The Geologic Time Scale is up there with the Periodic Table of Elements as one of those iconic, almost talismanic scientific charts.Long before I understood what any of it meant, I'd daydream in science class, staring at this chart, sounding out the names, wondering what those black-and-white bars meant, wondering what the colors meant, wondering why the divisions were so uneven, knowing it represented some kind of deep, meaningful, systematic organization of scientific knowledge, and hoping I'd have it all figured out one day.These data fall on a well-defined line indicating a crystallization age for the anorthosites of 4.46 billion years, consistent with very early, widespread melting of the Moon. Chondritic meteorites have revealed an impressive portrait of conditions in the early nebula (see articles Dating the Earliest Solids in our Solar System and The First Rock in the Solar System), whereas igneous meteorites such as the eucrites provide a glimpse of what the early planets may have looked like (see article Asteroidal Lava Flows).Other data for 67215 show that it comes from a relatively shallow depth in the crust, giving us clues to the structure of the lunar crust. The compositions and textures of eucritic meteorites show that some asteroids were extensively molten, and it would not be surprising if similar processes occurred on the early planets."We can see cratered terrains on the Moon whose ages we don't know within a billion years," says Dr. "Ages of lunar terrains are the linchpin for understanding the sequence of planetary-scale events from Mercury to Mars, so filling this gap in our understanding of the Moon will help us correct or re-write the history of volcanism, planetary evolution, water, and life in the Solar System." Dating the Duluth Gabbro was approximately 30 times more analytically challenging than our previous experiment, dating the Martian meteorite Zagami, noted co-author Dr. "We are now continuing to analyze planetary samples of increasing complexity," he said.The researchers have proposed to NASA to send a dating mission to the Moon called MARE: Moon Age and Regolith Explorer.
Many of the techniques used to date rocks on Earth are not practical in spaceflight, but a technique called laser ablation resonance ionization mass spectrometry can avoid the need for sophisticated sample preparation. Their results, published in Rapid Communications in Mass Spectrometry, imply that events from Solar System history that are recorded on much of the visible face of the Moon can one day be dated directly by instruments aboard a lunar lander.
Although researchers have determined the ages of rocks from other planetary bodies, the actual experiments -- like analyzing meteorites and moon rocks -- have always been done on Earth. Water found in ancient Moon rocks might have actually originated from the proto-Earth and even survived the Moon-forming event.
Scientists have studied the amount of water within lunar rocks returned ...
Scientists determined the Earth's age using a technique called radiometric dating.
Radiometric dating is based upon the fact that some forms of chemical elements are radioactive, which was discovered in 1896 by Henri Becquerel and his assistants, Marie and Pierre Curie.
A few days ago, I wrote a post about the basins of the Moon -- a result of a trip down a rabbit hole of book research.