AST101H1 Lecture Notes - International Astronomical Union, Astronomical Unit
10 May 2012
School
Department
Course
Professor
23
AST101H1 Full Course Notes
Verified Note
23 documents
Document Summary
All assignments due tuesday at 11:59 pm. The solar system is huge and the vast majority of it is empty (tiny quantities of gas and dust fill the space) 1 au (distance between sun and earth) = 1 astronomical unit. (mercury is 0. 4 au, venus is 0. 7 au, mars is 1. 5 au) = 1 astronomical unit = 1. 5 x 1011m. = average distance between earth and the sun light year is measure of distance (distance light travels in a year) Sun and nearest start 4. 4 light years. = distance light travels in one year light travels at a finite speed. 1 au = 8 light minutes (for light to get from earth to sun) So, no matter where you look, you are looking back in time. The andromeda galaxy is 2. 5 million ly away. It"s the nearest large galaxy to the milky way. The galaxy ngc 4696 is about 150 million light years away.
