___________ waves are a type of mechanical waves, and therefore, they cannot travel through empty space and matter.

The _____________________ travels at 300,000 km/s in a vacuum.

In a _____________ telescope, light passes through double convex lenses.

Because the Hubble Space Telescope uses concave mirrors, it is a good example of a ________________ type of telescope.

The moon is an example of a/an ______________ satellite of Earth.

A/an _________________ satellite is one that is built and launched by humans.

A ______________ has at least one burning chamber and a nozzle.

Which of the following choices is a list of natural satellites?

Which of the following is an example of an artificial of an artificial satellite?

The _____________________ has living quarters, work and exercise areas, and important science labs where scientists can work while in space.

When the moon moves between the Earth and the Sun and you can't see the Sun for a while, there is a ____________________.

When the moon moves behind the Earth and Earth casts its shadow on the moon there is a _______________________.

Earth is a ______________, which is a round, three-dimensional object.

The imaginary line around which Earth spins is called a/an ___________.

Earth's yearly orbit around the Sun is called its ____________________.

In the northern hemisphere, the ___________________ occurs on June 21 or 22. It is the longest day of the year.

When ALL of the moon's surface that faces Earth is lit up, there is a _________________________.

The phase of the moon that immediately precedes the new moon is the _____________________.

Which phase of the moon displays to the Earth more light?

____________ are dark colored, flat regions on the surface of the moon.

The ____________ is the smaller, darker shadow of an eclipse.

It takes the moon approximately one _____________ to complete a moon cycle (from a new moon to the next new moon.)

______________ was the first artificial satellite launched into space.

_______________ was the first mission to land a man on the moon.

It is the _____________ of the Earth that causes seasons.

The phases of the moon where more and more of the lighted part of the moon is visible each night until you see a full moon it called the ____________ ______________.

The spinning of Earth on its axis causing day and night is called Earth's ____________________.

Which president gave a speech at Rice University that challenged the U.S. as a nation to "go to the moon in this decade."

The nick name used to describe the competitive drive for technology between Russia and the United States in the early 1960s is the ___________________.