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Clocks in the Rocks

RADIOMETRIC DATING OF ROCKS

Skip to content Skip to navigation. The scientific rationale for lunar exploration is to establish the Moon's composition, internal structure, and history or evolution. Before man walked on the Moon, scientists thought that the Moon was a relatively primitive simple object that would record the earliest history of the Solar System. More than 50 U. A total of 24 U. During 80 hours of surface activities, the astronauts carefully collected kg of lunar samples see sample inventory on table 1.

Mare basalts come in three distinct series in direct relation to their titanium content: high-Ti basaltslow-Ti basaltsand Very Low-Ti VLT basalts. Almost all lunar rocks are depleted in volatiles and are completely lacking in hydrated minerals common in Earth rocks.

In some regards, lunar rocks are closely related to Earth's rocks in their isotopic composition of the element oxygen. The Apollo Moon rocks were collected using a variety of tools, including hammersrakesscoopstongsand core tubes.

Most were photographed prior to collection to record the condition in which they were found. They were placed inside sample bags and then a Special Environmental Sample Container for return to the Earth to protect them from contamination.

Our Cratered Moon: This composite image of the Moon's surface was made . most important tasks was to bring back lunar rocks for radioactive age-dating. Exploration Science Department include Antarctic Meteorites, Moon Rocks from history of the Moon by careful radiometric age dating of lunar samples (fig. Lead isochrons are also an important radioactive dating process. Note that uranium and uranium give rise to two of Dating of meteorites, Moon rocks.

In contrast to the Earth, large portions of the lunar crust appear to be composed of rocks with high concentrations of the mineral anorthite. The mare basalts have relatively high iron values.

Dating The Moon

Furthermore, some of the mare basalts have very high levels of titanium in the form of ilmenite. Primary igneous rocks in the lunar highlands compose three distinct groups: the ferroan anorthosite suite, the magnesian suite, and the alkali suite. Lunar breccias, formed largely by the immense basin-forming impacts, are dominantly composed of highland lithologies because most mare basalts post-date basin formation and largely fill these impact basins.

Mare basalts are named as such because they frequently constitute large portions of the lunar maria. These typically contain percent FeO by weight, and percent TiO 2. They are similar to terrestrial basalts, but have many important differences; for example, mare basalts show a large negative europium anomaly. The type location is Mare Crisium sampled by Luna Johnson Space Center in Houston, Texas. Most of the rocks are stored in nitrogen to keep them free of moisture.

They are handled only indirectly, using special tools. Some Moon rocks from the Apollo missions are displayed in museums, and a few allow visitors to touch them.

Moon rocks collected during the course of lunar exploration are currently considered priceless.

Naturally transported Moon rocks in the form of lunar meteorites are sold and traded among private collectors. Apollo 17 astronauts Eugene Cernan and Harrison Schmitt picked up a rock "composed of many fragments, of many sizes, and many shapes, probably from all parts of the Moon". This rock was later labeled sample The fragments were presented encased in an acrylic sphere, mounted on a wood plaque which included the recipients' flag which had also flown aboard Apollo Three minerals were discovered from the Moon: armalcolitetranquillityiteand pyroxferroite.

How Carbon Dating Works

Armalcolite was named for the three astronauts on the Apollo 11 mission: Arm strongAl drin and Col lins. Because of their rarity on Earth, and the difficulty of obtaining more, Moon rocks have been frequent targets of theft and vandalismand many have gone missing or were stolen.

Lunar Ferroan Anorthosite Plagioclase Feldspar. Sample collection case, containing collection bags for use on the surface, at the National Museum of Natural History. Cut fragment of Apollo 17 samplean impact melt breccia.

Apollo 16's samplebetter known as Big Muleyis the largest sample collected during the Apollo program.

Big Berthacollected on Apollo 14is among the largest rock samples returned from the Moon nearly 9 kilograms. From Wikipedia, the free encyclopedia.

For other uses, see Moonrock. Rock from the Moon. Main article: Geology of the Moon.

Main article: Lunar sample displays. Main article: Stolen and missing Moon rocks. Samplethe Seatbelt basalt.

Solar System portal. Archived from the original on 25 August Retrieved 13 October A total of kilograms of lunar material, comprising individual specimens returned from the Moon, has been processed to meet scientific requirements into more thanindividually cataloged samples. The drill was deployed and penetrated to a depth of 35 cm before encountering hard rock or large fragments of rock. The column of regolith in the drill tube was then transferred to the soil sample container Meteoritical Bulletin Database.

