The Contribution of Small Impact Craters to Lunar Polar Wander
Name
Smith_2022_Planet._Sci._J._3_217.pdf
Description
Published version
Size
6 MB
Format
Adobe PDF
Checksum (MD5)
8d394926fd0d677d2a6d7afe3ed72ec8
Author(s)
Smith, David E
Viswanathan, Vishnu
Mazarico, Erwan
Goossens, Sander
Head, James W
Neumann, Gregory A
Zuber, Maria T
Date Issued
2022
Journal
The Planetary Science Journal
Publisher
American Astronomical Society
Citation
Smith, David E, Viswanathan, Vishnu, Mazarico, Erwan, Goossens, Sander, Head, James W et al. 2022. "The Contribution of Small Impact Craters to Lunar Polar Wander." The Planetary Science Journal, 3 (9).
Version
Final published version
Abstract
Abstract
Changes in mass distribution affect the gravitational figure and reorient a planetary body’s surface with respect to its rotational axis. The mass anomalies in the present-day lunar gravity field can reveal how the figure and pole position have evolved over the Moon’s history. By examining sequentially each individual crater and basin, working backward in time order through the catalog of nearly 5200 craters and basins between 1200 and 20 km in diameter, we investigate their contribution to the lunar gravitational figure and reconstruct the evolution of the pole position by extracting their gravitational signatures from the present-day Moon. We find that craters and basins in this diameter range, which excludes South Pole–Aitken, have contributed to nearly 25% of the present-day power from the Moon’s degree-2 gravitational figure and resulted in a total displacement of the Moon’s pole by ∼10° along the Earth–Moon tidal axis over the past ∼4.25 billion years. This also implies that the geographical location of the Moon’s rotational pole has not moved since ∼3.8 Ga by more than ∼2° in latitude owing to impacts, and this has implications for the long-term stability of volatiles in the polar regions.
Changes in mass distribution affect the gravitational figure and reorient a planetary body’s surface with respect to its rotational axis. The mass anomalies in the present-day lunar gravity field can reveal how the figure and pole position have evolved over the Moon’s history. By examining sequentially each individual crater and basin, working backward in time order through the catalog of nearly 5200 craters and basins between 1200 and 20 km in diameter, we investigate their contribution to the lunar gravitational figure and reconstruct the evolution of the pole position by extracting their gravitational signatures from the present-day Moon. We find that craters and basins in this diameter range, which excludes South Pole–Aitken, have contributed to nearly 25% of the present-day power from the Moon’s degree-2 gravitational figure and resulted in a total displacement of the Moon’s pole by ∼10° along the Earth–Moon tidal axis over the past ∼4.25 billion years. This also implies that the geographical location of the Moon’s rotational pole has not moved since ∼3.8 Ga by more than ∼2° in latitude owing to impacts, and this has implications for the long-term stability of volatiles in the polar regions.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.3847/PSJ/AC8C39
