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About The Battalion. (College Station, Tex.) 1893-current | View Entire Issue (July 18, 1994)
Page 2 vmmmmmsmxmfflm HEALTH & SCIENCE •■ cs Monday* July 18, 1994 Monday Comet batters Jupiter Target: Jupiter Diameter: 88,730 miles Rotation: 9 hours 51 minutes Gravity: 2.69 times that of Earth Huge chunks of ice, rock from SL9 begin seven-day planet barrage Morning terminator Surface rotates into sunlight M ' ' f>*t* \ > \ GREENBELT, Md. (AP) — In a once-in-a-millenium spectacular, comet Shoemaker-Levy 9 is pummeling Jupiter with mountain-sized chunks of ice and rock, sending up towering fireballs and leaving black scars in the planetary clouds that may last for months. Fragments A, B, C and D of the 21-piece comet slammed into Jupiter Saturday and Sunday, repeated ly exploding into fireballs that extend for 600 miles above the cloud tops. The impacts are all behind Jupiter as viewed from Earth, but the bubbles of hot gases arising from each hit poke over the horizon and can be detected by large telescopes on Earth and by the Hubble Space Telescope. “The fireball extends beyond the limb (visible hori zon) of the planet,” Heidi Hammel of the Space Tele scope Science Institute said Sunday. She was speaking of a Hubble image taken of frag ment A’s explosion. “This is a massive thing,” she said. Fragment C, about the same 0.6 mile diameter as A, smashed Jupiter about 4:45 a.m. EDT, and infrared photos from the Keck Telescope in Hawaii showed two glowing scars, each about the diameter of the Earth. Fragment B is thought to have been much smaller and less compact. No images were released of that impact. Fragment D views are not expected to be ready until Monday. But more are coming. “This is just the orchestra warming up,” said David Levy, an amateur astronomer and a co-discoverer of the comet. Ahead are the largest four of the comet’s train of 21 pieces. Fragments G and H, which astronomers predict will hit on Monday, are both thought to be almost 2 miles across. Fragments K, expected to collide Tuesday, and Ql, which hits on Wednesday, are also about 2 miles in di ameter. The last fragment, called W, is forecast to hit on Friday. Names of the fragments don’t neatly follow the al phabet. Some fragments have disappeared, along i 1 with their letter designation. Q split apart, giving rise to two pieces with that letter. Scientists estimated that frag ment A released energy equiva lent to 10 million megatons of TNT when it slammed Jupiter at more than 130,000 miles per hour. Since the energy re lease increases geometrically, the larger fragments could have an explosive force of 10 times more. Fragment A left a black scar in the Jupiter cloud tops that some scientists said could last months, or perhaps as long as a year, despite the extreme currents that stir the planet’s stratosphere. The explosive force of the comets comes from their size and their extreme velocity. Eugene Shoemaker, U.S. Geo logical Survey astronomer and a co discoverer of the comet, along with his wife, Carolyn, and Levy, said tem peratures at the collision can reach tens of thousands of degrees. Jupiter is almost all hydrogen gas, with only a relatively small central core. But as a high-speed comet fragment strikes, it creates powerful shock waves in the upper atmosphere and probably punches through a layer of am monia clouds to a layer of dense hydrogen miles below. The shock waves create instant and extreme heat. Powerful forces of deceleration crush the comet fragments. “Huge clouds rumble up and create a plume,” said Levy. “That’s what we call a fireball.” ■ ^ »• Moons Jupiter’s 16 known satellites orbit the planet’s equator, and will not be hit by any of the 21 major comet fragments. c 0 Left to right: Ganymede, Callisto, to and Europa Limit of visibility Left of line is not visible from Earth i /L Impact zone All fragments strike on the night side of Jupiter, out of sight of Shoemaker-Levy 9 Looking for ringside seats View from Earth Jupiter Impacts are hidden behind planet. Astronomers will look anyway, to see if anything can be seen when impact point rotates into view a few minutes later. Hubble Space Telescope Earth. Impact areas rotate into view about 8 to 18 minutes later. Site rotates into sunlight 18 minutes after that. Earth to scale Great Red Spot Giant storm is about 16,000 miles across. AP illustration by Karl Tate The comet was drawn into orbit around Jupiter at some time in the past (probably around 1970-72). It was shattered into 21 pieces by Jupiter’s gravity in 1992. The train of fragments, currently more than 2.5 million miles long, is on course for smashing into the planet between July 16 and 22. Path of fragments View from Galileo Gets the best view of the impacts Jupiter appears about 60 pixels across in Galileo’s camera. Since the probe’s main antenna is not tu'} .fa l*ioW p arr’) “irt.r in „ Left of dotted tine: not-;, -: ) ■ , r ’ I - no a w t-n visible from Earth working, pictures will trickle back to Earth over backup antenna. Galileo space probe View from Voyager II Voyager ,11 is so far out, Jupjterwould, ^ajjpear only about two pixels across in its camera. Instead, other ‘inStrl/ntertis will be used to ‘ take measurements. Source: Paul Chodas and David Seal, Jet Propulsion Laboratory; Dan Bruton, Texas A&M University he; CHRI GOBI Guest I thoi con thrc not bel read, ground ing abo In J numbei in the s movie s Thes er with money women Let the Not 1 it is wi seem t sport at row wa‘ rings d< wrestle] they so smno-gc The i the spo take a p they me One of • wrestler is that t’ This: Wher make tl have doi require* was rec ceived a cone imp Yes, t is used passin then v have tl Tht turned dealinj cently. of silic he wo ment. The Co Human virus may render heart disease treatment inefFective WASHINGTON (AP) — Some blood vessels treated with coronary angioplas ty may become blocked again by a nat ural reaction, a new study suggests. The angioplasty treatment may be neutralized by the action of a common human virus against a gene that nor mally prevents the formation of cancers. Scientists at the National Institutes of Health report today in the journal Science that cytomegalovirus may de activate the cancer-defense gene and allow an overgrowth of smooth muscle cells inside arteries that have been opened by angioplasty, a procedure that uses an inserted balloon to clear