Space and Space History Crossword

Italian astronomer and mathematician who was the first to use a telescope to study the stars
1st American in space
1st object to enter into Earth's orbit
1st human in space
1st American to orbit the earth
1st lunar landing of humans
A large satellite on which scientists conduct research and live
Oval shaped path where planets orbit the sun
The process inside stars in which two hydrogen atoms combine to create helium, releasing huge amounts of energy
Name given to the four solid planets closest to the sun
The name given to the four outer planets that do not have a solid surface
Region beyond the orbit of Neptune where many small space objects are found
One of the rocky objects orbiting the sun that are too small and too numerous to be considered a planet
A meteoroid that has made it through Earth's atmosphere and hit Earth's surface
Smallest terrestrial planet, closest to the sun
Hottest planet due to atmospheric gases
Only planet we know of that supports life
The Red Planet, home to Olympus Mons
Largest planet in our solar system
Planet with the widest rings
Outer planet that spins on its side
Farthest planet from the sun
Produces its own light
A force of attraction between objects that is due to their masses
A natural satellite that revolves around a planet
A large body in space that orbits a star and does not produce light of its own