Questions and Answers
What causes seasons to change?
The tilt of Earth's axis causes seasons to change.
The first day of fall in the Northern Hemisphere is indicated by the _________.
September Equinox
The Earth takes 365.25 days to do what?
Revolve around the Sun
Where is Earth's northern axis pointing on the first day of winter?
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Why is Earth colder at the poles than at the equator?
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What causes days and nights on Earth?
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What is an equator?
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What is an equinox?
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What is an orbit?
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What is revolution?
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What is rotation?
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What is a rotation axis?
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What is a solstice?
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What are maria?
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What is a phase?
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What is a waning phase?
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What is a waxing phase?
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What is a lunar eclipse?
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What is penumbra?
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What is a solar eclipse?
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What is a tide?
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What is umbra?
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Sun's energy reaches Earth as _______ and _______.
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How long does it take Earth to make one revolution around the Sun?
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What force keeps the Earth revolving around the Sun?
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Rotation is a _______ motion.
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One complete Earth rotation is called a _______ and takes _______ hours.
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Earth's rotation axis is always _______ in the same direction by the same amount.
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Earth's rotation makes objects in the sky appear to move from _______ to _______.
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The energy in a beam of sunlight is spread out more at the _______ than at the _______.
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Earth rotates in a (clockwise/______) direction.
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If the gravity between Earth and the Sun somehow stopped, what would happen to Earth?
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Around what does the Earth revolve?
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Where does the north end of Earth's rotation axis lean during the December Solstice?
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Which season does the December Solstice mark in the Northern Hemisphere?
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Which season does the December Solstice mark in the Southern Hemisphere?
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Why are the temperatures cooler in the Northern Hemisphere during the time near the December Solstice?
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What is true about the number of daylight hours during the March Equinox?
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Which season does the March Equinox mark in the Northern Hemisphere?
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Study Notes
Seasons and Earth's Movements
- Seasons change due to the tilt of Earth's axis relative to its orbit around the Sun.
- The September Equinox marks the first day of fall in the Northern Hemisphere.
- Earth completes one revolution around the Sun in 365.25 days, which defines a year.
Earth's Rotation
- On the first day of winter, Earth's northern axis points away from the Sun.
- Days and nights are caused by Earth's rotation, which takes approximately 24 hours to complete one full turn.
- The equator is the imaginary line dividing Earth into northern and southern hemispheres.
Equinoxes and Solstices
- An equinox occurs when Earth's axis is not tilted toward or away from the Sun, resulting in nearly equal day and night.
- A solstice is the day when Earth's rotation axis is at its maximum tilt toward or away from the Sun, indicating the start of summer or winter.
Moon Features and Phases
- Maria are large, dark, flat areas on the Moon's surface.
- The phases of the Moon refer to the illuminated portion visible from Earth, with waxing phases indicating increasing visibility and waning phases indicating decreasing visibility.
Eclipses
- A lunar eclipse happens when the Moon enters Earth's shadow, while a solar eclipse occurs when the Moon casts its shadow on Earth.
- The penumbra is the lighter, outer part of a shadow where partial light is blocked; the umbra is the central, darker part where light is completely blocked.
Tides and Energy
- Tides are caused by the daily rise and fall of sea level influenced by the gravitational pull of the Moon and Sun.
- Sun's energy reaches Earth primarily in the form of light and thermal energy, more concentrated at the equator than at the poles.
Earth's Stability and Directionality
- The Sun's gravity is the force that keeps Earth in orbit around it; if this force ceased, Earth would move in a straight line away from the Sun.
- Earth rotates counterclockwise, so celestial objects appear to move from east to west in the sky.
Seasonal Variations and Daylight
- During the December Solstice, the northern axis leans away from the Sun, marking winter in the Northern Hemisphere and summer in the Southern Hemisphere.
- Near the December Solstice, temperatures are cooler in the Northern Hemisphere due to reduced sunlight.
- The March Equinox results in nearly equal hours of daylight and darkness worldwide; it marks the start of spring in the Northern Hemisphere and autumn in the Southern Hemisphere.
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Description
Test your knowledge about the dynamics of the Sun-Earth-Moon system with these flashcards. Learn about the causes of seasons, equinoxes, and Earth's revolution around the Sun. Perfect for students looking to grasp key concepts in astronomy.
