The Moon: phases, tides, and features

The moon revolves around Earth. The moon travels at a speed of about 1 km/s. Which of the following keeps the moon in orbit around Earth?

• gravity
• magnetism
• ocean tides
• sun nuclear fusion

Sometimes the moon looks like a crescent. At other times, the moon looks like a half circle. What makes it possible for you to see the surface of the moon from Earth?

• The moon gives off its own light.
• Light from Earth is reflected by the moon’s surface. 
• Light from the sun is reflected by the moon’s surface.
• The moon absorbs sunlight during the day and glows at night.

A satellite is an object that revolves around a larger object. Many satellites are orbiting Earth. Which of the following is an important factor in keeping a communications satellite in orbit around Earth?

• gravitiy
• heat
• light 
• magnitism

Each lunar cycle has one full moon, in which the relative positions of Earth, the sun, and the moon form in a straight line. Which list represents the position of Earth, the sun, and the moon during a full moon?

• Earth, sun, moon
• sun, moon, Earth
• moon, sun, Earth
• sun, Earth, moon

Just as Earth moves around the sun, the moon revolves around Earth. About how many Earth days does it take for the moon to travel around Earth?

• about 7 days

• about 28 days

• about 180 days

• about 365 days

The phases of the moon are the regular changes in how the moon looks from Earth. In which phase is the moon not visible from Earth?

• new moon
• waxing gibbous
• waxing crescent
• waning crescent

Eclipses are predictable, solar system events. The answer choices below list relative positions of Earth, the sun, and the moon. Which list represents the position of Earth, the sun, and the moon during a lunar eclipse?

• Earth, sun, moon
• sun, Earth, moon 
• sun, moon, Earth
• moon, sun, Earth 

Augustine observes the moon every 3 days for 15 days. He notices that over this 15-day period, the moon looks different. What accounts for the differences in the appearance of the moon over this time period?

• the speed of the moon’s orbit

• the position of Augustine on Earth

• the distance between Earth and the moon

• the position of the moon in its orbit around Earth

Once a month, Earth passes directly between the moon and the sun. Is a solar eclipse possible during this time?

• Yes, because new moons happen when Earth is between the moon and the sun, and solar eclipses happen only during new moons.
• No, because new moons happen when Earth is between the moon and the sun, and solar eclipses happen only during full moons.
• Yes, because full moons happen when Earth is between the moon and the sun, and solar eclipses happen only during full moons.
• No, because full moons happen when Earth is between the moon and the sun, and solar eclipses happen only during new moons

The phases of the moon are the changing appearances of the moon, as seen from Earth. Which solar system event can happen only during a full moon?

• a new moon
• a solar eclipse
• a lunar eclipse
• a waning gibbous