Three Billion-Year-Old Icy Spots On Moon Indicate Its Axis Shifted

Our moon probably rotated on a different axis about three billion years ago, after which the man on the moon turned up his nose at our good earth.

In a new study by planetary scientists at Texas' Southern Methodist University, volcanic action is seen as the reason for the shift, while NASA data showed data on lunar polar hydrogen. Orbital instruments picked up hydrogen and thought that ice was protected from the sun's heat by craters around the poles of the moon.

Matt Siegler headed the team that noted that ice boils off into space when open to direct sunlight. Ice noted by NASA is probably billions of years old, an indication of the moon's former direction.

A strange irregularity in the path from its current poles was detected by Siegler's team. Once they looked closer at NASA's Lunar Prospector and Lunar Reconnaissance Orbiter mission data, they performed statistical modeling and analysis, finding that the ice occurs in an offset pattern by the same distance at each pole, ie in opposite directions.

The identification of the "exact" opposite made them conclude that the axis of the moon has moved probably due to a change in its mass or perhaps because volcanic activity melted part of its mantle by a minimum of six degrees, probably more than one billion years ago, Siegler said.

"This was such a surprising discovery. We tend to think that objects in the sky have always been the way we view them, but in this case, the face that is so familiar to us - the Man on the Moon - changed," noted Siegler, who also works as a scientist at the Planetary Science Institute in Arizona.

"Billions of years ago, heating within the moon's interior caused the face we see to shift upward as the pole physically changed positions," he pointed out. "It would be as if Earth's axis relocated from Antarctica to Australia. As the pole moved, the Man on the Moon turned his nose up at the Earth."

The finding was published in the journal Nature.