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Show ii iiiwriip in - . SOUTHERN UTAH NEWS FEATURE - WEDNESDAY AUGUST 19, 1998 13 s By Barbara Pyles There are many scenarios as to what could have caused the dinosaur population to become extinct. Some scientists say they were wiped out by a large asteroid or comet that struck in the area of the Yucatan Peninsula in Mexico G5 million years ago. ...an asteroid or comet about 5 miles in diameter (about the size of Mt. Everest) headed directly toward the Earth with a velocity of about 20 miles per second, more than 1 0 times faster than our fastest bullets. Many such large objects may have come close to the Earth, but this was the one that finally hit. It hardly noticed the air, as it plunged through the atmosphere in a fraction of a second, momentarily leaving a trail of vacuum behind it. It hit the Earth with such force that it and the rock near it were suddenly heated to a temperature ofover a million-degre- e Celsius, several hundred times hotter than the surface of the sun .. . before a minute had passed, the expanding crater was 60 miles across and 20 miles deep. (It would soon grow even larger.) Hot vaporized material from the impact had already blasted its way out through most of the atmosphere to an altitude of 15 miles. Material that a moment earlier had been glowing plasma was beginning to cool and condense into dust and rock that wouldbe spread worldwide. The entire Earth recoiled from the impact, but only a few hundred feet. The length of the year - !' -,' - v V "S, x ,nililllliillwUIIWMKn ml! JallMill' o Ky largest earthquakes humans have experienced, probably a million times more energetic than the one that devastated San Francisco in 1906 ...it is impossible to guess all the effects, or how long they lasted. The asteroid quickly punched through the water layer . . . the splash created a great tsunami, or tidal wave, which grew hundreds of feet high as it swept toward shore . . . only the interiors ofthe continents were spared. Rock from the crater, mixed with vaporized comet material, cooled Cel-- . to several thousand-degre- e sius as it rose in a fireball up as through the atmosphere the fireball reached the top ofthe atmosphere, it bobbed like a cork, floating on the cooler air beneath it, but it had nothing to hold it together and it began to spread out over the entire globe. As it spread its color cooled from a glowing red to an impenetrable black. The surviving creatures below probably thought that night had come early, but it was a night without a moon, without stars. The dinosaurs could not see their own claws in front of their faces. Morning would not come for several pionths. Nemesis the Death Star. Dr. Richard Muller. Daniel Cohen writes in his book Waitingfor the Apocalypse: . . . this much we can be certain ... MAKE SURE THE VISITOR TO KANAB KNOWS ABOUT YOUR BUSINESS.... With a brochure in the KIOSK in front of Glazier's Food Town! lrionp r r essviAe Gc fes olifu OV Att eAa ll ' Visitors to the area love these information kiosks. If you would like your business's brochure in the kiosk, call David H. Combs at Crystal Radio (101.9 FM) at -- Lake Powell Communications , r. ,.' XT ' jfmmimmi Vi ;1 '- -- - f ' the earth in the past, causing considerable damage, and large meteorites will continue to strike the earth from time to time in the future as long as the earth exists. Thousands of asteroids are traveling in orbits that cross the Earths orbit, but of those that have been found, none are on the verge of colliding with the Earth in the foreseeable future. The real danger is not discovering the objects that could crash into our Blue Orb and destroy life. A 1 Kilometer asteroid impact -- could cause the death of at least 25 of humankind, and such catastrophes can be expected about once every 100,000 years: Rogue Asteroids and Doomsday Comets. Duncam Steel, for most of us, its hard to imagine that such an impact would unleash more energy than the most powerful nuclear weapon ever exploded. civilization as we know it couldbe changed or even doomed within the lifetimes of our grandchildren by collision of Earth with a comet . . . Cosmic R. Chapman and David. Morrison. So, whats the answer? The first step is finding these Near Earth Objects (NEO) before they collide with Earth. That is hard to do since there are probably, more people working in your local McDonalds then there are patrolling the skies. The second step is to find amateur astronomers who are capable and have ample resources to do follow-uwork on these newly discovered space wanderers. The Lowell Observatory Near-Eart- h Object Search (LONEOS) is a system designed to find