Mars may have relics of baby planets beneath its crust. Researchers have found two unique materials on the planet that never mixed, suggesting they came from different sources.
The new study, published in Nature Geoscience, originally aimed to understand how the Red Planet’s crust lost light hydrogen like its atmosphere. Researchers analyzed two meteorites sent into space by ancient impacts on Mars and crash-landed on Earth.
“We weren’t even planning to test that whole thing,” Jessica Barnes, a cosmochemist at the University of Arizona, said. “But it was the results that we got from the crust that made us have to go back and kind of look at that hypothesis.”
One meteorite named Black Beauty dated back to 4.4 billion years ago, a few years after Mars formed. The other space rock appears nearly four billion years old, Popular Science reported.
Both Martian rocks have signs of exposure to hydrogen. Barnes said finding the meteorites were wet before they came to Earth gives “a fairly large piece of Mars’s history.”
Reconstructing the history of the two rocks, the researchers found that two forms of hydrogen remained unchanged in the crust of Mars unlike the atmosphere. The planet’s interior potentially remains frozen or crystallized.
The researchers then analyzed other hydrogen measurements of samples of Martian rocks from the crust to confirm the initial findings. They looked into lava rocks that came from two different locations in Mars’s mantle.
Modeling shows that the two classes of rocks had a hydrogen ratio similar to that of the meteorites. That means there is strong evidence that within Mars are two types of rock left over from small planets mashed together but never mixed well.
Researchers plan to continue the study and create simulations of the young Mars to see how deep the baby planets mixed. Barnes will also collect a wider range of Martian rocks to confirm their initial findings.
“We’re going [to] continue analyzing new samples and analyzing other meteorites,” Barnes said. “There’s plenty of work to do.”
The team hopes the study would guide future efforts to understand how all planets in the solar system formed.