Tag: 青浦桑拿

Lunar rock samples reveal variations in water concentrations

first_img Citation: Lunar rock samples reveal variations in water concentrations (2014, May 26) retrieved 18 August 2019 from https://phys.org/news/2014-05-lunar-samples-reveal-variations.html (Phys.org) —A team of researchers studying rocks returned from the moon by Apollo 17 astronauts has found that rocks found in different locations have different amounts of water in them. In their paper published in the journal Nature Geoscience, the team describes their findings and offer possible explanations for the concentration differences. Secondary electron image of pits left by ion microprobe analyses of a heterogeneous apatite grain in Apollo sample 14321, 1047. Water has now been detected in apatite in many different lunar rock types. Credit: K.L. Robinson, HIGP. Optical micrograph of pyroclastic glass beads in Apollo sample 74220, 383, the famous “orange soil”. Water was first detected by Saal et al., 2008 in glass beads similar to these. Credit: G.J. Taylor, HIGP More information: Heterogeneous distribution of water in the Moon, Nature Geoscience (2014) DOI: 10.1038/ngeo2173AbstractInitial analyses of lunar samples returned by the Apollo missions indicated that the Moon was essentially devoid of water. However, improved analytical techniques have revealed that pyroclastic glass beads in Apollo samples contain measurable amounts of water. Taking into account volatile loss during eruption of the glass beads onto the surface, the pre-eruption magma could have contained water on the order of 100 ppm by weight, concentrations that are similar to the mantle sources of mid-ocean ridge basalts on Earth. Lava flows from vast basaltic plains—the lunar maria—also contain appreciable amounts of water, as shown by analyses of apatite in mare basalt samples. In contrast, apatite in most non-mare rocks contains much less water than the mare basalts and glass beads. The hydrogen isotopic composition of lunar samples is relatively similar to that of the Earth’s interior, but the deuterium to hydrogen ratios obtained from lunar samples seem to have a larger range than found in Earth’s mantle. Thus, measurements of water concentration and hydrogen isotopic composition suggest that water is heterogeneously distributed in the Moon and varies in isotopic composition. The variability in the Moon’s water may reflect heterogeneity in accretion processes, redistribution during differentiation or later additions by volatile-rich impactors. Explore further © 2014 Phys.org Digging deep in search of water on the moon Journal information: Nature Geoscience It was just six years ago that scientists learned that there was water on the moon, prior to that, conventional wisdom suggested the moon was not only barren, but completely dry. That discovery led to more research which revealed that not only is there water on the moon, but it’s actually widespread—sealed inside of rocks, but present nonetheless. In this new effort, the research team reports that in studying the findings of several other teams analyzing the rocks since water was first found in them, they’ve discovered that some of the rocks have more water sealed inside of them than others—the difference appears to be related to where on the moon the rocks were found. This suggests, the team reports, that some parts of the moon are wetter than others. The new research team also found that the chemical composition of the water was different depending on the rock source as well.The findings have led the researchers to consider how differing water concentrations relate to theories regarding the origin of the moon. Most scientists believe the moon came to exist approximately four and half billion years ago when a collision occurred between Earth and another planet. The general consensus is that some of the moon came from Earth, some from the other planet and the rest from other bodies such as comets and asteroids that subsequently struck the moon. Water on the moon could therefore have come from the Earth, the other planet or comets. Intriguingly, the researchers have found that the chemical makeup of water samples in some of the rocks (volcanic glass) is similar to magma samples that once resided in Earth’s mantle. Others, on the other hand, were found to be much drier. The researchers conclude that the formation of the moon appears to have been a far more complex series of events than theories have suggested. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Read more…

Columbia University Names George Rupp as New President

first_imgShare Contact: Michael Berryhill Phone: (713) 527-4943 Columbia University Names George Rupp as New President Rice University president George Rupp was named president of Columbia University, Columbia officials announcedMonday in New York. Rupp, 50, will be Columbia’s 18th president, replacing Michael I. Sovern, who announced last summer he was stepping down from thepost for personal reasons. Rupp announced in November he would leave Rice at the end of the fiscal year, June 30. His decision to leave the university was designed “to allow an immediate search for my successor,” he said atthe time. In response to Columbia’s announcement, Charles Duncan, chairman of Rice’s board of governors, issued a statement saying:”President Rupp’s administration has left an indelible stamp onthe university. The number and the quality of faculty haveincreased. The students, who are applying in increasing numbers, arebetter than ever. Rice has added two major buildings, one for musicand one for bioscience and bioengineering, and both have beennationally recognized for their excellence. These improvements andmany others were achieved during the administration of PresidentRupp.”This momentum built is not going to be lost. The board will continue to work with all members of the university community during the next several months while Rice looks for a new president. The search to find a successor for George Rupp is proceeding smoothly under the direction of [board of governors member] Kent Anderson and the search committee comprised of members of the board of governors, alumni, students, faculty and staff.” Rice Provost Neal Lane praised Rupp’s tenure in office.”George Rupp has, by any measure, been a truly outstandingpresident,” Lane said. “By providing strong intellectual leadership,enhancing the quality of the faculty, staff, students and programs,strengthening interdisciplinary education and research, improvingteaching and research facilities and emphasizing outreach, he hasmade this excellent university even better.”The faculty, staff and students greatly appreciate what President Rupp has done for Rice, and, I know, wish him well in his new challenge.” Columbia’s 238-year-old campus is located in New York City. The school has 2,300 full-time faculty members and 19,900 students. ### FacebookTwitterPrintEmailAddThislast_img read more

Read more…