Homework: Tides Tide = the rising and falling of ocean waters as a result of the Moon’s gravity and Earth’s gravity The Moon is held in orbit around the Earth by gravity, Moon’s gravity is pulling on Earth, Earth’s gravity is pulling on the Moon The tides are caused by a difference in gravitational pull from the Moon on opposite sides of the Earth.
Homework: Auroras Result from solar wind hitting the Earth. Can disrupt telecommunications and overload electrical power networks. When the high-energy charged particles are carried past Earth’s magnetic field they generate electric currents that flow toward Earth’s poles. Electric currents charge gases in the atmosphere and produce light.
Planetary MotionThe Sun’s gravitational pull keeps objects in the solar system in orbit.
Planetary Motion Johannes Kepler demonstrated that planets orbit in ellipses.
Planetary MotionOrbit = the path of one object revolving around anotherRevolution = the time it takes for an object to orbit another objecti.e. Earth’s revolution is 365.24 days
Planetary MotionRotation = the turning of an object around an imaginary axis running through iti.e. Earth’s rotation is approximately 24 hours
Planetary Motion Retrograde motion is the movement of a planet from east to west in the sky, rather than its normal motion from west to eastImage:ShowsRetrogrademotion ofMars