Question

Astronomers can use the numbers of craters on different parts of the same world to provide important clues about how regions on that world evolved. On a given planet or moon, the more heavily cratered terrain will generally be

Answer 1

Astronomers determine the age of planetary regions by examining the number of craters, with more craters usually indicating older terrain. Earth's active geology and atmosphere erase craters over time, contrasting with the Moon's well-preserved impact history due to its airless surface.

Step-by-step explanation:

Astronomers analyze crater numbers on planets and moons to determine the age of various regions. Heavily cratered surfaces usually indicate older terrain, as it has been exposed to space debris for an extended period. Factors like volcanic activity and plate tectonics can modify or erase craters, just as snow can be cleared from a sidewalk. Lack of an atmosphere, geological activity, or a thick atmosphere influences the preservation of impact craters. For example, Earth's active geology and atmosphere lead to the erasure of craters, while the Moon's airless surface preserves its impact history more completely.

The comparison of cratered surfaces across different worlds, like the Moon and Mercury, provides a window into the history of the solar system. By examining craters, astronomers can estimate how long it has been since a surface was last 'swept clean' and gain insight into the evolution of the planetary system.