Apollo 14 scientists may have brought back moon stones that turned out to be from Earth.
REPUBLIKA.CO.ID, JAKARTA — In 1971, astronaut Apollo 14 brought home various mineral and rock samples from their short trip to the Moon. For decades, rocks month it is still saved. These rocks are sometimes observed by researchers who want to try new techniques to learn more about lunar geochemistry.
Imagine the surprise of scientists who in 2019 discovered that these rocks came from land. The rock may be the oldest rock on Earth found so far.
This moonstone has quite the background. According to an international team of researchers, pieces of two grams of quartz, feldspar and zircon were found embedded in a larger rock called Big Bertha. This mineral combination should not be found on the Moon but is quite common on Earth.
Quartz and zircon are formed in oxidized systems such as Earth, in the high temperature and pressure environments experienced deep beneath the planet’s crust. Because zircon contains uranium, whose half-life is predictable, an international team of researchers can confidently date the rock to about four to 4.1 billion years ago, according to the Hadean Eon of Earth’s geological history.
They also determined, based on the geochemical properties of the sample, that it must have formed at a depth of about 20 km below the Earth’s surface. So how did it get to the Moon?
Reported from ZME Science, Tuesday (11/1/2022), the most plausible explanation is that a large asteroid impact threw these traveling minerals into space and eventually hit the Moon, Earth’s natural satellite.
For starters, the Moon was about three times closer to Earth than it is now. About four billion years ago, the planet was regularly bombarded by cosmic objects of all shapes and sizes, some of which are responsible for producing craters thousands of kilometers in diameter on Earth.