Perlu buat Fluid Inclussion analysis.... Siapa tau ada minyaknya juga. -----Original Message----- From: Awang Satyana [mailto:[EMAIL PROTECTED] Sent: 10 March 2004 09:37 To: [EMAIL PROTECTED] Subject: [iagi-net-l] Indikasi Positif Air Pernah Ada di Mars (?)
Geologists akan punya banyak PR dari oleh-oleh Opportunity rover di Mars. Salam, Awang Opportunity rover finds further evidence of wet martian past. 4 March 2004 NASA's Mars lander Opportunity has found minerals and rock formations that help to prove that the planet was once very wet. "Liquid water once drenched the surface of Meridiani Planum," says Ed Weiler, NASA's associate administrator for space science. "It would have been habitable for some time," he says. The flat plain of Opportunity's landing site covers an area roughly twice the size of Lake Superior. Scientists are still unclear whether the whole area was once a giant lake, or whether the minerals they have found were simply soaked in ground water that percolated up through the rock. The evidence comes from the analysis of a rocky outcrop called El Capitan, found near Opportunity's landing site, says Steven Squyres, principal investigator on the project. A whole lot of sulphur Opportunity first found that the dust on this rock's surface is rich in sulphur. This confirms evidence seen by the Viking 2 lander in 1976. But Opportunity was able to use infrared measurements to go one step further, showing that much of it is in the form of sulphate ions - a key component of common salts that are usually formed in water. "You'd need a lot of water to have the massive amounts of sulphur we see here," says Squyres. Upper parts of the rock were found to contain up to 40% sulphate. Lower parts of the rock were found to be rich in bromide ions, which are more soluble in water than sulphate. This is clear evidence of an 'evaporitic sequence', says Benton Clark, chief space scientist at Lockheed Martin Space Systems at Denver, Colorado. As a pond of salty water evaporates, it leaves behind different minerals at different times. Less-soluble minerals precipitate out first, and more soluble minerals only appear as most of the water disappears. Washed away Opportunity also looked at small spherical blobs found encased in the rock. Researchers did not know at first whether these globules were formed by water, or if they were droplets of glass spat out by volcanoes or a meteorite impact. If the latter, then researchers would expect the blobs to appear in layers in the soil. Pictures taken by Opportunity show that they aren't in layers, suggesting that they were instead formed when minerals precipitated from bubbles of liquid water trapped inside the rock. The craft also took close-up photographs of the rocks showing strange holes that are long, thin and tapered towards the ends. The NASA team believes that these were left behind when crystals were washed away by flowing water. "They look exactly like the holes left by gypsum crystals on Earth," says John Grotzinger, a geologist with the rover science team. Opportunity's next challenge is a rock nicknamed Big Bend, where it will study the rock's layers that may have formed by sedimentation. After that, Opportunity could set out for a 30 metre-deep crater that may expose very old material from Mars's past, says project scientist Joy Crisp. But the crater is more than 600 metres away. "Our rovers might not last that long but we'd like to try," she says. "The next big challenge is to return pieces of Mars to Earth," says Jim Garvin, a Mars scientist at NASA. We need to get some of these rocks back to our labs to work out how long ago there was water on Mars, says Squyres. © Nature News Service / Macmillan Magazines Ltd 2004 --------------------------------- Do you Yahoo!? Yahoo! Search - Find what you're looking for faster. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] Visit IAGI Website: http://iagi.or.id IAGI-net Archive 1: http://www.mail-archive.com/iagi-net%40iagi.or.id/ IAGI-net Archive 2: http://groups.yahoo.com/group/iagi Komisi Sedimentologi (FOSI) : F. Hasan Sidi([EMAIL PROTECTED])-http://fosi.iagi.or.id Komisi SDM/Pendidikan : Edy Sunardi([EMAIL PROTECTED]) Komisi Karst : Hanang Samodra([EMAIL PROTECTED]) Komisi Sertifikasi : M. Suryowibowo([EMAIL PROTECTED]) Komisi OTODA : Ridwan Djamaluddin([EMAIL PROTECTED] atau [EMAIL PROTECTED]), Arif Zardi Dahlius([EMAIL PROTECTED]) Komisi Database Geologi : Aria A. Mulhadiono([EMAIL PROTECTED]) ---------------------------------------------------------------------
