Earth & Space Post-test

The correct order from smallest to largest is moon, earth, sun. The moon is the smallest celestial body among the three, followed by the earth which is larger, and the sun being the largest.

The explanation for the given correct answer is that the earth orbits around the sun and the moon orbits around the earth. This is a well-established fact in astronomy. The earth revolves around the sun in an elliptical orbit, taking approximately 365 days to complete one orbit. Meanwhile, the moon revolves around the earth in a similar elliptical orbit, taking about 27.3 days to complete one orbit. This arrangement of orbits is what causes phenomena like day and night, seasons, and lunar phases.

Earth's rotation is the correct answer because as the Earth spins on its axis, different parts of the planet are exposed to the Sun's light, creating day and night. This rotation takes approximately 24 hours to complete, resulting in the cycle of day and night that we experience on Earth. The other options, such as Earth's orbit or the moon's orbit and rotation, do not directly cause day and night on Earth.

The full moon occurs when the side of the moon facing the Earth is completely lit up, resulting in a fully illuminated view from Earth. On the other hand, the new moon happens when the side of the moon facing the Earth is completely dark, as it is not receiving any direct sunlight. The new moon phase marks the beginning of a new lunar cycle.

If the sun had no gravitational pull, the planets would no longer be held in their orbits around the sun. Without the sun's gravitational force, the planets would be free to move throughout the solar system in unpredictable paths.

The moon gets its light by reflecting light from the sun. This is why we see different phases of the moon as it orbits the Earth. When the moon is between the Earth and the sun, we see a new moon because the side of the moon facing us is not receiving any sunlight. As the moon moves in its orbit, we see different amounts of the sunlit side, resulting in the different phases of the moon. Therefore, the correct answer is that the moon reflects light from the sun.

A lunar eclipse occurs when the moon is hidden from sight because of the Earth's shadow. During a lunar eclipse, the Earth comes between the sun and the moon, causing the moon to pass through the Earth's shadow. This results in the moon appearing dark or reddish in color during the eclipse. The moon does not block the sun during a lunar eclipse, as it does in a solar eclipse.

The tilt of the Earth's axis and its orbit around the sun are the two factors that cause seasons on Earth. The tilt of the axis causes different parts of the Earth to receive varying amounts of sunlight throughout the year, resulting in the change of seasons. As the Earth orbits around the sun, the angle at which sunlight reaches different regions of the Earth changes, further influencing the seasons.

The moon's appearance changes because of its orbit around the Earth. As the moon moves in its orbit, different portions of its illuminated surface are visible from Earth, resulting in different phases such as full moon, crescent, or half moon. This change in perspective creates the illusion of the moon changing shape.

The Earth's gravity holds the moon in orbit around the Earth. Gravity is the force of attraction between two objects with mass, and the larger the mass, the stronger the gravitational pull. Since the Earth is much larger and more massive than the moon, its gravitational force is able to keep the moon in orbit. This force keeps the moon constantly moving around the Earth in a circular or elliptical path, balancing the moon's forward motion with the Earth's gravitational pull.

The sun's gravity has the ability to hold both planets and moons in orbit. Planets and moons are constantly pulled towards the sun due to its strong gravitational force, which keeps them in their respective orbits. Therefore, both options A and B are correct.

Gravity pulls things to the center because it is a force that attracts all objects towards each other. This force is proportional to the mass of the objects and inversely proportional to the square of the distance between them. Therefore, gravity pulls objects towards the center of the Earth or towards the center of any other massive object.