Ancient Moon Rock May Originate From Earth
Nearly half a century after it was discovered, scientists are now beginning to think that a rock sample gleaned during an Apollo mission to the moon actually came from Earth. According to them, the rock originated from our planet around four billion years ago.
Starting with our first venture to the moon with Apollo 11 and ending with the latest Apollo 17 mission, astronauts visiting the iconic satellite have been given many different tasks over the years. One of them was to collect a variety of rocks to bring back home for dating and analysis.
The team of researchers publicized their findings in the Earth and Planetary Science Letters journal, and reportedly used new technology to learn more about a 2-gram moon rock sample collected by Apollo 14 astronauts in the early 1970s. Their findings have since suggested that, instead of the rock having originated from the moon, it actually came from Earth many, many years ago.
Scientists Peg Sample as Felsite
The scientists believe that the special rock is a sample of felsite, which is composed of quartz, feldspar and small amounts of zircon. It is similar in texture to granite, which is the kind of rock that forms our continents. Researchers think that felsite is produced through plate tectonics – that is, the shifting of Earth’s outer crust.
The study’s findings have hinted that the best explanation for the rock type’s existence on the moon is that it is not from the moon at all. Considering that we know how it is created on Earth, our best guess now is that it originates from our own planet too.
A chemical analysis of the rock has revealed that it is also crystallized. The scientists have suggested that conditions on our planet just more than 20km below the surface between 4 and 4.1 billion years ago may have prompted this process. According to co-author David Kring, the specimen came as confirmation that they had found something granitic, and that there were large enough impact events to launch objects from Earth in the past.
Impacts Launched Rock to the Moon
The principal investigator at the Center for Lunar Science and Exploration at the Lunar and Planetary Institute also says that it is amazing that the rock managed to survive. The reason for him saying this was that the particular sample “underwent three significant impacts”.
The solar system, Kring says, was filled with large bodies that were flying about as planets and moons were busy forming. At this time, Earth was believed to have been blasted with interplanetary debris.
Shortly after the formation of Earth, many large bodies like asteroids or comets slammed into its surface, displacing rock and launching it into space. Some of this rock clearly reached the surface of the moon, which is understandable when you consider that it would have been 2.8 times closer to our planet then than it was today!