Credit: University of Chicago
Thanks to lunar material returned to Earth by Apollo moonwalkers decades ago, new research suggests how the Moon was formed.
There has been a widely held theory that a giant collision between Earth and a Mars-sized object gave birth to the moon 4.5 billion years ago.
Not so, explains a science team led by Junjun Zhang at the University of Chicago. Their work indicates the Moon’s material came from Earth alone.
In a form of “planetary DNA,” the researchers have studied meteorites, which are pieces of asteroids that have fallen to Earth, and contain large variations in titanium isotopes. Measurements of terrestrial and Apollo lunar samples show that the Moon has a strictly identical isotopic composition to the Earth.
“We thought that the Moon had two parents, but when we look at the composition of the Moon, it looks like it has only one parent,” Zhang said.
“We thought we knew what the moon was made of and how it formed, but even 40 years after Apollo, there is still a lot of science to do with those samples that are in curatorial facilities at NASA,” explains researcher Nicolas Dauphas, Associate Professor in the Department of the Geophysical Sciences, Enrico Fermi Institute, at The University of Chicago.
The research findings have been published in Nature Geoscience. Funding for the work was provided by NASA, the National Science Foundation, Packard Foundation and the Swiss National Science Foundation.
By Leonard David