The moon has always been a source of mystery and awe, for scientists and laypeople alike.

Which is probably why everyone is curious about the radioactive rock found on the far side of our favorite floating rock.

And this newly discovered rock formation is big. In fact, it’s over 30 miles in diameter.

The rocks are actually a large formation of granite and exist right under the lunar surface. Researchers say in their coinciding paper that they hope it could offer some clues about the Moon’s history.

Study co-author Matthew Siegler, a SMU professor, says it suggests that the far side of the moon was once home to at least a few volcanoes that would have erupted around 3.5 billion years ago.

“Any big body of granite that we find on Earth used to feed a big bunch of volcanoes.”

The rock deposits left behind are typically much bigger than the volcanoes they used to feed above the surface.

“For example, the Sierra Nevada mountains are a batholith, left from a volcanic chain in the western United States that existed long ago.”

Researchers used microwave frequencies to determine the makeup of the radioactive rocks, and deduced that the radioactive elements it contained could only belong to granite.

The deposit of granite was found in a region called the Compton-Belkovich anomaly, and measures over 30 miles in diameter.

“The surprising magnitude and geographic extent of this feature imply an Earth-like, evolved granitic system larger than believed possible on the Moon.”

As with most scientific findings, this leaves us with at least as many new questions as answers.

“If you don’t have water it takes extreme situations to make granite. So, here’s this system with no water, and no plate tectonics – but you have granite. Was there water on the moon – at least in this one spot? Or was it just especially hot?”

Rest assured that they intend to find out.

So, stay tuned.