Rotation and Revolution
What is the difference between rotation and revolution?
One complete rotation takes 24 hours, which creates one day.
True or False: Seasons are caused by Earth being closer to the Sun.
Seasons are caused by Earth's tilted axis, not its distance from the Sun.
About how long is one lunar cycle?
Approximately 29.5 days or around 1 month
Which model places the Sun at the centre?
Heliocentric Model
Which celestial body has the greatest effect on tides?
The Moon, because its gravity has the strongest effect on Earth's oceans.
What movement causes day and night?
Day and night are caused by Earth rotating on its axis. The side facing the Sun experiences day, while the opposite side experiences night.
What season is Australia in during December?
Why do we always see the same side of the Moon?
The Moon rotates once on its axis in the same amount of time it takes to orbit Earth. This is called synchronous rotation, so the same side always faces Earth.
Which model places the Earth at the centre?
Geocentric Model
How many high tides usually occur each day?
Two high tides and two low tides.
How long does Earth take to revolve around the Sun?
Earth takes 365¼ days (about one year) to complete one revolution around the Sun.
What actually causes the seasons?
The seasons are caused by Earth's 23.5° tilt as it revolves around the Sun. The hemisphere tilted towards the Sun receives more direct sunlight and has summer, while the hemisphere tilted away has winter.
Why does the Moon appear to change shape?
The Moon does not change shape. As it orbits Earth, we see different amounts of its sunlit half, creating the lunar phases.
Name one similarity between the two models.
Both models attempt to explain the movement of the Sun, Earth and Moon, and both describe objects moving through space.
What causes a neap tide?
A neap tide happens when the Sun and Moon are at right angles to Earth. Their gravitational pulls partly cancel each other out, producing smaller tidal differences.
How long does one complete rotation of Earth take?
One complete rotation takes 24 hours, which creates one day.
What is an equinox?
An equinox occurs when both hemispheres receive equal amounts of sunlight, so day and night are nearly the same length. It happens in March and September.
What is the name of the phase when the Moon is completely illuminated?
Full Moon
Which model is accepted by modern science?
The heliocentric model, because evidence shows Earth and the other planets orbit the Sun.
During a lunar eclipse, what is between the Sun and Moon?
Earth is positioned between the Sun and the Moon, blocking sunlight from reaching the Moon.
Why is England several hours behind Australia?
Earth rotates from west to east. As Earth spins, different parts of the planet face the Sun at different times, creating different time zones. England is on a different longitude, so it experiences daylight later than Australia.
Why does the Southern Hemisphere have winter while the Northern Hemisphere has summer?
Earth's axis is tilted. When the Southern Hemisphere is tilted away from the Sun, it receives less direct sunlight and has winter. At the same time, the Northern Hemisphere is tilted towards the Sun and experiences summer.
Describe the sequence from New Moon to Full Moon and back.
New Moon → Waxing Crescent → First Quarter → Waxing Gibbous → Full Moon → Waning Gibbous → Third (Last) Quarter → Waning Crescent → New Moon.
Give two differences between the heliocentric and geocentric models.
Heliocentric
Sun is at the centre
Earth orbits the Sun
Accepted scientific model
Sun orbits the Earth
Historical Model
Why are there two high tides and two low tides every day?
The Moon's gravity creates two bulges of ocean water—one on the side closest to the Moon and one on the opposite side. As Earth rotates through these bulges every 24 hours, most places experience two high tides and two low tides.