Earth-Moon-Sun Relationship Earthshine Project, BBSO (http://www.bbso.njit.edu/espr/fig10.html
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, 23½0 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 23½0N (Tropic of Cancer) or 23½0S (Tropic of Capricorn) latitude, coincides with the 1st day of summer or winter
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. http://www.lon-capa.org/~mmp/applist/seasons/cd190b.htm
The Moon 1. Earth’s only natural satellite 384,000km away, 1/6th the gravity of Earth Noon temp. of 1300C, night temp. of -1750C Surface features Dark, flat plains called marias 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 16th, 1969
Moon Stats No light of its own!!
The Moon rotates in 27.3 days. The Moon orbits Earth in 27.3 days. Because the Moon rotates and revolves at the same rate, we only see one side The Near Side The NEAR side There is NO DARK SIDE There is a FAR side….
Earth and Moon to Scale If Earth were a basketball, then the Moon would be a tennis ball, 23.5 feet away http://visibleearth.nasa.gov/view_rec.php?id=1624
Moon’s Orbit Orbits (revolves around) Earth every 27.3 days Elliptical orbit (not a perfect circle) • 360,000 km 406,000 km • 224,000 miles 252,000 miles http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=442
Moon Phases 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
Misconception Alert!!! New moons are not created by the Earth “getting in the way”
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 Stats Moon’s orbit around Earth is inclined about 5 degrees to Earth’s plane of orbit around the Sun Ecliptic plane Moon’s orbital plane Moon Earth Sun Image created by LPI staff
Earth-Moon Revolutions The earth and moon revolving around the barycenter. Notice how the earth moves slightly.
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’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. http://averyhenderson.files.wordpress.com/2008/12/solarinteraction1.jpeg