ASTR 1345 1st Edition Lecture 10 Outline of Last Lecture I. CosmologyA. Geocentric CosmologyB. Heliocentric CosmologyII. OrbitsA.Definition of a PeriodB.Definition of FrequencyC. Definition of PerihelionD.Definition of AphelionIII. Kepler’s LawsA. Kepler’s First lawB. Kepler’s Second LawC. Kepler’s Third LawIV. Definition of Conic SectionOutline of Current Lecture I. GalileoII. Planetary MotionA. Direct MotionB. Retrograde MotionC. Parallax III. ConfigurationsA. ElongationB. OppositionIV. ConjunctionsA. Inferior ConjunctionB. Superior ConjunctionV. Centripetal AccelerationVI. EnergyA. Conservation of EnergyB. Angular MomentumC. Kinetic EnergyD. Potential Energy/Radiative EnergyVII. MatterCurrent LectureThese 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.l.Galileo was one of the first people to look through a telescope and record his observations and he proved that the Earth was not the center of the Universe. Galileo is famous for his contributions to the physics of falling bodies. He made the 1st known telescopic observations of the night sky and he publicized the work of Copernicus. He observed mountains on the Moon, dark spots on the Sun (sunspots), 4 moons orbiting Jupiter, the phases of Venus, the ring on Saturn, and what the Milky Way is made of.ll.Planets rise with the stars in the eastern half of the sky and set with them in the western half.A. Direct Motion is gradual, eastward apparent motion of a planet against the background stars as seen from Earth.B. Retrograde Motion is the occasional backward (westward) apparent motion of a planet against background stars as seen from Earth. This is an optical illusion.C. A Parallax is the apparent displacement of an object relative to more distant objects caused by viewing it from different locations.lll.Configurations are a particular geometric arrangement of Earth, a planet, and the Sun.A. Elongation is the angle between a planet and the Sun as seen from Earth.B. Opposition is the configuration of a planet when it’s at an elongation of 180 degrees and appears opposite the Sun in the sky.lV.Conjunctions is the alignment of two bodies in the solar system so they appear in the same part of the sky as seen from Earth.A. Inferior Conjunction is the configuration when Mercury or Venus is directly between the Sun and the Earth.B. Superior Conjunction is the configuration when Mercury or Venus is on the opposite side of the Sun from the Earth.V.Centripital Acceleration is when an object is moving at a constant speed in a circle. Ac=v^2/r. Without gravity things would move in a straight line. Gravity continuously forces it from its straight line, causing it to move in a circle. The gravitational force on an object always points towards the Earth’s center.Vl.A. The conservation of energy-the form of energy may change the total quantity of energy remains constant.B. Angular Momentum is the measure of how much energy is stored in an object due toits rotation and revolution. It depends on 3 things—how fast an object rotates or revolves, how much mass it has, and how spread out that mass is.C. Kinetic Energy is the energy of motion. KE of a moving object is ½ mv^2. The thermalenergy of a gas is the total KE of its molecules. The temperature of a gas (in K) is proportional to the average KE of its molecules. Heat is the energy transferred from one object to another because of a difference in temperatures.D. Potential Energy can be converted to kinetic energy. Potential energy has many forms, such as gravitational, elastic, electrical, and chemical. Energy units are J (joules) and eV (electron-volts). Radiative energy is carried by EM waves.Vll.Matter is simply material, characterized by its mass. Einstein’s famous equation, E = mc2, indicates that matter is just a form of