The Meteoritical Society. Retrieved 20 July More than 50 U. A total of 24 U.

During 80 hours of surface activities, the astronauts carefully collected kg of lunar samples see sample inventory on table 1. In addition to the samples gathered from the six Apollo U. Many exotic samples in the Apollo collection come from rays that extend as much as halfway around the Moon fig. Recently, numerous meteorites found in Antarctica and the Sahara desert have been shown to have originated on the Moon Korotev Figure 1.

Scientists computed the age of the Apollo 11 moon rocks times using older than 6, years, so the radiometric ages still prove the Earth is old. Grenville Turner, “Argon/Argon Dating of Lunar Rock Samples” pages

The Moon is divided into two basic physiographic regions: smooth maria and cratered highlands. The smooth maria fill the large circular basins and spill out onto low lying regions.

Radiometric dating of lunar rocks

They were sampled by Apollo 11, 12, 15 and 17 and Luna 16 and The ejecta blankets of the large basins were sampled by Apollo 14, 15 and The heavily cratered highlands were sampled by Apollo 16 and Luna Note the great distances covered by rays from fresh craters. NASA photo no. The scientific objectives and results of each Apollo mission are summarized in table 2. From these missions, we learned that the Moon is not the simple, primitive object we once thought it to be, but, rather, a satellite that has been melted and differentiated twice in its history.

The first melting occurred shortly after formation and apparently resulted in a Moon-wide magma ocean that cooled to form a thick crust of anorthositic material.

The moon's age has remained the subject of debate due to discrepancies in the radiometric dates obtained on earth and moon rocks. When you have an element with a known rate of radioactive decay, you can back -calculate a time for when collected moon rocks were formed. Rocks from the Moon have been measured by radiometric dating techniques. They range in age from about billion years old for the.

While cooling to form a solid body, parts of the interior melted again to form lava flows on the front side. The heat for the first melting comes from the terminal accretion; the heat for the second melting comes from the radioactive decay of K, U and Th in the interior. Much of this heat is brought to the surface with the extruded magma. Carefully refined computer models are now available with which to illustrate the thermal evolution of many planetary bodies, including that of the Earth.

From our study of lunar and meteorite samples, we have learned that different planets and moons have different chemical and isotopic signatures. For example, meteorites can be distinguished from samples of the Earth and the Moon by their high Ir and Au contents.

Small extraterrestrial samples have high He and D 2H contents. Using such signatures, scientists have shown that several meteorites found on the ice in Antarctica are actually lunar samples Bogard A clay layer found at the Cretaceous-Tertiary boundary has been identified as having an extraterrestrial cause.

Tektites, once thought to have come from the Moon, have proven to be of terrestrial origin. Can chemical signatures like these be used to tell whether we have samples of other planets in meteorite collections? We have discovered the bombardment history of the Moon by careful radiometric age dating of lunar samples fig. A surprising result was that most of the samples from the lunar highlands gave the same age; i.

This indicates that the Moon and perhaps other planets as well was subjected to an intensive period of bombardment late in its evolutionary history. The lack of intense cratering on the mare surface, which has been dated to as great an age as million years, means that this intense bombardment ended suddenly a cataclysm. However, there appears to be no record of this cataclysmic bombardment in meteorites.

Lunar Sample Science Today

Can we deduce from this the age of heavily cratered terrain either on Mars or Mercury? Figure 2. Impact breccias from the rims of large basins and the lunar highlands, all dated million years.

Radiometric dating of complex Moon breccias. In the case of the Moon, there are two major sources of rocks for dating. Most samples studied by scientists. Moon Rocks Reveal That We Were Very Wrong About The Age of The Moon able to accurately date the age of the Moon in the past is that there's very Since uranium - a radioactive element - eventually turns into lead after. This suggested age makes the Moon a lot older than some recent Zircon has already been found to be a valuable tool for dating rocks here on Earth. Uranium is a radioactive element that converts into lead over a long.

This has been termed the lunar cataclysm. Clasts of pristine lunar plutonic rocks are older. Mare basalts have ages spanning million years. A few breccias are younger e. A search for the oldest lunar rock is still ongoing but the identification of the most ancient sample has remained elusive see Table 5 in the section of Plutonic Rocks.

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