Earth-Moon-Sun Relationship Earthshine Project, BBSO (

Earth-Moon-Sun Relationship Sphere – a round, three-dimensional object whose surface at all points is the same distance from its center Axis – an imaginary line around which an object spins

Earth-Moon-Sun Relationship Rotation – the spinning of an object around its axis Revolution – the orbiting of one object around another, like Earth revolving around the sun Ellipse – an elongated, closed curve; the shape of planetary orbits

Why do we have Seasons? They are caused by the tilt of Earth ’ s axis, 23½ 0 Equinox – when the noon sun is directly overhead at the equator, equal hours of daylight and darkness Solstice – when the noon sun is directly overhead at either 23½ 0 N (Tropic of Cancer) or 23½ 0 S (Tropic of Capricorn) latitude, coincides with the 1 st day of summer or winter

Great sites…. ns/animations/01_EarthSun_E2.html ns/animations/01_EarthSun_E2.html ns/animations/01_EarthSun_E2.html ns/animations/01_EarthSun_E2.html /seasons.html - seasons /seasons.html - seasons /seasons.html /seasons.html asons/seasonsgraph.html -seasons asons/seasonsgraph.html -seasons asons/seasonsgraph.html asons/seasonsgraph.html w.php - day and night w.php - day and night w.php w.php

Path of the Ecliptic The apparent path of the Sun across the sky. In summer, the Sun's path is longest, and so are the days. In winter, the Sun's path is shortest, and so are the days.

The Moon 1. Earth ’ s only natural satellite ,000km away, 1/6 th the gravity of Earth 3. Noon temp. of C, night temp. of C 4. Surface features 1. Dark, flat plains called marias 2. Bright areas called highlands

The Moon (cont.) The period of rotation equals the period of revolution around the Earth Apollo 11 put Neil Armstrong and Edwin “Buzz” Aldrin on the moon on July 16 th, 1969

The Moon (cont.) Lunar Eclipse – when Earth passes between the moon and the sun

The Moon (cont.) Solar Eclipse – when the moon passes between Earth and the sun

Earth-Moon Revolutions The earth and moon revolving around the barycenter. Notice how the earth moves slightly.

Tides - Caused by moon’s gravitational pull - Spring Tide – the moon, Earth and sun align - Neap Tide – when the moon, Earth and sun form a right angle

Moon Phases Changes in appearance of the moon as it orbits Earth every 29½ days New Moon – when the side facing Earth is totally dark First Quarter Moon – when the right half of the moon facing Earth is lit Full Moon – when the side facing Earth is completely lit Third Quarter Moon – when the left half of the moon facing Earth is lit

Why do we NOT have a Lunar Eclipse every month? Why do we NOT have a Lunar Eclipse every month?

Earth’s magnetic field Basically a ‘magnet’, exerting a magnetic field surrounding the earth, which effectively extends several tens of thousands of kilometers into space, is called the magnetosphere.

Earth’s Magnetic Field Magnetosphere protects us from the Solar Wind.

What is Solar Wind A stream of energized, charged particles, primarily electrons and protons, flowing outward from the Sun A stream of energized, charged particles, primarily electrons and protons, flowing outward from the Sun Travels through the solar system at speeds as high as km/s (and at a temperature of 1 million degrees (Celsius). Travels through the solar system at speeds as high as km/s (and at a temperature of 1 million degrees (Celsius). Made of plasma. Made of plasma.