LESSON PHENOMENON & ESSENTIAL QUESTION • https://www.edumedia-sciences.com/en/media/308sundial • Essential question: • How does Earth moves through space? When Earth turns a complete spin on its axis. It takes one day = 24 hours. Is a complete path around the sun. It takes 365 ¼ days = 1 year. https://www.youtube.com/watch?v=nTxqrUxCjDQ https://www.youtube.com/watch?v=bjal-ozKSL0 https://www.youtube.com/watch?v=cDed5eXmngE Rotation Revolution Around its axis Around the sun Take 24 hours or 1 day Takes 365 days or 1 year Causes day and night Causes the seasons Earth’s orbit • Orbit is the path revolving objects follow. • Earth's orbit is shaped like ellipse, flattened circle. The imaginary line about which Earth rotates. Earth’s axis is tilted. EARTH’S TILTED AXIS • At any point in time, half of Earth’s surface faces the sun and the other half faces away from the sun. (hemisphere) • The tilt of Earth’s axis affects the length of the day. • If the axis were not tilted, day and night would each be twelve hours long. • There are more hours of daylight and fewer hours of darkness during summer. • In winter, the amount of daylight is shorter. • https://www.youtube.com/watch?v=Em3TlqNOUsk EARTH’S TILT AND HEMISPHERES • Earth’s tilt causes the sun to strike different parts of Earth at different angles. • At any point of time, each hemisphere gets more or less sunlight than the other. • Seasons are caused because of both Earth’s tilted axis and revolution around the sun. • https://www.youtube.com/watch?v= e9MU4TouzII • https://www.youtube.com/watch?v= 6SzjlsuyTdk The seasons change as Earth moves around the sun And the tilt of the Earth’s axis. The part with least direct sunlight The part that gets the most direct sunlight Neither the top nor the bottom half is tilted toward or away from the sun THE FOUR SEASONS • When the Northern hemisphere tilts away from the sun, the Northern hemisphere doesn’t receive much energy from the sun and temperatures are lower. • In the Northern hemisphere, this is winter. • The Southern hemisphere is opposite to the Northern hemisphere. • The Southern hemisphere towards the sun, so sun’s energy is more concentrated. The surface receives more energy and the temperature gets warmer. • In spring and autumn, both hemispheres receive equal warmth from the sun making temperature the same in both hemispheres. • https://www.edumediasciences.com/en/media/371-days-and-nightsover-the-year SUMMER SOLSTICE • The summer solstice is when the sun is the highest at the sky. • The northern hemisphere is tilted towards the sun the most during the summer solstice. • During the summer solstice, day time is the longest. • Summer solstice in the Northern hemisphere occurs around June 21st each year. • During the summer solstice in the northern hemisphere, there is winter solstice in the southern hemisphere. • https://www.khanacademy.org/science/cosmo logy-and-astronomy/earth-history-topic/earthtitle-topic/pi/season-simulator WINTER SOLSTICE • The winter solstice is when the sun is the lowest at the sky. • The northern hemisphere is tilted away from the sun the most during the winter solstice. • During the winter solstice, day time is the shortest. • Winter solstice in the Northern hemisphere occurs around December 21 st each year. • During the winter solstice in the northern hemisphere, there is summer solstice in the southern hemisphere. https://www.youtube.com/watch?v=guSb2IrLuvg EQUINOX • During an equinox, day and night are each twelve hours long. • In the Northern hemisphere, the spring or vernal equinox occurs around March 21st . • In the Northern hemisphere, the autumn equinox occurs around September 21 st . • When it's spring equinox in the Northern hemisphere, it's autumn equinox in the Southern hemisphere. • https://www.youtube.com/watch?v=aSfc7gx3RLk Links: https://www.youtube.com/watch?v=t6MCtB752AE https://www.youtube.com/watch?v=f4ZHdzl6ZWg https://www.youtube.com/watch?v=wz01pTvuMa0 • Important information about the moon. The moon doesn’t make its own light. It reflects the light of the sun. The moon revolves around Earth. At any time, half of the moon is lit by the sun while the other part is dark. How long does it take the moon to complete revolution around the earth ? MOON PHASES • The moon appearance changes as it revolves around Earth. • The different shapes of the moon in the sky are called moon phases. • As the moon appears to get larger, it’s waxing. • As it appears to get smaller it’s waning. Full moon Gibbous moon Moon is almost full. New moon Moon is not seen at all. Quarter moon Moon is half full. Crescent Moon appears to be silver. Waxing Waning Crescent Crescent Third quarter