Related Experiment Video
Updated: Jul 12, 2026

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
Mercury's Rotation Period: Photographic Confirmation
Abstract:
Photographic measures of surface features on Mercury have led to a rotation period of 58.663 +/- 0.021 days, which is in good agreement with the 58.646-day period required by a predicted 2:3 resonance between the axial and orbital periods. The incorrect interpretation of earlier visual and photographic observations which supported an 88-day rotation period appears to be partially explained by peculiar characteristics associated with the observability of various hermo-graphic longitudes. The apparent contrast of most of the recorded surface features is marginal for visual observation when viewed through the terrestrial daytime sky. The intrinsic contrast of a relatively conspicuous feature was measured as 0.20, a value lower than that of typical markings observed on the moon and Mars.
Related Concept Videos
Simple Harmonic Motion and Uniform Circular Motion
There is an easy way to produce simple harmonic motion by using uniform circular motion. For instance, consider a ball attached to a uniformly rotating...
Gyroscope: Precession
Magnetic Declination
Rotational Motion about a Fixed Axis
Atomic Nuclei: Larmor Precession Frequency
Apparent Weight and the Earth's Rotation
For an object on the Earth's equator, the net centripetal force that accounts for its rotation is the Earth's pull towards its center, or the weight minus the normal force that prevents it from piercing into the Earth's surface. This force,...