these vagabonds. AcBruce to Koehn, Recording search Scientist of Lowell Observatory in Flagstaff, AZ, newly discovered asteroids tend to become lost because their orbit is poorly known. It takes repeated observations over a timespan of years for an orbit to be well known, he says. The most critical time is the few days immediately following discovery. During this time an asteroid can be lost if it is not observed almost daily. After the first few days, the orbit is known well enough that observers can wait a week or two between observations. Koehn went on to say, If we had to follow-u- p everything we discovered, we would spend over half our time doing follow-up- . That means that half the time we would not be doing our primary task, which is discovery. Also there are times when we cannot do follow-u- p because of clouds or equipment failure. Catas-trophes-Cla- Earth-crossin- g Sto w V 20 of; large meteorites have struck t p : : wC v s J - changed by a few hundredths of a second . . Shock waves from the impact rattled the Earth with energy much greater than that of the Atlt0cl"res v'v 71 . ' rk Ed Sheridan at home in Johnson Canyon with one of his telescopes. Photo ' ' " by Barbara Pyles. . , Koehn said thats why amateur astronomers are so important. They can do follow-u- p observations that are difficult or impossible for the NASA-funde- d surveys (LONEOS, Spacewatch, d surNEAT) or Air veys (LINEAR) to do. Ed Sheridan, of Kanab, is one of those amateur astronomers who searches the sky, with computerized gear, doing follow-u- p work on fast moving objects. Sheridan says that each discovered asteroid requires several follow-u- p observations to determine its orbit. After Sheridan gets the coor: dinates from the Minor Planet, Centers (MPC) online service (MPC is the official clearing house for information on asteroids and comets), he goes to work. Force-funde- , - Sheridan peers through his 10 inch LX 200 Telescope, with CCD camera only long enough to locate a familiar star. He centers the telescope on the star, then sits at his computer and feeds in a point of reference. (The star being that point of reference). Next, he keys in the coordinates that tells the Schmidt-Cassegrai- n telescope where to point. Sheridan uses his computer to capture two images and software to perform the reductions. Then he compares the two photographs taken at different times with a Guide Star Catalogue, a map of the stars, from NASA on drive. I have the his on screen and the the picture CD-RO- M map. All I have to do is line up a few reference points, this allows me to pinpoint the exact loca- tion of the objects, says Sheridan. He explained . that Astronomy is a field where bad measures are generally of. no use. To be able to qualify for the program, you have to pinpoint an object in the sky down to the nearest .1 arcsecond, he says. In addition, Sheridan searches the entire screen in case there is something else out there. He sends, on line, his observations to the Minor Planet Center. Upon receipt, the MPC back an acknowledgment. Koehn gives an example ofhow Sheridan helped with an asteroid that was discovered on July 17: It looked interestingbecause was moving rapidly across the it . sky. (Fast motion indicates an asteroid that is near the Earth.) We asked several amateurs to do follow-u- p because there was no way we could see through the monsoon clouds that appeared that next evening, says Koehn. Ed was the only guy to find the asteroid.. He found it on the 19th of July. Because of his recovery, we were able to improve the orbit to the point where several other amateurs, including Ed, were able to locate it on the 25th. All these observations were good enough that the object could be connected to other observations of the object that were made in August of 1991. It turns out that LONEOS did not discover the object,, named 1991 PT9. But the recovery of the object, along with the follow-u- p observations performed by the amateurs, have now established an excellent orbit for the object. Its position is knbwn to within 0.01 degree for at least the next 10 years. There is no danger of 1991 PT9 getting lost again. Koehn says that 1991 PT9 is an asteroid that poses no danger to Earth. Its distance from the sun is slightly greater than Mars distance. Its orbit is highly inclined to the orbital plane of the planets. The high inclination is what makes it look like it is moving fast. What if there is a killer asteroid hurling toward Earth, with Earths name on it, then what? Are we prepared to fight back? With a few years of warning, some experts believe that a space mission could be mounted to shove it aside. Others arent so sure. ils . |