Astronomy Notes Wednesday Moon Know the theory of the origen of the moon Mercury and Venus Mercury is the closest planet to the sun Venus is the Earth s sister planet They are the only other terrestrial planets made mostly of rock Atmospheres prohibit life Mercury the earth 29 degrees Maximum elongation the sun and mercury form the maximum angle from You can do some calculations Mercury is at the 90 degree angle Finding the distance from earth to mercury at maximum elongation Sin theta distance ms distance es The distance from the earth to the sun is twice the distance of mercury to the sun It s rotating slowly It takes a year to get to midnight Given a system construct an angle From noon to noon it takes two mercury years Determine a mercury year by the distance Mercury year is a third of an earth year Noon to noon is 8 months Facing the sun for four months One side is very cold One side is very hot Very little atmosphere greater thermal velocity overcoming escape velocity 10 22 atmospheres many craters Crater within a crater the crater on the inside is younger Scarps propogation of melded material Broken terrain directly opposite a giant crater caused by a large impact seismic waves conservation of momentum The Caloris impact Mercury is denser or as dense as the earth The metallic core is bigger than the mantle Why are heavy elements on mercury as opposed to less on the outer planets the gravity of the sun they sink in The solar system was in a gaseous state in the beginning Less than 0 1 of the universe came from supernova explosions We are a second generation solar system Venus How do we know how the planets rotate we send radar waves and they bounce off of the planet the waves are Doppler shifted Venus rotates the opposite of earth The only planet that does that The rotation is very slow 70 of the earth s year To get from noon to midnight it takes a quarter of a venus year Huge atmosphere which is only carbon dioxide To get from carbon dioxide to oxygen we use plants 700 Celsius retrograde rotation Surface pressure 90 atmospheres CO2 gives you much heavier air Lava flow Pancake domes Same escape velocity as earth It rains sulfuric acid Mars We see craters Theres something at the center of a crater when things collide Volcanoes Mars is smaller than the earth But it has a big mountain Channels from water System of chasms Landslides High sheer cliffs There was water on mars Outflow channels You can see islands Water on the polar caps Global dust storms Masses of sand moves Clouds Most earthlike environment Evidence of ancient oceans 1 88 years orbital period 1 5Aus Two satellites 25 degree axial tilt Iron oxide covers the planet Meteors Meteorites and Asteroids Why do we have a region where there are no planets This is the asteroid belt They all move on an ellipse that can cross the earth s path Millions of them They never formed a planet Most of the inner asteroids were eaten up by the inner planets The probability for them to collide in a bigger space is less
View Full Document
Unlocking...