Scientists may have just found the oldest intact Earth rock-on the moon.
Analysis of the rock showed that it contained 2 grams of a fragment that was composed of three very common materials found on Earth: quartz, feldspar, and zircon.
While moon rocks have been recorded ending up on Earth as a result of asteroid impacts, the reverse had not previously been observed.
What could be Earth's oldest rock was found almost 50 years ago, but it wasn't found on this planet.
Nemchin is quick to point out that he and his team are not 100 percent certain that the sample originated on Earth although the evidence would suggest that.
This rock, along with other lunar samples, was lying at the Lunar Curation Facility at the Johnson Space Center in the United States.
An ancient rock believed to be one of the Earth's oldest was found by astronauts on the moon and brought it back to our planet.More news: Title of new Ted Bundy movie derives from Miami judge's statement
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Yes, this supposed moon rock is actually an Earth rock.
The rock is considered a relic of an intense period of bombardment that shaped the solar system during its first billion years, after which the moon was only affected by small and less frequent events.
The evidence gathered by the team shows that this fragment formed 4.1 - 4 billion years ago at nearly 20 km under Earth's surface.
And it is only now that researchers chose to take a closer look at the "unusual" rock that was brought back the Apollo 14 crew.
That impact resurfaced the rock, which was then collected by the Nasa astronauts. After the rock came to rest on the lunar surface, another impact 3.9bn years ago partially melted and buried it, scientists believe. At an estimated four billion to 4.1 billion years old, the terrestrial zircon mineral found in the sample is now among the oldest known to exist.
The team from Curtin University in Western Australia were studying samples collected by the 1971 Apollo 14 lunar mission on loan from NASA, in association with researchers from the Swedish Museum of Natural History, Australian National University and Lunar and Planetary Institute in Houston.
The authors of the new study presented two possibilities to explain the anomalous sample: Either it formed on Earth (very likely) or it formed deep within the Moon (highly unlikely). However, conditions at no other time gathered from lunar examples would be required along with an example, in the lunar mantle, to have framed at huge profundities where many other rocks were combined together. Scientists have discovered the rock decades ago by the Apollo 14 crew.
The theory that the moon was once a part of Earth and was cast off by a massive cosmic collision is not new, but recent findings show that, strangely, a piece of Earth may have managed to find its way to the moon after this event.