Scientists Claim a Violent Collision Knocked the Moon on its Side

The Moon was once rocked by a violent collision that eventually led to the tilt in its present orientation, according to new research published in the journal Nature Geoscience.

Scientists believe that our Moon, which contains signs of activity including volcanoes on its surface and strong magnetic fields frozen in its rocks, formed when a Mars-sized body collided with an ancient Earth, Ars Technica reported.

The theory is that this event left both orbs in a molten state, giving the Moon a molten core that would generate a magnetic field.

Analyzing magnetic data from the lunar orbiters Lunar Prospector and Kaguya (placed at altitudes as low as 40 kilometers from the surface), a team of Japanese researchers looked at 57 sites on the Moon to estimate the orientation of its magnetic field during different previous periods of time.

The data suggests a change in the axis of rotation. One set of data indicates the Moon's current pole, but the second data cluster suggests a shift somewhere between 45 degrees to 60 degrees, compared to the existing pole.

While the Earth's magnetic pole has gradually migrated over time, the magnetic field on the Moon seems to have jumped abruptly.

"A change in the apparent pole position corresponds to a reorientation of the lunar surface with respect to the rotation axis," the authors added.

The researchers hypothesize that the change could have been caused by giant impacts, internal instabilities or a gravitational disturbance by other planets in the solar system.

This isn't the first time scientists have thought the Moon has shifted its orientation. As reported by Ars Technica, an earlier study also indicated that the Moon's orientation was shifted in an ancient impact, citing the number and placement of craters on the orb's surface.

There is sufficient evidence to grant further exploration into the theory, but so far neither of the methods of tracking this shift have been precise enough to indicate when this event might have taken place.