NATS 1740 Lecture Notes - Lecture 13: Seismic Wave, Outer Core, Planetesimal

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Tatiana Paulin

Document Summary

Mantle: between the crust and core, composed of dense rock. Seismic waves: used to study the internal structure of earth. Differentiation: the seperation of each planets material into layers according to density. Cratering and giant basin formation: could not begin until a solid surface formed. Slow surface evolutioin: has continued for at least the past 3. 5 billion years. Maria: lunar lowlands lled by successive ows of dark lava, very low albedo. Albedo: the ratio of the amount of light re ected from an object to the amount of light recieved by the object. Highlands: heavily cratered, lighter-coloured regions, composed of low-density rock, older than maria (eg. anorthosite, many rocks found on the moon are breccias. Three hypotheses developed to explain the origin of the moon failed when all evidence was compared. The ssion hypothesis: the moon broke off from a rapidly spinning proto earth.