Imagine the Moon not as a cold gray world, but as a scorching hell where the entire surface boils and volcanoes rage. New scientific data suggests that this could have been the early history of our moon, which resembled a volcanically active body in the Solar System — Jupiter’s moon Io.
Research presented by planetary scientist Francis Nimmo of the University of California, Santa Cruz, offers a revolutionary perspective. They suggest that tens of millions of years after its formation, the Moon underwent an incredibly intense volcanic period. The surface of the moon has been repeatedly flooded by lava, which has erased old craters and concealed its true geological age.
Gravity swing
After the giant collision with Theia, which gave rise to Earth and the Moon, our moon was significantly closer. But initially, its orbit was not stable. The gravitational opposition between the Sun and Earth pulled the Moon into a kind of “tug-of-war.” This chaos had catastrophic consequences for the Moon’s interior. Gravitational “mixing” heated its interior, melting rocks and creating huge layers of magma that broke through to the surface.
Models show that around 4.35 billion years ago, the surface of the Moon may have been literally melted by powerful lava flows. These flows would have filled all existing craters, effectively resetting the geological clock. This explains why measurements of the age of lunar rocks and zircon crystals give this relatively “young” date, even though the Moon is older — about 4.5 billion years.
Mystery of age
Determining the exact age of the Moon is no easy task. Scientists use two main methods: analysis of lunar rocks and zircon dating. Both methods often indicate 4.35 billion years. A new study by Nimmo and colleagues, published in Nature, provides a clue to the mystery: intense melting during the volcanic period may have recrystallized the rocks and zircons, “rejuvenating” them and masking the true age of the Moon.
Lunar volcanism
Although volcanism was extremely active, it looked different than on our planet. Earth’s volcanoes build cones from thick, silicate-rich lava. On the Moon, however, the lava was probably more liquid and fluid. It seeped through cracks in the crust, forming huge lava flows rather than high mountains.
“There was certainly a lot of volcanism there, but it didn’t create volcanoes as we know them,” Nimmo emphasizes. This constant seepage may have prevented the formation of a deep magmatic ocean, as the melt quickly rose to the surface or filled cavities in the crust.
Amazing view from early Earth
At that time, the Earth was much closer to the Moon and appeared twice as large in its sky as it does today. The scene was apocalyptic: “You would see molten lava flowing everywhere and perhaps strange eruptions,” Nimmo imagines. This fiery phase, similar to modern Io, lasted “only” a few tens of millions of years, but left a deep mark on the Moon’s geological memory.
“It was a short but very intense period,” summarizes the scientist, opening a new, dynamic page in the life of our natural satellite.
Earlier, we reported on how a dubious theory about the formation of the Moon was confirmed experimentally.
According to LiveScience
