Scientists have long wondered why it is that the moon isn’t a simple sphere and new research has identified early tidal forces as a likely cause for the irregularity.
Scientists have long wondered why it is that the moon isn’t a simple sphere. Concrete explanations for its somewhat bulging shape have been elusive.
New research has identified early tidal forces as a likely cause for the irregularity.
In a published paper, the authors say that when the moon was forming some 4 billion years ago there was a period of time when it was quite malleable as it was liquid rock.
As it was hardening, it was also subjected to both tidal and gravitational forces.
This caused the then-soft satellite to bulge and dip in some places, and at some point they were solidified.
If this theory sounds familiar, it’s because it was originally proposed in the late 1800s, but had some evidence problems.
In rebooting the idea, the recent researchers included more tidal activities and other possible factors.
Among them were the moon’s proximity to Earth and crater impact basins.
Needless to say, it was a complicated process and factoring in for certain topographical anomalies was tough. Said one of the authors, "We did a lot of work to estimate the uncertainties in the analysis that result from those gaps."