Name ____________________________________ Date ____________________________ Class________________

The Structure of the Solar SystemDirections: On each line, write the term from the word bank that correctly completes each sentence.

Some terms may be used more than once or not at all.

astronomical closer comet elliptical energy

farther faster foci focus gas giant

gravitational inner outer planet revolve

rotate slower solar system star Sun

The night sky offers a fascinating view into space. Most of the specks of light in the night sky

are (1.)________________________. They exist far beyond our (2.)________________________.

The largest object in our solar system is the (3.)________________________, which produces an

enormous amount of (4.)________________________. The Sun also applies a(n)

(5.)_________________ pull on the planets. When you look into the night sky, you might see light

reflected off a(n) (6.)____________________, such as Venus.

Objects in space (7.)_____________________ around the Sun along a stretched-out circle

called a(n) (8.)_____________________ orbit. Planets also (9.)________________________, or

spin. There are four (10.)___________________ planets that are made up mostly of solid rocky

materials. These objects are spherical and have a mass larger than the total mass of all other objects

whose orbits are nearby. There also are four (11.)_________________ planets made of gases,

including helium and hydrogen. These four planets are sometimes termed

(12.)__________________.

Distance in space is measured in (13.)______________________ units. A planet’s speed

changes as it obits the Sun. A planet that is close to the Sun moves (14.)______________________

than a planet that is far from the Sun. Also, planets that are (15.)___________________ from the

Sun have longer periods of revolution than planets that are closer to the Sun. The shape of a planet’s

orbit is determined by two (16.)___________________ points. These (17.)___________________

are equal distances from the center of the ellipse.