Tilt of Moon's Axis May Explain the Origin of Water on Earth

A recent research paper published in the journal Nature said that the tilt of the Moon's axis shifted over billions of years ago, and their findings may help explain the origin of water on earth.

Scientists have long speculated on the most probable origin of the water on earth, whether it originated from ancient bombardments of asteroids and comets, or from the matter that formed the planet some 4.5 billion years ago.

In this study led by Dr. Matthew Siegler, the researchers studied hydrogen distribution, mainly in the form of frozen water. The team mapped the distribution of ice on the moon using the data gathered by orbiting neutron spectrometers.

Analyses of the data and previous lunar studies revealed that certain shadowed areas inside craters near the poles do not have sufficient ice water. Others have strange distribution.

Based on these findings, it was inferred that the moon has changed the tilt of its axis over time.

Planets and other massive objects in the solar system can change their tilts due to several reasons. These include gravitational influence from other more massive objects in space, collisions or asteroid bombardments and internal shift in the distribution of mass.

The internal shift may be caused by the melting and then solidifying of materials in the interior as the result of geologic interactions. In their work, Siegler and his team discovered that the only area that matches the shift is the Procellarium region.

The said region has sufficient radioactive material that could have heated and melted the mantle from above, thereby triggering a shift in the mass.

Compared to earth, the water distribution on the surface of the moon is generally preserved over billions of years because of the latter's lack of atmosphere and significant geologic activities. Comparing the water on the moon with the water found in asteroids and comets could lead to clearer understanding of how Earth was able to acquire its water.

Mapping the water distribution on the moon also opens a possibility of governments and private entities to colonizing the moon in the future or use it as the launching base for further space explorations.