Show:
Earth's Motion
Seasons
Moon's Formation and Motion
Moon Phases
Eclipses and Tides
100
What keeps Earth from flying outward into space from its present position?
The inward gravitational pull of the Sun
100
What causes the seasons to change?
The tilt of Earth's rotation axis, combined with Earth's motion around the Sun, is what causes the seasons to change.
100
Why are we able to see the Moon in the night sky?
Because the light from the Sun reflects off the moon and into your eyes.
100
What is a phase?
The potion of the Moon or a planet reflecting light as seen from Earth.
100
Explain the difference between the umbra and the penumbra.
Umbra is the central, darker part of a shadow where light is totally blocked, the penumbra is the lighter part of the shadow where light is partially blocked.
200
Earth’s orbit is best described as which shape?
nearly circular
200
What possible seasons could it be, in each hemisphere, when the North end of the rotation axis is tilted toward the Sun?
This is when spring and summer happen in the northern hemisphere, and fall and winter happen in the southern hemisphere.
200
What causes the Moon to revolve around Earth?
The gravitational pull of Earth on the Moon causes the Moon to move in an orbit around the Earth.
200
What is the sequence of the moons phases called? About how long does it take?
It is known as the lunar cycle and it takes 29.5 days or slightly more than four weeks.
200
Why do we not experience solar and lunar eclipses each month?
The Sun, Moon, and Earth must be in exact alignment for an eclipse to occur. This is difficult to accomplish due to the Moon's orbital path being slightly tilted.
300
What does revolution mean? How long is the Earth's revolution?
The motion of one object around another object. Earth's revolution is approximately 365.24 Days.
300
Explain what is happening during the Winter Solstice. What day does it usually occur?
The north end of the rotation axis is away from the Sun, days in the northern hemisphere are shortest and nights are longest, it is winter in the northern hemisphere and summer in the southern hemisphere. Usually occurs on December 21 or 22.
300
Why do we only see one side of the moon?
The moon revolves around Earth in the same amount of time the moon takes to rotate on its axis.
300
What is happening during a waxing phase?
More of the Moon's near side is lit each night.
300
What is the difference between a solar and lunar eclipse? Explain.
A solar eclipse occurs when the Sun, the Moon, and the Earth are in exact alignment causing the Moon to cast the shadow onto the Earth. A lunar eclipse occurs when the Sun, the Earth and the Moon are in exact alignment causing the Earth to cast the shadow onto the Moon.
400
Explain why it is warmer at the Equator and colder at the poles.
The energy in a beam of sunlight tends to become more spread out the farther you travel from the equator. This means that regions near the poles receive less energy than regions near the equator. This makes Earth colder at the poles and warmer at the equator.
400
What degree is the Earth's axis tilted?
23.5 degrees
400
Explain the difference between craters, maria, and highlands.
Craters are depressions that formed when objects crashed into the Moon, maria are the large, dark, flat areas on the Moon, and highlands are light-colored areas on the Moon that are higher than the maria and covered with craters.
400
What is happening during a waning phase?
Less of the Moon's near side is lit each night.
400
Explain how the Moon's gravitational pull is affecting the Earth's high and low tides.
The Moon's gravity is slightly stronger on the side of Earth closer to the Moon and slightly weaker on the side of Earth opposite the Moon. These differences cause tidal bulges in the oceans on opposite sides of Earth. High tides occur at the tidal bulges, and low tides occur between them.
500
What does rotation mean? What direction does the Earth rotate? How long does it take the Earth to rotate?
A object spinning on its axis. The Earth rotates in a counterclockwise direction. It takes the Earth about 24 hours to make one full rotation.
500
What is an equinox? How many do we have a year? When do they occur?
During an equinox the rotation axis is leaning neither towards nor away from the Sun. There are about 12 hours of daylight and 12 hours of darkness everywhere on Earth. We have two, spring, March 21 and autumn, September 21.
500
What is the Giant Impact Hypothesis? Explain.
About 4.6 billion years ago, an object about the size of the planet Mars collided with Earth. The impact ejected vaporized rock that formed a ring around Earth. Eventually, the material in the ring cooled, clumped together, and formed the Moon.
500
What are the four major phases of the Lunar Cycle? And explain each one.
First quarter- Moon's entire western half is lit. Full Moon- Moon's near side is completely lit. Third quarter- Moon's eastern half is lit. New Moon- Moon's near side is completely dark (no visible moon).
500
What is happening during spring tides? Neap tides?
Spring tides occur during full moon and new moon phases. This is when the Sun's and the Moon's gravitational effects combine and produce the higher high tides and the lower low tides. Neap tides occur at the first and third quarter moon phases. The Sun, Earth, and Moon form a right angle, this causes the tides to be about equal all the way around.