Earth has fewer impact craters than Mercury due to the following reasons:
1. Destruction of meteorites in Earth's upper atmosphere: Earth's atmosphere is thicker compared to Mercury's, which causes most small meteoroids to burn up before reaching the surface. This phenomenon helps protect Earth from impacts, resulting in fewer visible craters.
2. Slower weathering and erosion rates on Earth: Earth's active geological processes like weathering, erosion, and plate tectonics gradually erase the evidence of impact craters over time. This ongoing process, combined with factors like vegetation growth and water flow, contribute to the reduction in visible impact craters on Earth.
3. Faster rotational speed of Mercury: Mercury rotates much slower than Earth, meaning that any impact craters on its surface are less likely to be eroded or covered by geological processes. The slower rotation of Mercury allows impact craters to remain more visible and preserved over time compared to Earth.
