Suppose 1.) the date is june 21 and the sun never sets, as it just touches your northern horizon at midnight. You are standing d.) the artic circle. 2.) What do asteroids and comets have in common? A.) most have been unchanged since formation. 3.) You are travelilin in ophen seas and you have located the north celestial pole in the sky. How can you determint ur latitude on earth? A.) the altitude of the NCP is the same as your latitude. 4.) How does a space shuttle take off from a vertical postion? D.) hot gas shoots from rocket engines, shuttle moves in opposite. 5.) How can differentiation occur in a planet? E.)the planet must have a molten interior. 6.) Why isn't earth's atmosphere mostly hydrogen? B.)light gases such as H move faster than heavier gases and escape the earths gravational field 7.) The four Galilian moons are a) a mix of rock and ice, with the ice fraction increasing with distance from Jupiter. 8.) What is not evidence for continental drift d.) lack of impact craters 9.) From where did O2 in the earth's atmosphere originate? Photosynthesis from single celled organisms 10.) The spectrum of the sun appears...d.) light from a dense, hot part of the star passes through a region of cooler gas. H-R Diagram: Main Sequence-stars undergoing H-burning Supergiants: luminous very stars Giants: luminous cooler stars White dwarfs: hot fainter stars Gravatational Equilibrium: initial collapse under gravity heats core; hotter core produces thermal energy; core hot enough to fuse H; energy generated in core "pushes back" against gravity. Star balances at point where pull equals push out. Eventually fuel gone, gravity wins. Birth: molecular clouds; opaque to visible, IR, from cloud to protostar; come together, angular momentum conserved, turns into disk, eventually gets to main sequence, bigger mass get to main sequence in less time, Red giants; core contracts, star expands. Hburning in outer shell, more He, eventually gets gets s hot enough, He ignites, red super g giants
Star-Gas-Star cycle: star forming nebula-main sequence star-red supergiant-explosive outburst (supernova)-black hole, neutron star, recycled chemicals goto interstellar medium, then starts over. Types of Galaxies; Spiral Galaxies- rotating disks with bulge, spiral arms with young blue stars. (gas, star formation in arms) Elipitical galaxies-spheroids of mostly old stars, very little gas or young stars, irregular galaxies Flux, apparent brightness Hubble's Law: galaxies may not following expansion of univers, galaxies have random motions, due to proximity