Motions of the Solar System. Earth’s Motions Earth has Three Motions 1. Daily 2. Yearly 3. Cyclic.

Motions of the Solar Motions of the Solar SystemSystem

Earth’s MotionsEarth’s Motions

Earth has Three MotionsEarth has Three Motions1.1. DailyDaily2.2. YearlyYearly3.3. Cyclic Cyclic

Earth’s MotionsEarth’s MotionsRotationRotation Causes Day and NightCauses Day and Night Two types of DayTwo types of Day

SiderealSidereal• Time it takes for the Earth to make one Complete rotationTime it takes for the Earth to make one Complete rotation• 23 hrs and 56 minutes23 hrs and 56 minutes

SolarSolar• Time it takes to go from one Noon to the NextTime it takes to go from one Noon to the Next• 24 hours24 hours

Earth has a tilt of 23.5 DegreesEarth has a tilt of 23.5 Degrees One cause of the seasonsOne cause of the seasons

How Fast are We Moving?How Fast are We Moving?

Earth’s MotionsEarth’s MotionsRevolutionRevolution Earth’s Yearly Journey around the SunEarth’s Yearly Journey around the Sun 365 days 365 days One Cause of the SeasonsOne Cause of the Seasons

Changes the Amount of solar radiation reaching Changes the Amount of solar radiation reaching the earththe earth

AphelionAphelion Furthest point away from the sunFurthest point away from the sun

PerihelionPerihelion Closest point to the sunClosest point to the sun

Annual Motion of the EarthAnnual Motion of the Earth

Earth’s Annual Motion around the Sun is Earth’s Annual Motion around the Sun is an ellipsean ellipse

EllipseEllipse An Elongated Closed CircleAn Elongated Closed Circle Sun is not at CenterSun is not at Center

Earth’s MotionsEarth’s Motions

PrecessionPrecession

The Cause of the SeasonsThe Cause of the Seasons

Sun Position Relative to EarthSun Position Relative to Earth

EventEvent Degrees in Degrees in LatitudeLatitude DateDate SeasonSeason

Vernal EquinoxVernal Equinox 0 or Equator0 or Equator March 21March 21stst SpringSpring

Summer SolsticeSummer Solstice 23.523.500 N or N orTropic of CancerTropic of Cancer June 21June 21stst SummerSummer

Autumnal Autumnal EquinoxEquinox 0 or Equator0 or Equator September 21September 21stst FallFall

Winter SolsticeWinter Solstice 23.523.500 S or Tropic S or Tropic of Capricorn of Capricorn December 21December 21stst WinterWinter

No Tilt, No SeasonsNo Tilt, No Seasons

Height of Sun in SkyHeight of Sun in Sky

Angle of InsolationAngle of Insolation

Angle of InsolationAngle of Insolation

Length of Day and LatitudeLength of Day and Latitude

Latitude and Amt. of Solar Latitude and Amt. of Solar RadiationRadiation