ASTR 1345 1st Edition Lecture 6 Outline of Last Lecture I. The Geocentric UniverseII. The SunA.Definition of Celestial EquatorB.North and South Celestial PoleC.Definition of DeclinationD.Definition of Right AscensionE.Prime MeridianF.Diurnal MotionG.Sidereal PeriodH.ZenithI.CircumpolarJ.EclipticK.EquinoxL.Winter and Summer SolsticeM.ZodiacOutline of Current Lecture I. Definition of GravityII. PrecessionIII. Phases of the MoonA. Definition of Lunar PhasesB. New MoonC. Waxing Crescent MoonD. First Quarter MoonE. Quarter MoonF. Waxing Gibbous MoonG. Full MoonH. Waning Gibbous Moon, Third Quarter Moon, and Waning Crescent MoonIV. Sides of the MoonA. Far SideB. Dark SideC. Bright SideD. Definition of TerminatorV. SynodicThese 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.VI. SiderealVII. Tropical YearCurrent Lecturel.Gravity is the universal force of attraction between all matter.ll.Precession is a slow conical motion of Earth’s axis of rotation caused by the gravitational pull of the Moon and the Sun on Earth’s equatorial bulge. The precession of the equinoxes is the slow westward motion of the equinoxes along the ecliptic because of Earth’s precession. lll.A. Lunar phases are the names given to the apparent shapes of the Moon seen from Earth. The Moon completes a full cycle of phases in 29.5 days.B. When the Moon is a tiny crescent it is called the New Moon. Its moonrise is at dawn.C. During the 7 days following the new phase more of the Moon’s illuminated hemisphere becomes exposed to our view, this is called the Waxing Crescent Moon. Its moonrise is late morning and it is visible in the evening.D. The First Quarter Moon is when we see half of the illuminated hemisphere and half of the dark hemisphere. Its moonrise is at noon and is visible before midnight.E. A Quarter Moon is how far in its cycle the Moon has gone, rather than what fraction of the Moon appears lit by sunlight.F. The Waxing Gibbous Moon is during the next week when more of the illuminated hemisphere can be seen from Earth. Its moonrise is in the afternoon and it’s visible until early morning. Gibbous means rounded on both sides.G. A Full Moon is when the Moon arrives on the opposite side of the Earth from the Sun, we see virtually all of the fully illuminated hemisphere. Its moonrise is at dusk and it’s visible all night.H. Over the following two weeks we see less and less of the illuminated hemisphere as the Moon continues along its orbit. The movement produces phases called the Waning Gibbous Moon, Third Quarter Moon, and the Waning Crescent Moon. The Waning Gibbous’ moonrise is in the evening and it’s visible from the evening on. The Third Quarter Moon’ moonrise is at midnight and it’s visible after midnight. The Waning Crescent’ moonrise is at early morning and it’s visible in the early morning.lV.A. The far side of the Moon is the side of the Moon facing away from the Earth.B. The dark side of the Moon is the side of the Moon on which the Sun is not shining.C. The bright side of the Moon is on the right (west) side of the Waxing Moon while the bright side is on the left (east) side of the Waning Moon.D. The terminator is the line dividing day and night on the surface of anything orbiting the Sun; it’s the line of sunrise or sunset.V.A synodic Period is a measured period from a planet or Moon. A synodic month or lunar month is the time it takes the Moon to complete one 29.5 day cycle of phases and it is measured with respect to the Sun rather than the stars.Vl.Sidereal period is measured with respect to distant stars. A sidereal month is the time it takes the Moon to complete one full orbit of 360 degrees around the Earth.Vll.A tropical years is a synodic year measured between successive vernal equinoxes which is shorter than a sidereal year by about 20