Rotation, Tilt, Orbits and Seasons Moon and Tides Space Part 1
Space…the final frontier!
If the sun was a golf ball… Earth would be the ball in a ball point pen and 10 ft from the sun 2 more feet would take you to Mars Neptune would be in Lakefield Alpha Centauri is in Winnipeg It takes 8.3 min for the sun’s light to reach us It takes 4.3 years for the light from Alpha Centauri to reach us!! How big?
March 16, 1926 First rockets 13m in 3 sec Within a decade 1500m at 800 km/hr Robert Goddard
Wernher Van Braun
Laika aboard Sputnik 2
1. Geocentric Model Geo = earth, Centr= centre Ptolemy during 2 nd century AD (C.E) Lasted 1500 years Earth is the center of the solar system (instead of the sun) Models of the Solar System
2. Heliocentric model Helio = sun, centr= centre Nicolaus Copernicus (early 1500’s) Orbits with perfect circles 3. Johannes Kepler ( ) demonstrated elliptical orbits Current model = heliocentric with elliptical orbits
Orbit: the closed path a satellite takes around another body -All planets in our solar system orbit the sun -Moons orbit planets -DEMO (ball and string) Orbits Gravity: the force which pulls one mass toward another -Examples: -Human down toward the earth -Earth toward the sun -Moon toward the earth -Causes orbits, prevents satellites from flying off in a straight line
Radius of Earth: 6378 km (1 earth) Radius of Moon: 1738 km (0.273 Earths) Radius of Sun: km (109 Earths) Earth and Moon Orbits x x 10 8
Axis of rotation: The invisible line around which a celestial body rotates Orbit: the closed path a satellite takes around another body Tilt: The angle at which the axis lies relative to the perpendicular of its orbital plane (cardboard cutout in the demo) Rotation and Tilt
Earth: 1 day/rotation Sun: 25 days/rot Moon: 27.3 days/rot Rotation: what effect does it have?
Earth: 23.5° Moon: ° Tilt: what effect does it have? Orbital/
Sun Earth Axis orbital plane Perpendicular
orbital plane
Hemi = half Sphere = 3D circle Hemisphere = half-sphere Demo with half of a broken sun ball Hemisphere
It is day on the side of the earth which faces the sun It is night on the side which faces away from the sun.
What happens when the globe is tilted toward the sun? Away? Direct radiation: what happens when there is more? Globe and Light Demo (dots)
Longer days when our hemisphere is tilted towards the sun (summer). More direct radiation. Shorter days when our hemisphere is tilted away from the sun (winter). Less direct radiation Length of Day and Seasons
Seasons Key Terms: Solstice, Equinox
Seasons Video MJmndBs_EQ1RWYl9hbkNiZlE&usp=sharing
Reading: pg Textbook Questions: pg. 328 # 2-11 Homework
phase2.gif Planetary Like earth, one side of the moon experiences “day”, and the other “night” The phase of the moon is its appearance at different locations in its orbit. 1 full cycle of phases per month (29.5 day orbit) Phases of the moon
Key phases Waxing moon: The bright portion is getting “larger” and sits on the right side Waning moon: The dark portion is getting “larger” and sits on the right side New moon: The moon is not visible (dark side faces earth) Full moon: The entire moon is bright and circular (light side faces earth)
Phases of the Moon
Solar Eclipse: When our view of the sun is blocked out by the moon. Can only occur at a new moon, when the moon is between the Earth and Sun. Lunar Eclipse: When the moon is in the Earth’s shadow. Can only occur at a full moon, when the Earth lies between the moon and Sun. Hand Demo **Solar eclipses can only be seen from some locations on the earth. **Lunar eclipses are visible from anywhere with a view of the moon. Eclipses
Solar Eclipse eclipses
The gravity of the moon pulls the ocean water toward the Moon as it orbits causing tides to rise on that side. Spring tides: The largest tides. They occur when the Moon and Sun are in line with each other (on the same or opposite sides of the earth) so their gravitational forces combine (add up) Neap tides: The smallest tides. They occur when the Moon and Sun are on perpendicular sides of the Earth Tides
Spring and Neap Tides
Hamilton, Calvin J.; Hamilton, Rosanna L., The Moon,Views of the Solar System, 1995–2011Views of the Solar System Wikipedia: Sources