BIO 200LLB Lecture Notes - Lecture 2: Precambrian, Protoplanetary Disk, Hadean

• School: University at Buffalo
• Department: Biological Sciences
• Course: BIO 200LLB
• Professor: J. Poulin

Document Summary

Protoplanetary disk- roatating cloud of dust, rock, and gas. A star close to the protoplanetary disk destroyed itself in a supernova. The explosion sent a shockwave through the disk and it began to accelerate. The center of the disk begins to concentrate and heat up. Pressure within the central mass of the protoplanetary disk triggers nuclear fission. Protoplanet- perturbations outside of the outer rings caused by the explosion. Gravity outside the reach of the sun causes matter to condense aro und protoplanets and it starts to separate into rings which eventually lead to planets. Earth formed around 4. 5 billion years ago. During the earliest parts of hadean era (bombardment of matter) Fully molten, no oceans, no oxygen, and no protective atmosphere. During the end of the hadean era the earth is cooling. Asteroids caused cracks on the new surface and steam begins to escape which combined with gas, started to form the. Clouds and rain eventually give rise to oceans.