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back to earth

Lunar Samples of Apollo 11 & 12 1972 NASA color sound 10min

2mo ago
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video for embedding at http://scitech.quickfound.net/ "Apollo 11 carried the first geologic samples from the Moon back to Earth. In all, astronauts collected 22 kilograms of material, including 50 rocks, samples of the fine-grained lunar "soil," and two core tubes that included material from up to 13 centimeters below the Moon's surface. These samples contain no water and provide no evidence for living organisms at any time in the Moon's history. Two main types of rocks, basalts and breccias, were found at the Apollo 11 landing site. "Basalts are rocks solidified from molten lava. On Earth, basalts are a common type of volcanic rock and are found in places such as Hawai'i. Basalts are generally dark gray in color; when one looks at the Moon in the night sky, the dark areas are basalt. The basalts found at the Apollo 11 landing site are generally similar to basalts on Earth and are composed primarily of the minerals pyroxene and plagioclase. One difference is that the Apollo 11 basalts contain much more of the element titanium than is usually found in basalts on Earth. The basalts found at the Apollo 11 landing site range in age from 3.6 to 3.9 billion years and were formed from at least two chemically different magma sources. "Breccias are rocks that are composed of fragments of older rocks. Over its long history, the Moon has been bombarded by countless meteorites. These impacts have broken many rocks up into small fragments. The heat and pressure of such impacts sometimes fuses small rock fragments into new rocks, called breccias. Many fragments can be seen in the breccia photograph shown above. The rock fragments in a breccia can include both mare basalts as well as material from the lunar highlands. The lunar highlands are primarily a light-colored rock known as anorthosite, which consists primarily of the mineral plagioclase. It is very rare to find rocks on Earth that are virtually pure plagioclase. On the Moon, it is believed that the anorthosite layer in the highland crust formed very early in the Moon's history when much of the Moon's outer layers were molten. This stage in lunar history is known as the magma ocean. The plagioclase-rich anorthosite floated on the magma ocean like icebergs in the Earth's oceans." http://www.lpi.usra.edu/lunar/missions/apollo/apollo_11/samples/ "When viewed through a telescope, the Apollo 12 landing site has fewer craters and a slightly redder color than the Apollo 11 landing site. It was thought that these characteristics indicated that the rocks at the Apollo 12 landing site were both younger and different in chemical composition than the rocks at the Apollo 11 landing site. Apollo 12 returned 34 kilograms of samples, including 45 rocks, samples of lunar "soil," and several core tubes that included material from as much as 40 centimeters below the lunar surface. This material both confirmed the pre-mission expectations and also posed some new questions. "The Apollo 11 rocks were a mixture of basalts and breccias. In contrast, the Apollo 12 rocks were almost all basalts, with only two breccias in the returned samples. Basalts are dark-colored rocks solidified from molten lava. They are a common type of volcanic rock on Earth and are found in places such as Hawai'i. The basalts at the Apollo 12 site formed 3.1 to 3.3 billion years ago, roughly 500 million years later than the Apollo 11 basalts. Basalt consists primarily of the minerals pyroxene and plagioclase. At the Apollo 12 landing site, several different varieties of basalt were identified from the presence of other minerals such as olivine or ilmenite. Overall, there is much less of the element titanium in the Apollo 12 samples than in the Apollo 11 samples, which explains the more reddish color of this region. The differences in age and chemical composition between the Apollo 11 and Apollo 12 samples demonstrate that mare volcanism did not occur as a single, Moon-wide melting event. The Apollo 12 basalts formed from mate...