Moon
What is Earth's only natural satellite
the moon
During what type of eclipse is the moon passing directly between the Earth and the sun, blocking the sun's light?
solar eclipse
The spinning of Earth on its axis is called?
rotation
The sun is a type of this gas sphere that gives off light and heat.
star
What are the rise and fall of ocean water that occur approximately every 12.5 hours?
tides
The side of the moon that always faces the earth is called the what?
the near side
During what type of eclipse is the Earth directly between the moon and the sun?
lunar eclipse
What is the movement of one object around another?
revolution
What is round, orbits the sun, and has cleared out the region of the solar system along its orbit?
What law states that every object in the universe attracts every other object?
Law of Universal Gravitation
The different shapes of the moon are called what?
phases
Why don't eclipses occur every month?
the plane of the moon's orbit around Earth is off by about 5 degree from the plane of Earth's orbit around the sun
How long does it take the Earth to revolve around the sun?
365.25 days
What are areas on the sun where plasma is cooler than the plasma around them?
sunspots
Why do we only see one side of the moon?
a "day" on the moon is the same length as a "year" on the moon
During what phase is the moon between the Earth and the sun?
new moon phase
During an eclipse, the very darkest part of the shadow where the light fom the sun is completely blocked is the?
umbra
How long does it take the Earth to rotate on its axis?
24 hours/1 day
A star's ______________ brightness is the brightness as seen from Earth.
apparent
Absolute brightness is the brightness the star would have if it were at a standard distance from Earth.
What occurs when either the Northern or Southern Hemisphere is at its strongest tilt toward teh sun?
solstice
How long does it take the moon to completely orbit the Earth?
Earth has what because its axis is tilted as it revolves around the sun?
seasons
What is a group of single stars, star systems, star clusters, dust and gas bound together by gravity?
galaxy
The gravitiational pulls from both the sun and moon combine to produce a tide with the most significatn difference bewteen consecutive low and high tides and is called what?
spring tide