The Moon is Earth’s most reliable companion in space, having orbited our Earth for 4.5 billion years—almost as long as our planet has existed. But a new analysis of crystals from the Moon’s surface shows that the satellite may be older than previously thought.
The Moon is thought to have formed when the early Earth collided with a Mars-size protoplanet, an event that occurred about 4.35 billion years ago based on rocks in the lunar surface. Pinning the timeline of the Moon’s evolution doesn’t just guide us through the history of that rocky place—it helps planetary scientists understand the evolution of our Earth and the larger solar system.
Now, a team of researchers says that while estimates of the Moon’s age are between 4.35 billion and 4.51 billion years old, the younger date indicates a different dynamical event of “early recrystallization of the lunar magma ocean,” as they write in a paper published today in The environment.
The total number of rocks that are 4.35 billion years old suggested to the team that due to a widespread remodeling event, the actual age of the Moon was also slightly older. Researchers deduced the age from zircon crystals from the lunar surface, found by the Apollo missions. Although the rest of the moon underwent remelt, some of the crystals near the surface did not, thus preserving an authentic record of the Moon’s age.
The team notes that the Moon is probably no older than 4.53 billion years old, “the earliest time when basic formation may have ended.” The first time the Moon could have formed, the researchers say, was about 180 million years before the later heating event on the satellite. In other words, if the part of the moon we know and love is the result of a melting event, and the Moon is older than thought, it is not. extremely older than thought.
In the paper, the team said that “current models do not support the idea that impacts were responsible for the reset event,” although the jury remains out on what could have caused such widespread melting of the moon. The researchers say the melting may have been “Moon orbital driven”—in other words, the gravitational pull on the Moon by bodies like Earth and the Sun.
Earlier this year, a study published in Environmental science he concluded that the Moon may have evolved over several million years to form. The new paper also complicates the story of the origin of our long-term partner in the solar orbit.
We still have a long way to go in space exploration, though the Artemis mission—which will return humanity to the Moon for the first time in decades—will be an important step toward understanding the origins of our rocky satellite.
Source link
