ASTR 1345 1st Edition Lecture 23 Outline of Last Lecture I. Jupiter’s MoonsA. IoB. EuropaII. SaturnA. Saturn’s RingsB. TitanIII. UranusIV. NeptuneOutline of Current Lecture I. MeteoroidsA. MeteorsB. Meteor ShowerC. Meteorites1. Stony Meteorites2. Stony-Iron MeteoritesII. AsteroidsIII. Comets and their PropertiesA. ComaB. Hydrogen EnvelopeC. Tails1. Gas Tails2. Dust TailsIV. Kuiper BeltV. Oort CloudCurrent Lecturel.Meteoroids are rocky and metallic space debris found orbiting the Sun. They are fragments fromcomets or asteroids.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.A. Meteors are meteoroids that have been vaporized in the atmosphere of a planet because they are trying to collide with it. Some common types of meteors are fireballs, bolides, and shooting stars.B. Meteor showers are meteors that can be observed, radiate, and originate from one point in the sky. They are produced when a space body such as planets or moons pass through orbit of debris left by a comet. They usually occur in fixed regions in thesky (constellations).C. Meteorites are the surviving fragments of meteoroids that reach Earth’s surface. Some common types of meteorites are the stony and stony-iron meteorites.1. Stony meteorites are created when a meteorites outer layer melts during its descent through the atmosphere.2. Stony-iron meteorites account for 1% of all meteorites that fall on Earth. Theyconsist of equal amounts of rock and iron, and come from boundary regions between iron cores and stony crusts.ll.Asteroids may have been where life originated and the chance of them hitting Earth is every 10,000 years. The one that killed the dinosaurs is once every 100 million years. The asteroid beltsits between Mars and Jupiter and orbits like a donut and Jupiter affects their motion.lll.Comets are dust, ice, rocky, and contain carbon. When they pass within 20 AU from the Sun their ice begins going gaseous. This is called sublimation and is the way fog is formed. They reside in the Oort Cloud and the Kuiper Belt.A. One property of a comet is its coma. The coma creates the comet’s atmosphere and distorts light, giving it a fuzzy appearance. The largest coma measures more than 1 million km. B. The hydrogen envelope is a gas cloud surrounding the nucleus beyond the coma. It is20 million km in diameter and not visible to the human eye.C. Comet’s tails can be gas or dust. The largest solid particles remain closer to the comet while the smaller particles are further.1. A gas tail is a cloud of positively charged ions in the gas phase caused by the magnetic field of the Sun.2. The dust tail is a cloud of tiny particles in solid phase. The curved shape comes from the combo of momentum and solar wind/radiation pressure.lV.The Kuiper Belt is a flat ring of icy small bodies that revolve around the Sun beyond the orbit of Neptune. Their elliptical plane in space is 30 AU to 200 AU from the Sun. It contains trillions of icy objects and believed remnants of the early solar system. Pluto was considered the first true Kuiper Belt Object. There are two types of KBO’s, the classical (circular orbits, closer to the Sun) and the scattered (elliptical orbits, farther from the Sun).V.The Oort Cloud lies past the Kuiper Belt. It’s a spherical cloud of small icy bodies, inferred to revolve around the Sun more than 1,000 times the orbit of Neptune and extends roughly 50,000AU from the