Earth, Sun, and Moon

What causes day and night on Earth?

• The Earth's rotation

• The Earth's revolution

• The Moon's rotation

• The Sun's movement

Answer explanation

Day and night on Earth are caused by the Earth's rotation on its axis. As the Earth spins, different parts face the Sun, creating daylight, while the opposite side experiences night.

How long does it take for the Earth to complete one revolution around the Sun?

• 24 hours

• 365.25 days

• 30 days

• 12 months

Answer explanation

The Earth takes approximately 365.25 days to complete one full revolution around the Sun, which is why we have a leap year every four years to account for the extra quarter day.

What phase of the Moon occurs when the entire face of the Moon is illuminated by the Sun?

• New Moon

• Full Moon

• First Quarter

• Last Quarter

Answer explanation

The Full Moon phase occurs when the entire face of the Moon is illuminated by the Sun, making it fully visible from Earth. In contrast, the New Moon phase has no illumination, while First and Last Quarters show only half.

What is the shape of Earth's orbit around the Sun?

• Perfect circle

• Oval (ellipse)

• Triangle

• Square

Answer explanation

Earth's orbit around the Sun is not a perfect circle; it is an oval shape known as an ellipse. This elliptical orbit is a result of gravitational forces and is described by Kepler's laws of planetary motion.

The Earth is closer to the Sun than the Moon.

• True

• False

Answer explanation

The Earth orbits the Sun at an average distance of about 93 million miles, while the Moon orbits the Earth at an average distance of about 238,855 miles. Therefore, the Earth is indeed closer to the Sun than the Moon.

The Moon has its own light source.

• True

• False

Answer explanation

The Moon does not have its own light source; it reflects sunlight. Therefore, the statement is false.

A lunar eclipse happens when the Earth is between the Sun and the Moon.

• True

• False

Answer explanation

A lunar eclipse occurs when the Earth is positioned directly between the Sun and the Moon, blocking sunlight from reaching the Moon. Therefore, the statement is true.

The Earth’s axis is tilted, which causes the seasons.

• True

• False

Answer explanation

The Earth's axis is tilted at an angle of about 23.5 degrees. This tilt causes different parts of the Earth to receive varying amounts of sunlight throughout the year, leading to the changing seasons. Therefore, the statement is true.

Explain what causes the seasons on Earth.

• The Earth's distance from the Sun

• The tilt of the Earth's axis

• The Earth's rotation speed

• The Moon's phases

Answer explanation

The seasons on Earth are caused by the tilt of the Earth's axis, which affects how sunlight is distributed across the planet throughout the year, leading to variations in temperature and daylight.

What is a solar eclipse, and when does it occur?

• When the Moon is between the Earth and the Sun

• When the Earth is between the Sun and the Moon

• When the Sun is between the Earth and the Moon

• When the Moon is behind the Earth

Answer explanation

A solar eclipse occurs when the Moon is positioned directly between the Earth and the Sun, blocking the Sun's light. This alignment is what defines a solar eclipse, making the first answer choice correct.