By what name is a quasi-stellar radio source better known?

What is the tilt of the earth as it rotates on its axis?

Who was the third person to walk on the moon?

What is Pluto's period of revolution around the sun?

Who described the rings of Saturn as "ears of a teacup"?

Who first proposed the heliocentric model of the solar system?

How many days in a Mercurian year?

What color of star has the hottest surface temperature?

What was the first probe to land on Venus?

How long does it take Mercury to rotate on its axis?

The Planting Moon is found in which month?

Who was the first African-American female astronaut?

What is the constellation known as the Ram also called?

What star, next to the Sun, is nearest to Earth?

What is Earth's nearest neighbor in space?

What fraction of Earth's gravity is the Moon's gravity?

How many stars make up Orion's Belt?

Which is the planet with the greatest average density?

What was the name of the first manned space vehicle?

Which is the slowest orbiting planet?

Which constellation represents a hunter with weapons?

What is the "disk" that encircles a black hole called?

What is the only moon in the solar system that has an atmosphere?

What is the sixth planet from the sun?

What satellite series was known as "fellow traveler"?