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| Titel |
Major Elements Abundances in Chang'E-3 Landing Site from Active Particle-induced X-ray Spectrometer |
| VerfasserIn |
Xiaoping Zhang, Minggang Xie, Meng-Hua Zhu, Wudong Dong, Zesheng Tang, Aoao Xu |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101563
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| Publikation (Nr.) |
 EGU/EGU2015-726.pdf |
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| Zusammenfassung |
| Chang’E-3, China’s first Moon lander and rover mission, was launched at 17:30 on 1st
December 2013 (UTC) and successfully landed on Moon surface at 13:11 on 14th December
2013 (UTC). About 8 hours later after the soft landing, the rover, named "Yutu” after
a mythological rabbit that lives on the Moon as a pet of the Moon goddess, was
successfully separated from the lander and started its adventure on the Moon. The success
of this mission marks the first soft-landing on the Moon since 1976. The landing
site is in northern Mare Imbrium (N44.12, W19.51), close to the boundary of two
different geologic units and sits on “young” Eratoshenian lava flows which spread
several hundreds to thousands of kilometers. The mare basalts in the landing site
are believed to be formed from the lava flows ~2.5 billion years ago, which are
significantly younger than all of the returned lunar samples, dating from 3.1 to 3.8
billion years ago. This makes the landing site a very interesting place for exploring
geochemical characteristics of the young lava flows and lunar evolution in a later
stage.
ÂÂActive Particle-induced X-ray Spectrometer (APXS) is the only payload on the
robotic arm of Yutu rover. It was designed to measure the intensities of characteristic
fluorescent X-rays produced by interactions of lunar sample with incident X-rays.
Major elements abundances of Mg, Al, Si, Ca, Ti, Fe on the lunar surface were
expected to be detected after the exploration. On December 24th (UTC), 2013 and
January 14th (UTC), 2014, APXS performed 4 successful measurements on lunar
soils along Yutu’s track. Characteristic peaks of Mg, Al, Si, K, Ca, Ti, Cr, Mn, Fe,
Ni, Cu, Sr and Zr could be clearly seen from the measured spectra. A global fit
based on minimum chi-square method has been performed to disentangle different
components in the measured spectra. These components include Kα and/or Kβ
peaks of each element, escape peaks, exponential and shelf tail of major peaks and
electronic noises, etc. Fundamental parameter method has been used to extract the
absolute abundances based on the measured spectra of soil samples and the calibration
targets.
ÂÂPreliminary results show that one measured soil sample contains 10.7 wt. % MgO, 10.5 wt.
% Al2O3, 42.5 wt. % SiO2, 0.13 wt. % K2O, 10.5 wt. % CaO, 4.0 wt. % TiO2, and 20.7 wt.
% FeO. In the Fe-Ti correlation plot, the FeO and TiO2 concentrations mark a new region that
is never discovered in previous in-situ detection of lunar regolith samples. However, it sits
well on the trend established from the remote sensing data by gamma ray spectroscopy of
Lunar Prospector. Al2O3 and magnesium number (0.48) correlation manifests the
characteristics of young materials. In summary, chemical elements abundances in the landing
site suggest a kind of young mare basalt which appears to have unusual petrological
characteristics. |
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