4A1 The Sun-Earth-Moon System

Question 1

What is Earth’s rotation?

Answer 1

The spinning of Earth on its axis.

One full rotation takes approximately 24 hours and is responsible for the cycle of day and night.

Question 2

How long does one complete rotation of Earth take?

Answer 2

Approximately 24 hours.

This is known as a solar day, which is about 23 hours, 56 minutes. The slight variation is due to Earth’s orbit, as it needs a bit more time to adjust for the movement in its orbit around the Sun.

Question 3

What is Earth’s revolution?

Answer 3

The movement of Earth around the Sun.

Earth completes one revolution in about 365.25 days, which defines a year.

Question 4

True or False:

Earth’s axis is perfectly perpendicular to its orbital plane.

Answer 4

False

Earth’s axis is tilted at approximately 23.5 degrees relative to its orbital plane.

Question 5

What is the primary consequence of Earth’s axial tilt?

Answer 5

The changing of seasons.

The axial tilt causes variations in the angle and intensity of sunlight received at different latitudes throughout the year.

Question 6

Define:

Solstices

Answer 6

The times when the Sun is at its highest or lowest point in the sky at noon.

Solstices occur twice a year, marking the longest and shortest days: the summer and winter solstices.

Question 7

Fill in the blank:

The equinox occurs when day and night are nearly ______.

Answer 7

equal

During an equinox, the Sun is directly above the equator, leading to nearly 12 hours of daylight and darkness worldwide.

Question 8

When do the equinoxes typically occur?

Answer 8

Around March 21st and September 23rd.

These are known as the vernal (spring) and autumnal (fall) equinoxes, respectively.

Question 9

What causes Earth to experience day and night?

Answer 9

Earth’s rotation on its axis.

As Earth rotates, different parts of its surface move into and out of sunlight, creating day and night cycles.

Question 10

True or False:

The Earth’s revolution affects the length of a day.

Answer 10

False

The Earth’s revolution primarily determines the length of a year, while rotation determines the length of a day.

Question 11

What is the term for the path Earth follows during its revolution?

Answer 11

Orbit

Earth’s orbit is elliptical, meaning it is not a perfect circle but slightly oval-shaped.

Question 12

Fill in the blank:

The tilt of Earth’s axis is approximately ______ degrees.

Answer 12

23.5

This tilt is responsible for seasonal variations in sunlight and temperature.

Question 13

What is the main reason for the seasons on Earth?

Answer 13

The tilt of Earth’s axis combined with its revolution around the Sun.

Seasonal changes result from the varying angles of sunlight caused by axial tilt.

Question 14

True or False:

The Earth’s speed of rotation is constant at all latitudes.

Answer 14

False

The speed of rotation is fastest at the equator and decreases toward the poles due to Earth’s spherical shape.

Question 15

What is the significance of the Tropic of Cancer and the Tropic of Capricorn?

Answer 15

They mark latitudes where the Sun is directly overhead during solstices.

The Sun is overhead at the Tropic of Cancer during the summer solstice and at the Tropic of Capricorn during the winter solstice.

Question 16

Fill in the blank:

Earth’s elliptical orbit causes the Sun’s apparent size to ______ throughout the year.

Answer 16

vary

The Sun appears slightly larger during perihelion and smaller during aphelion due to the varying distance.

Question 17

What are periods of continuous darkness at the poles during winter?

Answer 17

Polar nights

Polar nights occur because the tilted axis prevents sunlight from reaching certain latitudes during winter months.

Question 18

What are midnight suns?

Answer 18

Periods of continuous daylight at the poles during summer.

Midnight suns occur because the tilt of Earth’s axis allows continuous sunlight at high latitudes during summer months.

Question 19

What is the significance of the Arctic and Antarctic Circles?

Answer 19

They define the boundaries of polar day and night.

Areas within these circles experience at least one day of continuous daylight or darkness annually.

