New research indicates that the moon may have been turned on its side in an ancient space collision.
Scientists believe that our moon, which contains signs of activity including volcanoes and a frozen magnetic field, formed when a planet about the size of Mars crashed into Earth long ago, reported. The theory is that the early Earth and our moon were left in a molten state after the collision, giving the moon a core that would generate a magnetic field.
Examining magnetic data from the orbiters Lunar Prospector and Kaguya, a team of Japanese researchers analyzed 57 sites on the moon to estimate the orientation of its magnetic field during different periods.
"We find that the north poles, as well as the antipodal south poles, cluster in two distinct locations: one near the present rotation axis and the other at mid-latitude," the scientists wrote. "The clustering is consistent with a dipole-dominated magnetic field generated in the lunar core by a dynamo that was reversing, much like that of Earth."
While the Earth's magnetic pole has gradually migrated over time, the magnetic field on the moon seems to have been adjusted suddenly at one point. Publishing their findings in the journal , the authors hypothesized that the change could have been caused by a collision or a gravitational disturbance.
As reported by Ars Technica, an earlier 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.