Despite being our closest neighbor, scientists have been struggling to solve the mystery of our moon’s origin for hundreds of years.

From in the 1980sexperts hypothesized that our lunar satellite formed after an explosive collision with the protoplanet Theia early in Earth’s history. But now, a study shows that this so-called “conflict” theory may not be correct after all.

Instead, researchers from Penn State University say the Earth could have tightly hooked the moon, pulling it along in a process called binary-exchange capture (binary exchange concept).

This radical theory suggests that the moon may have started as part of a “terrestrial binary,” a pair of rocky objects orbiting each other.

As this pair passed through Earth’s pull, the moon was put into orbit while the second body was launched into space.

Lead researcher Professor Darren Williams says: “No one knows how the moon was formedi. For the past four decades, we’ve been considering a hypothesis about how it got there. Now, we look at two».

In 1984, scientists gathered for the Kona Conference in Hawaii to reach a consensus on how the moon had formed.

Using the 800 pounds (363 kg) of lunar material taken back from NASA’s Apollo missions, scientists discovered that the moon had a similar, but not quite identical, chemical composition to Earth.

From this evidence, they concluded that the moon must have formed from debris lost when a celestial body struck the young Earth.

This theory was popular because it fits well with much of what we now know about the moon’s chemical composition—but it doesn’t explain all the details.

For example, Professor Williams and his co-author point out that if the moon formed from a ring of debris slowly condensing into a sphere, we should expect to find it orbiting above the equator.

However, the moon’s orbit is actually about seven degrees away from the equatorial plane.

To find an alternative explanation as to why this might be happening, the researchers looked at a phenomenon called binary-exchange capture.

This suggests that Earth may have grabbed a pair of passing rocky bodies and turned them into its satellite.