Ever looked up and wondered about all of those dark spots on the Moon? Join us with Michelle, as she discusses her primary interest—lunar craters and where they are found! These craters are created by asteroids and meteors hitting the surface on the Moon over time, and little is known about the bombardment history of the Moon after the Late Heavy Bombardment (~ 3.8 Billion years ago) until today—the Moon's "Middle Ages."
Using the concentration of small craters (about 1-km diameter) placed over images of the floors of larger craters (at least 50-km diameter), scientists have been determining when the larger craters formed. These ages are helping them to fill in the blanks in the history of the Moon's "Middle Ages." Results seem to be hinting that there may be time periods of relatively few impacts separated by periods of heavier bombardment. This pattern may be related to recent break-ups of large asteroids to produce "families" in the Asteroid Belt.