EARTH 3rd Rock from the Sun
Kick off space with YouTube “Planet Earth (views from space)”
Earth FYI Earth’s axis is on a 23.5˚ tilt Earth has a rotational period of 24 hours and an orbital period of 365.25 days (4 x 0.25 = leap year) Earth’s surface is roughly 70% water
Day n’ Night Hemisphere facing away from the Sun is in darkness; towards the Sun its daytime Days get longer leading up to the summer solstice (June 21) and shorter after that
Seasons Earth is tilted Earth circles the Sun on an elliptical orbit We are not closer to the Sun in summer – actually the opposite! Parts of Earth receive varying light intensities
Seasons Earth is tilted (still) Parts of Earth receive varying light intensities from Sun When N. Hem. tips toward Sun - summer When N. Hem. tips away from Sun - winter http://www.bbc.co.uk/learningzone/clips/the-earths-orbit-of-the-sun/1592.html
YouTube “what causes the seasons on Earth?”