Astronomy Unit Part 2

The moon has a stronger influence on Earth's tides than the sun because the moon-

• is denser than the sun

• has more mass than the sun

• is much closer to Earth

• moves much faster relative to Earth

Which statement best explains why the same side of the Moon is viewed from Earth as the Moon goes through its phases?

• The Moon does not rotate as it revolves around Earth.

• The Moon’s period of rotation equals Earth’s period of rotation.

• The Moon’s period of rotation equals Earth’s period of revolution around the Sun.

• The Moon’s period of rotation equals the Moon’s period of revolution around Earth.

The diagram below shows Earth on a particular day in its orbit around the Sun. The dashed line represents Earth’s axis.

• June 21

• March 21

• September 21

• December 21

What event is shown in this diagram?

• summer solstice

• vernal equinox

• solar eclipse

• lunar eclipse

93 million miles, the average distance from the Earth to the sun, is a unit of measurement referred to as a (an)-

• parsec

• light year

• parallax

• astronomical unit (AU)

During a solar eclipse, the Moon is positioned between Earth and the Sun. During which phase of the Moon does a solar eclipse occur?

• gibbous
• new
• full
• crescent

When it is summer in the northern hemisphere of Earth, it is winter in the southern hemisphere. Which statement explains this fact?

• With more clouds in the winter, less sunlight can reach the surface of Earth.
• Earth is farther from the Sun in winter and closer to the Sun in summer.
• Since Earth is tilted on its axis, heat from the Sun gets distributed unequally.
• The Sun gives off more heat in the summer and less heat in the winter.

Why does the moon appear to change during the month?

• because the clouds in the sky hide the moon from Earth
• because the sun blocks the moon from Earth
• because the moon moves father away from Earth
• because the moon reflects sunlight as it rotates around Earth

How long does the Earth take to orbit or revolve once around the sun?

• day
• month
• week
• year

Which of these would be shorter if the Earth rotated faster?

• day
• month
• week
• year