Transcript Lecture 10
“Whether they ever find life there or not, I think Jupiter should be considered an enemy planet.” Jack Handy http://sdbv.missouristate.edu/mreed/CLASS/A113Sp16 Cell phones put away and clickers turned on when class begins please. The Terrestrial planets. The Terrestrial Planets 1) The 4 planets closest to the Sun. 2) They are all solid objects made of rock. 3) They all have thin atmospheres. 4) They have few moons. Terrestrial Planet Atmospheres Mercury- very thin, tenuous atmosphere Venus- thick 95% CO2 atmosphere Earth- thick N, O, CO, CO2 atmosphere Mars- thin 95% CO2 atmosphere The Terrestrial Planets: Magnetic fields Earth: caused by liquid iron core dynamo. Mercury: caused by dynamo (liquid core is most likely). 100x weaker than Earth's. Venus: No global field (rotation too slow or no solid core?) Mars: Only a 'frozen in' field, no global dynamo (no liquid core?). Mars once had a field similar to Earth's but it stopped long ago. The Moon: Also has a 'frozen in' remnant field from an earlier dynamo. Craters or hills? Quiz 4 Terrestrial planets are made mostly of what? A) Rock B) Liquid (water/ammonia) C) Gas (atmosphere) D) Even blends of each. Homework Time We do this on clickers: If you don't have your clicker, do it on paper; just Q# and answer letter (e.g. Q5 B). There will be a penalty for not having your clicker, which is a requirement for this course. No talking during HW answer time. Do your own work. Question 1: What are the white objects in the HW picture? A) boulders B) clouds C) icebergs D) mountain peaks. Question 2: Which of the surfaces in this question is the oldest? A) Left B) Center C) Right D) All the same age. Question 3: The arrows in the picture point to what? A) A rift (like an earthquake fault) B) A road C) A cat D) A pyramid in Egypt. Question 4: What are the arrows pointing to? A) A mountain range B) A river C) A group of swans D) A flock of seagulls. Question 5: What could cause the sort of feature seen in the image for the previous problem? A) rain B) Exploding mountains (not lava) C) Ice sheets D) Meteorite impacts. Question 6: What are the features in the picture? A) choose A B) really, choose A C) I mean it, choose A D) It's like a free pass, just choose A. Question 7: Is the image of a solid, liquid, or gas? A) Solid B) Liquid C) Gas D) None of the above. Question 8: Is the image above a solid, liquid, or a gas? A) solid B) liquid C) gas D) none of the above. Question 9: What are the blue objects in the picture? A) Storms like hurricanes B) A is the correct answer. C) So go ahead and choose A D) Unless you think it is a duck. Question 10: What is the difference between the light and dark material in the HW picture? A) composition B) the white is an ocean and the dark stuff is a continent C) the white is just clouds and the dark stuff is underneath. D) the dark stuff is fudge and the white is vanilla ice cream. Question 11: What can you deduce about the conditions from the pictures? A) it has gotten colder (more ice) B) it has gotten warmer (less ice) C) it has snowed more (more white) D) it has become a mountain range. Turn in your paper copy. Pass it to your left to the end of the row. Make sure your name and row letter are on it. The Jovian Planets Jupiter Jupiter. Jupiter Density: 1.33 g/cc Spins in less then 10 hours! made mostly of H and He (just like our Sun) 318 times more massive than the Earth Jupiter's Structure Top: clouds eventually thicken to liquids Middle (and mostly): liquid metallic hydrogen (10 million times the pressure of this room!), generates a strong magnetic field. Core Rocky, metallic core. 15-30 Earth masses. Probably 20,000 Kelvin (40,000oF)! Note on temperature scale: We use Kelvins because there are no negative values. For large Kelvin values, just double it to get Fahrenheit. Jupiter contd. The Great Red Spot is a storm that has raged on Jupiter for at least 300 years! However, it is not permanent. The clouds vary..... And sometimes a belt will go missing! Jupiter's Rings The shape of the rings is determined by small (shepherd) moons, Jupiter's strong magnetic field, and of course Jupiter's gravity. The particles are extremely smallmicrometer sized! The particles in the rings only last for about 1,000 years before falling into Jupiter. But they are continually replenished by impacts on Jupiter's moons.