Question 20

True or False:

Earth’s axial tilt remains constant over time.

Answer 20

False

Earth’s axial tilt changes very slowly over thousands of years due to gravitational interactions, a phenomenon called axial precession.

Question 21

What is the slow wobble of Earth’s axis over time?

Answer 21

Axial precession

Axial precession alters Earth’s orientation relative to the Sun and affects long-term climate patterns.

Question 22

How does Earth’s revolution change the apparent position of stars?

Answer 22

It causes stars to shift positions throughout the year.

As Earth orbits the Sun, different parts of the sky become visible at different times of the year. This shift in the apparent position of stars is due to Earth’s changing vantage point in its orbit.

Question 23

Fill in the blank:

The angle of sunlight is _________ during summer, leading to warmer temperatures.

Answer 23

higher

A higher Sun angle means more concentrated sunlight and increased heating of the Earth’s surface.

Question 24

Why is the equator consistently warm year-round?

Answer 24

It receives nearly direct sunlight year round.

The equator experiences minimal variation in sunlight angles due to its location.

Question 25

# True or False: The Earth's orbit is a perfect **circle**.

Answer 25

False ## Footnote Earth's orbit is **elliptical**, causing varying distances from the Sun during the year.

Question 26

What happens during the **summer solstice** in the Northern Hemisphere?

Answer 26

It experiences the **longest day** of the year. ## Footnote The North Pole is tilted toward the Sun, leading to maximum daylight hours.

Question 27

# True or False: Earth's tilt creates **uneven** energy distribution across latitudes.

Answer 27

True ## Footnote The axial tilt causes varying sunlight angles, leading to different climate zones.

Question 28

# Fill in the blank: Earth's motions **drive** \_\_\_\_\_\_\_\_\_\_, condensation, and precipitation.

Answer 28

evaporation ## Footnote Earth's rotation and revolution affect solar heating, which drives *evaporation*. Condensation and precipitation, however, depend on additional atmospheric conditions, such as temperature, humidity, and air pressure.

Question 29

What causes **tides** on Earth?

Answer 29

The **gravitational pull** of the Moon and Sun. ## Footnote The Moon’s *gravity* has the most significant effect on tides, but the Sun's gravity also plays a role, though to a lesser extent.

Question 30

What is a **tidal cycle**?

Answer 30

The rise and fall of **sea levels** caused by the Moon and Sun's gravity. ## Footnote A full tidal cycle consists of two high tides and two low tides over approximately 24 hours and 50 minutes.

Question 31

# True or False: Tides occur only **once** per day.

Answer 31

False ## Footnote Most coastal areas experience **two** high tides and two low tides daily, known as a semidiurnal tide cycle.

Question 32

What is a **spring tide**?

Answer 32

A tide that occurs when the **Sun, Earth, and Moon are aligned**. ## Footnote Spring tides produce higher high tides and lower low tides and occur during the new moon and full moon phases.

Question 33

What is a **neap tide**?

Answer 33

A tide that occurs when the **Sun and Moon are at right angles**. ## Footnote Neap tides produce lower high tides and higher low tides and occur during the first and third quarter moon phases.

Question 34

When do spring tides **occur**?

Answer 34

During the **new moon** and **full moon** phases. ## Footnote During these phases, the Sun and Moon are aligned, enhancing their *gravitational effect* on Earth’s oceans.

Question 35

# True or False: Neap tides have **higher** high tides compared to spring tides.

Answer 35

False ## Footnote Neap tides have **lower** high tides compared to spring tides due to the weaker combined gravitational pull of the Sun and Moon.

Question 36

What is the **tidal range**?

Answer 36

The **difference in height** between high tide and low tide. ## Footnote The tidal range varies depending on the Moon's and Sun's relative positions to Earth.

