraft safety, highway safety, and so on. |
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In article ,
Mary Shafer wrote: Depending on whether Tunguska was a comet or an asteroid, there is a finite probability that one or more people died from asteroid impact... And that was only about a century ago, too. It's easy to forget that when you go back as little as a few centuries, "recorded history" is the history of only a modest fraction of the world... and if you go back a few thousand, "recorded history" is small fragments of the history of a few isolated locations. Absence of evidence is not evidence of absence. However, in these bureaucratic days it's easy to assume that such fatalities will be reported... An even more modern example: Several years before Skylab itself came down, the S-II stage of the Saturn V that launched it -- quite a bit bigger than Skylab itself -- came down, in pieces, in central Africa. We think it didn't kill anyone... but nobody is actually sure of that. -- MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer pointing, 10 Sept; first science, early Oct; all well. | |
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Jonathan Silverlight wrote:
I would say that shows how completely bogus the statistic is. Please do not display your innumeracy in public. Paul |
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