Scientists think they have figured out why the Moon is made up of such weird and heavy rocks on its surface.
For decades now, scientific consensus is that the Moon formed from debris that flew off the young Earth when another planet smashed into it about 4.5 billion years. That cosmic wreckage "coalesced, cooled and solidified" to form the Moon as we know it today, say researchers from the University of Arizona's Lunar and Planetary Laboratory (LPL). But what happened next is surprising.
In a new paper published in the journal Nature Geoscience, the LPL researchers found that the surprisingly high concentration of titanium found in Moon rocks, such as those brought back during the Apollo mission in the 1970s, could be the result of heavy minerals like ilmenite, which is rich in both titanium and iron, initially sinking to the core (where you would expect them to stay) and then, for reasons still unknown, rising back up to the surface. It's proving to be a bit of a head-scratcher for scientists.
"Our moon literally turned itself inside out," declared LPL associate professor and paper co-author Jeff Andrews-Hanna.
"Our analyses show that the models and data are telling one remarkably consistent story," explained Weigang Liang, the leader of the research and principal author. "When the Artemis astronauts eventually land on the Moon to begin a new era of human exploration, we will have a very different understanding of our neighbor than we did when the Apollo astronauts first set foot on it."