Question 37

# Fill in the Blank: A **larger** tidal range is associated with \_\_\_\_\_\_\_ tides.

Answer 37

Spring ## Footnote *Spring tides* have a larger difference between high and low tides due to the combined gravitational effects of the aligned Sun, Earth, and Moon.

Question 38

What is the primary cause of **eclipses**?

Answer 38

The **alignment** of the Earth, Moon, and Sun. ## Footnote *Eclipses* occur when one of these bodies casts a shadow on another, caused by their relative positions.

Question 39

What happens during a **lunar eclipse**?

Answer 39

The Earth **blocks** the Sun's light, casting a **shadow on the Moon**. ## Footnote *Lunar eclipses* are visible only at night in regions where the Moon is above the horizon during the alignment of Earth’s shadow.

Question 40

When do **solar eclipses** occur?

Answer 40

During a new moon. ## Footnote A solar eclipse happens when the Moon is positioned directly between Earth and the Sun, blocking the Sun's light.

Question 41

# True or False: A solar eclipse **cannot** be seen from any location on Earth.

Answer 41

False ## Footnote A solar eclipse is **visible** only from specific areas on Earth where the Moon’s shadow falls, but it can always be seen from some location within the path of totality or partial shadow during the eclipse.

Question 42

During which moon **phases** do lunar eclipses occur?

Answer 42

Full moon ## Footnote Lunar eclipses occur when Earth’s shadow falls on the Moon, which only happens when the Moon is full.

Question 43

# True or False: Lunar eclipses are visible **only** during the night.

Answer 43

True ## Footnote *Lunar eclipses* occur when the Moon is on the opposite side of Earth from the Sun, making them visible at night.

Question 44

What is the **period** of approximately 18 years after which eclipses repeat?

Answer 44

Saros cycle ## Footnote The *Saros cycle* describes the pattern in which similar eclipses occur, as the Sun, Moon, and Earth return to the same relative positions.

Question 45

What **effect** does a total lunar eclipse have on the Moon's appearance?

Answer 45

The Moon appears **reddish**. ## Footnote During a lunar eclipse, Earth's atmosphere scatters *shorter* wavelengths of light, allowing red wavelengths to reach the Moon.

Question 46

# Fill in the Blank: A total solar eclipse occurs when the Moon completely **blocks** the \_\_\_\_\_\_.

Answer 46

sun ## Footnote In a total solar eclipse, the Moon is perfectly aligned to cover the Sun completely, casting a shadow on Earth.

Question 47

What is the result of a **partial solar eclipse**?

Answer 47

Only **part** of the Sun is covered by the Moon. ## Footnote During a partial solar eclipse, the Sun’s light is only blocked in certain areas, creating a crescent shape.

Question 48

What **phase** of the Moon is required for a solar eclipse?

Answer 48

New Moon ## Footnote Solar eclipses occur during the *new moon* phase, when the Moon is directly between Earth and the Sun.

Question 49

What causes the **phases of the Moon**?

Answer 49

Its **position** relative to the Earth and Sun. ## Footnote As the Moon orbits Earth, different portions of its illuminated side become visible from Earth, creating the phases.

Question 50

Which phase occurs when the **Moon is between Earth and the Sun**?

Answer 50

New Moon ## Footnote During the *new moon*, the side of the Moon illuminated by the Sun is facing away from Earth, making it invisible.

Question 51

What is the phase that immediately **follow the new moon**?

Answer 51

Waxing Crescent ## Footnote In this phase, a small sliver of the Moon becomes visible as it begins to move away from the Sun in the sky.

Question 52

# True or False: The **full moon** occurs when the Moon is on the opposite side of Earth from the Sun.

Answer 52

True ## Footnote During the full moon, the entire illuminated half of the Moon is visible from Earth.

Question 53

# Fill in the Blank: The phase that occurs **after** the full moon is called the \_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_.

Answer 53

Waning Gibbous ## Footnote After the full moon, the Moon starts to wane, with the visible illuminated portion decreasing.

