ASTR 1101 Midterm: Astronomy 1101 Test 1
Document Summary
1 year = 365. 24 days: scientific notation, 1=1x10^0, 1700= 1. 7x10^3, 0. 1=10^ 1, 0. 045=4. 5x10^ 2, units in space, astronomical unit (au) average distance between the sun and the earth. 1 ly = 9. 46x10^12km: = 63000au or 6. 3x10^4au, =0. 307 parsecs (pc, when to use what, km distances on or near earth, au solar system distance, mly between galaxies (millions of ly, ly between planets, gly across the universe (billions of ly) Lecture two observations and ancient greek astronomy: philosophical ideas, the heavens represent perfection, the heavens are immutable (unchanging, the circle is the perfect shape, ptolemy, wrote the almagest, made a model based on greek ideals, earth was at center did not move, everything goes around the earth, stars are all fixed in the celestial sphere, star movement, rise in the east/ set in the west, circumpolar stars that appear to circle around the north or south pole.
