PHYS 3510 Lecture Notes - Lecture 3: Late Heavy Bombardment, Rosetta (Spacecraft), Plate Tectonics
Document Summary
It must be older than the oldest minerals found on. It must be older than the oldest moon rocks (4. 4 gyr old) We know that the moon formed after the earth. It must be younger than the oldest meteorites (4. 57 gyr old) Scientists now estimate that the earth is about 4. 54 gyr old. Note: you will be expected to remember the eons and eras shown here. How it is maintained (earth"s built-in thermostat) The moon is thought to have formed very soon after the earth formed. It is thought to have formed as the result of the impact of a mars-sized object. While the impact rate was generally higher further into the past, there is evidence for an increased rate of impacts roughly 3. 8-4. 1 gyr ago. This is called the late heavy bombardment. This may have been caused by rapid migration of the. The interior of earth has several important effects on the surface.
