ASTRON 2B03 Lecture 4: Astron 2BO3 Lecture 4
18 Mar 2016
School
Department
Course
Professor
Document Summary
What"s the diff bw a planet and a dwarf planet? (why did pluto get demoted) Has not cleared the neighbourhood of its orbit. Some planets are rocky like the earth and some are made of gas like jupiter. Average temp on the surface is about 5500k. Makes up about 99. 8% of the mass of our solar system: most the rest is jupiter and saturn. 4. 5 billion years old and is expected to shine for another 5 billion years. As the sun gets older, it gets brighter and hotter and bigger. In a few billion years the sun will be so hot it will burn away life on earth. The sun revolves around our galaxy (the milky way) every 225-250 million years. Going from interplanetary space to interstellar space is a huge jump in the distance. Average distances between stars are about a million times larger than the distances between the planets in our solar system.