clogged arteries. Earlier studies have identified the gene, called p53, as one of the body’s de fenses against cancer. Studies have shown that the gene’s normal function is to limit the growth of cells. Missing or deactivated p53 has been linked to many human cancers. Dr. Stephen E. Epstein, an NIH re searcher, said the study in his lab should be considered only preliminary and not proof that the cytomegalovirus, or CMV, is the culprit in closing the treated arteries. “We aren’t there yet (with proof),” he said, “but the evidence does suggest this as a possible mechanism for restenosis (the re-closing of arteries) after angioplasty.” However, Baylor College of Medicine virologist Dr. Joseph Melnick called the NIH study “fascinating” because it indi cates a possible link between cancer and heart disease. Patients with blocked arteries are treated with coronary angioplasty. In this procedure, a tube is threaded up an artery until it comes to a site that is blocked by a heart disease process. A collapsed balloon is then threaded up the tube and positioned at the block age. The balloon is inflated and com presses the plaque material that caused the blockage. This allows blood to flow freely. But in more than 25 percent of angio plasty patients, a blockage reforms at the treated site, often leading to the need for coronary artery bypass surgery. The NIH team reasoned that the new blockage may be caused by an uncon trolled growth of smooth muscle cells like those in the artery wall. Angioplas ty often causes a slight injury to the artery and the vessel then heals itself by growing new cells. It is possible, said Epstein, that the injury somehow activates CMV parti cles that are present, but latent, in the artery. This virus, he said, could at tach to p53 and then shut down the gene’s action. When p53 is deactivated, said Ep stein, smooth muscle cells repairing the artery are allowed to grow without re straint, forming a new blockage. “There are a lot of theories about what causes this restenosis and ours is just one of them,” said Epstein. Q Cause heat stroke, the most dangerous of the heat-related illnesses. Symptoms include an inability to sweat, increased body temperature, dizziness, fainting and loss of consciousness. Get help immediately. Remove as much of the victim’s clothing as possible. Sponge the skin with cool, not cold, water. Do not force liquid if victim is unconscious. Health Tips Fitness fanatics beware obsessive regimens By Lori Kuykendall A.P. Beutel Health Center Qj Cause heat exhaustion, the most common heat-related illness. Symptoms include clammy or sweaty skin, normal or slightly elevated temperature, rapid pulse, nausea and thirst. Get out of the heat and rest. Restore fluids by drinking slowly. Gently apply wet towels to the body. Check with doctors to see if salt or medication is needed. £1 Cause heat cramps, the least serious of heat-related illnesses that untreated can lead to more serious problems. Heat cramps usually occur after exercise or physical labor. Symptoms include sweaty skin, weakness or nausea, tingling in the arms and legs. ^ Get out of the heat and rest. Drink cool liquids. Check with a physician to see if salt or medication is needed. Cooling off; D Reduce physical activity E When outside, stay in shade or wear wide-brimmed hat or use umbrella. E Use air conditioners or fans or go to places that have them. E Bathe or shower in cool water. E Drink plenty of liquids. Avoid alcohol, coffee and tea or other drinks that cause fluid loss. E Do not take salt tablets. APAVm. J. Gastello Many Texas A&M students are putting much of their time and energy into getting and maintaining the “perfect body.” Look in any of the local gyms from about 4 p.m. until midnight or watch all the peo ple who are making no-fat or low-fat choic es for meals and snacks. As a young, well-educated population, college students are generally considered one of the healthiest segments of our nation. Unfortunately, many students are be coming overly concerned about health and body image. Their drive to be healthy goes too far. The result can be compulsiveness and ob session, which in turn can lead to a dangerous eating disorder or other emotional problems. It is easy to gradually acquire a miscon ception of the difference between health and thinness. Often a desire to become healthy be comes a desire to be too thin. Such a crossover from health to exces sive eating and exercise can occur for many reasons. Going away to college gives students a chance to become who they want to be and exercise new independence. A student wants to get a new body image and be a new person. People trying to lose weight should do so moderately over time....They should not drop below 1200 calories a day. It is encouraging to be able to go home for the holidays and have people give com pliments about losing weight or having a new “college image.” Another cause of an over-obsession with body image can be perfectionism. Often overachievers struggle with an ex treme drive for perfection in academic areas, outside activities, and eating and exercising. The danger comes when the balance shifts from being “healthy” to being overly con cerned and discontented about body image. Any health textbook will define health as a balance of physical, mental, social, spiritu al and emotional well-being. It is important to reach and maintain a weight that will heighten physical health, but it is equally important to attain emotion al well-being. Part of being healthy is accepting nat ural body size. Most people cannot have extremely thin bodies. There will always be people smaller than, and a lot of people bigger than, some one else. The key to a healthy diet is moderation. Health professionals on not recommend ex treme dieting and starvation as a healthy way to lose weight. A healthy diet is low in fat and consists of food from the five food groups in the food guide pyramid. People trying to lose weight should do so moderately over time, making permanent lifestyle changes. They should not drop be low 1,200 calories a day. an econo States w hind in Japan, 1 athletes cept. Can 3 athletes Every six inche in the so] Footb; room to jections i Let’s 1 our cour places w] the injed WILLIAM L ANAS BEN- SUSAN OV MICHELE B The Batta spring sei holidays Station, T POSTMA A&M Un News: Tl Division 013 Reec Advertisi Battalion advertisi r a.m. to 5 Subscripl year. To