Earth, Moon, Sun Relationships Module 8

Day and Night Earth rotates on its axis every 24 hours giving us day and night. When the sun shines on half the earth, we have day. The dark side of earth is in night. Readiness Rotation means to spin on its axis, NOT go around something else. Night Day

Seasons The earth revolves around the sun one time a year. The reason we have seasons is because the earth is tilted on a 23.5 degree angle on its axis. If the earth is tilted towards the sun, the sun shines more directly on the earth, thus we have summer. If the earth is tilted away from the sun, the sun shine less directly on the earth, thus we have winter. When the northern hemisphere experiences one season, the southern hemisphere experiences the opposite season. Readiness Revolves-means for a body to go around another body in space. The tilt of the earth on its axis is what causes the seasons.

Seasons in the Northern Hemisphere Readiness

Lunar Cycle The moon revolves around the earth about once a month or 28 days. This creates what we know as the lunar cycle or moon phases. New moon is always between the sun and the earth. The moon travels in a counter-clockwise (opposite of a clock) motion around the earth. About 7 days after a new moon phase, the moon will wax until it’s a 1st quarter. 7 days later, the moon will have waxed into a full moon. 7 days later, the moon will wane into a last quarter. 7 days later, the moon will wane into a new moon again. Readiness The reason we do not see a new moon is because the side of the moon we are looking at is not reflecting any light from the sun. The sun is actually reflecting off the back side of the moon, that we can’t see from earth’s view point. The reason we see a full moon is because the sun’s light is fully being reflected off the moon’s surface we are looking at from earth’s viewpoint.

Lunar Cycle Readiness

Ocean Tides High tide is caused by the gravitational pull of the moon upon earth’s large bodies of water. Low tide is caused when the pull of the moon’s gravity is not acting directly on the earth. Readiness High tides occur 2x a day, everyday normally. Low tides occur 2x a day everyday normally.

Spring Tides Spring Tides are higher than usual high tides. The sun, earth, and moon are aligned. Spring tides occur during new moon and full moon phases. Readiness Spring tides only occur 2x a month, normally. Because the earth is aligned with the moon and sun, both the sun’s and moon’s gravitational pull are creating a large tidal bulge on large bodies of water on earth.

Neap Tides Neap Tides are lower than usual high tides and higher than usual low tides. The sun, earth, and moon form a right angle. Neap tides occur during 1st Quarter and Last Quarter moon phases. Readiness Neap tides generally occur 2x a month.