* Orbital Period: Mercury has a much shorter orbital period than Earth, orbiting the Sun in just 88 days. Earth takes 365 days. This means Mercury experiences sunrise and sunset much faster.
* Rotation Period: Mercury's rotation period is also slower than its orbital period, meaning one "day" on Mercury is equivalent to about 59 Earth days. This means that while Mercury experiences a full cycle of day and night, the change in shadow length is spread out over a much longer time.
The combined effect of these factors leads to much faster changes in shadow length on Mercury compared to Earth. Imagine a time-lapse of shadows on both planets. Mercury's shadows would be whipping back and forth much more rapidly than Earth's, creating a dramatic visual difference.
