Astronomy Definitions
Planets
Gravity and Motion
The Moon
This and That
100
An oval shape: it may be elongated or nearly circular.
ellipse
100
This planet is closest to the sun.
Mercury
100
____________ attracts all objects toward each other.
gravity
100
The phase of the moon you see depends on how much of the moon's ________ side faces Earth.
sunlit
100
Earth has seasons because its axis is _______ as it revolves around the sun.
tilted
200
The region in the solar system between Mars and Jupiter where many asteroids are found.
asteroid belt
200
This planet is reddish in color and has polar ice caps. It is the 4th planet from the sun.
Mars
200
You are riding the bus home from school when it stops suddenly. You are thrown forward. This is an example of ____________.
inertia
200
This occurs when the moon passes directly between Earth and the sun.
solar eclipse
200
These are caused by the moon's gravitational pull on Earth.
tides
300
A small rock in space that is too small to be considered a planet.
asteroid
300
Which planet rotates almost completely on it's side?
Neptune
300
Name the two factors that combine to keep Earth in orbit around the sun and the moon in orbit around Earth.
inertia and gravity
300
Which phase of the moon occurs during a solar eclipse?
new moon
300
Earth moves through space in two ways. What are they?
rotation and revolution
400
A meteoroid that passes through the atmosphere and hits Earth's surface.
meteorite
400
Which planet is so massive that it's gravity keeps 66 moons orbiting around it?
Jupiter
400
An object at rest remains at rest and an object in motion remains in motion, unless acted upon by a force.
Newton's First Law of Motion
400
Which phase of the moon occurs during a lunar eclipse?
full moon
400
The path the moon takes as it revolves around Earth is called its _________.
orbit
500
The average distance between the Earth and sun, or approximately 150,000,000 km.
astronomical unit
500
Because the inner planets have solid surfaces, they are also called _______________ planets.
terrestrial
500
The strength of gravity depends on ___________________.
the masses of the objects and the distance between them.
500
When the Earth comes between the sun and moon, it's shadow blocks sunlight from reaching the moon.
lunar eclipse
500
When observed from Earth, celestial objects have an apparent circular motion in the sky from ______ to ______.
east to west
M
e
n
u