Question 54

What is the Moon phase when it is **three-quarters** through its cycle?

Answer 54

Third Quarter ## Footnote During the third quarter, half of the Moon’s visible surface is illuminated, and it is moving toward the new moon phase.

Question 55

What phase occurs **after** the waxing gibbous?

Answer 55

Full Moon ## Footnote As the Moon’s illumination continues to grow, it reaches the full moon phase, where the entire face is visible.

Question 56

# True or False: A waxing crescent moon **occurs** after a waning gibbous.

Answer 56

False ## Footnote The waxing crescent **follows** the new moon, while the waning gibbous follows the full moon.

Question 57

How long does it take for the Moon to **complete** one full cycle of phases?

Answer 57

Approximately 29.5 days. ## Footnote This is known as a *lunar month*, or synodic month, and marks the period it takes for the Moon to return to the same phase.

Question 58

# Fill in the Blank: The phase in which the Moon is **fully** illuminated is called the \_\_\_\_\_\_ \_\_\_\_\_\_\_.

Answer 58

Full Moon ## Footnote The full moon occurs when the Earth is between the Sun and the Moon, and the entire illuminated side of the Moon is visible from Earth.

Question 59

What is a full moon that appears **larger** due to its proximity to Earth?

Answer 59

Supermoon ## Footnote A **supermoon** occurs when the Moon is at its closest point to Earth in its orbit, called the perigee.

Question 60

What happens **during** the First Quarter Moon?

Answer 60

**Half** of the Moon’s visible surface is illuminated. ## Footnote The first quarter occurs when the Moon has completed about one-quarter of its orbit around Earth.

Question 61

What is **solar wind**?

Answer 61

A stream of **charged** particles from the Sun. ## Footnote Solar wind can affect Earth’s magnetosphere and cause various phenomena like auroras and geomagnetic storms.

Question 62

What **effect** can solar wind have on communication satellites?

Answer 62

It can **interfere** with their signals and operation. ## Footnote Solar wind can disrupt satellite communications by disturbing the electrical systems and signals.

Question 63

# Fill in the blank: The **interaction** between solar wind and Earth’s magnetic field creates \_\_\_\_\_\_\_\_.

Answer 63

auroras ## Footnote Solar wind particles interact with Earth's magnetosphere, exciting atoms in the atmosphere, which results in the display of **auroras**.

Question 64

# True or False: Solar wind can **cause** power outages.

Answer 64

True ## Footnote Solar wind can induce geomagnetic storms that affect power grids and electronics, leading to **blackouts**.

Question 65

What is the primary **cause** of auroras?

Answer 65

Solar wind **interacting** with Earth’s magnetic field. ## Footnote The charged particles in solar wind collide with gases in Earth's atmosphere, causing them to light up and create auroras.

Question 66

# Define: Geomagnetic storm

Answer 66

A **disturbance in Earth's magnetic field** caused by solar wind. ## Footnote Geomagnetic storms can interfere with navigation systems, communications, and power systems.

Question 67

What is the **region** around Earth affected by solar wind?

Answer 67

The magnetosphere. ## Footnote The **magnetosphere** is the area where Earth's magnetic field interacts with solar wind, protecting the planet from the full force of solar radiation.

Question 68

What is a **solar flare**?

Answer 68

A sudden, intense **burst** of energy from the Sun’s surface. ## Footnote Solar flares can release large amounts of radiation and energy, impacting satellites, communications, and power systems.

Question 69

# True or False: The solar wind can **only** cause damage during solar flares.

Answer 69

False ## Footnote Solar wind itself can cause disturbances, but solar flares can **enhance** these effects, leading to more intense phenomena.

Question 70

How does solar wind **affect** GPS systems?

Answer 70

It can cause **errors** in signal reception and navigation. ## Footnote Solar wind can *interfere* with GPS satellites, leading to incorrect positioning data due to disruptions in satellite signals.