AST 101 Lecture Notes - Lecture 10: Radiation Zone, Nuclear Fission, Nuclear Power
Document Summary
Leftover planetesimals bombarded other objects in the late states of solar system formation. Large planetesimal obliterated, then accreted into the moon. Giant collision between mars-sized object & the earth. Giant impacts might also explain the different rotation direction of. Venus and uranus, and the extreme tilt of uranus" axis. Uranus" moons and rings are also tilted relative to the. Suggests that the protoplanetary was already tilted as moons formed. Recent computer simulations shown that gravity perturbations during the early history of the solar system are enough to tilt uranus over. We can"t find the age of a planet, but we can find ages of rocks that make it up. We can determine age of rock through careful analysis of proportions of various. Radioactive decay: atoms and isotopes within it. Half-life: time for half the nuclei in a substance to decay. 6. 9 x 10^8 meters (109 times earth) Solar system is about 4. 6 billion years old.
