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Show EEE __TheSalt Lake Tribune SCIENCE Thursday, December 3, 1998 Mars Probe Already DazzlingScientist With ImagesIt Is Sending Home NEWSDAY As the Mars Global Surveyor spacecraftslips closer and closertoits assigned orbit, scientists find their plates are already overflowing with exciting data, stuff they have barely beenabletotaste. muchless digest. Even before the big spacecraftsettles into its circular path aroundthe red planet, the new photos it is sending home are forcing researchers to rethink some older ideas. For example: Although Mars was known to be a windy place, the new evidence suggests it is windier yet, sc the terrain is probably more rapidly remodeled than expected. Layeredterrain seen nearthe red plan- et’s poles consists of more layers, and thinner, than expected. This indicates episodes of climatic change occur more often than anticipated. Instead of epi- sodeslasting millions of years, they occur at intervals at least 10 times shorter. A few huge valleys seem to have smaller channels erodedinto their floors. This is important because such features are similar to valleys seen on Earth. Thus similar processes — think water — may be involved in creating them For thefirst time, evidence showsthat massive flowsoffluid lava solidified into hugeflat plates, which then cracked into smaller chunks and floated around on still-molten lava below. tively recently in Mars’ history,” £ northern lowlands. What's visible now arelarge dark plates separated by inter- can missions. Thescientists noted that other images plate-like terrain in a nearbybasin, MarteVallis, which implies that someof thehot lavarolling over Elysium veningbright are: “Somescientists thought they could somehow be volcanic, while others thought they might be related to differences in the way the wind eroded a dried lakebed,” said Alfred McEwen, a member of the science team from the Univer- Basin spilled into the other valley and rolled on for thousands of miles to the northeast Because few meteorite impact craters arevisible on the lava plates, the scien tists reasonthat the lava flows occurred late in the planet's life. after the major The new, clearer photos of Mars’ E um Basin showthat the hardened stretches for hundreds of miles acrossthe sity of Arizona he added, “it is now quite easyto understandthe older lower-resolution Viking images” that weretaken in 1976 by two earlier AmeriWith these new images. show simil:lar voleanoes such as Olympus Monshadfin ished erupting “The sparse occurrenceof i act craters ontheseplate-like lava su gests that the eruptions happened rela younger than the youngest of the larg Martian volcanoes. but they would sti have occurred many, many millions years ago. So these images should not treated as evidence that Marsis volear cally active today What is active today, according to th latest photos, are the wind-blown sar dunes, which are certainly migratin across the Martian surface. Obvior changes in the dunes have occurred two decades between the Viking missi and the arrival of the new spacecraft Global Surveyor Because of the newdata, “it's beeomin clear that Marsis a much more comple» planet than seemed to be indicated by th Viking coverage,” said planetary As Transplant For Leukemia NEWS SERVICE FORT LAUDERDALE, Fla. — Bone-marrow transplants, heralded for 15 years as the best hope for many leukemiapatients, work no better than less costly chemotherapy, a University of Miamistudyhas found. The transplants proved better than chemoat beating leukemia into remission — helping patients live longer — buttheyalso caused complications that killed more patients prematurely, said the study in today’s issue of the New England Journal of Medicine. It wasthe lead article in the publication. The results surprised the study’s author, Peter Cassileth. whocalled himself a proponentof transplants. “Previous studies in this area showed [transplant therapy] was better,” Cassileth said. “I still think it has value.” A Welsh cancer expert who wrote an editorial accompanying the study said techniques are in the works to identify in advance patients who would dobetter with transplants and those who would do worse. That would improve the 9.99 successrate. The study's findings suggest chemoshould replace transplants as the first treatment given to most patients. Transplants worked much better in killing leukemia among chemotherapy patients who had a relapse, and would be best used in that way, Cassileth said, or $39.95 For 1020 Minutes For 600 Minutes 20 anytime minutes It's a better chance of saving them,” Cassileth said. 300 anytime minutes + a 1000 off peak minutes 300 off peak Minutes The transplanttreatmentis rigorous. Doctors use chemoor radiation to kill all the body’s bone or marrow to wipe out the cancer, then attempt to regrow it by transplanting bone marrow and Get the Airtouchdigital Traveler. 50 States. No Roaming similar stem cells, both of which can restock the body’s red blood cells and immunecells. Transplants have been used on certain leukemia patients since the early 1980s, at a time when only a quarter of chemo patients were cured. As much as 60 percent of transplant patients are Foraslittle as cured, Chemo drugs cure about 70 percentof lenkemiapatients, and the cost is a third or less of the transplants, which start at $70,000. $59, 95 for 450 minutes Study Explains Evidenceof Tropical Glaciers @ Continued from A-1 Coverage you can count on. nism is right. Harvard researcher Paul Hoff- man, who recently reported on evidence indicating glaciers killed off almost all life during the same period, said Kasting’s explanation is possible, but he supports thesocalled snowball Earth scenario to explain the existence of glaciers in the tropics. Under the snowball scenario, glaciers crept toward the equator from the poles, and eventually melted. Richard Peltier, a professor of physics at the University of To- ronto who studies changes in the motion of the Earth, said the mechanism proposed by the Penn State researchers was not ex- plained in enoughdetail But he said he’s “not so skepti- cal to say it’s totally unreason- able. 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