1.
the study of space & everything in it
2.
the layer of gas that surrounds Earth
3.
the 6th element & chemical basis for life
4.
a small, icy object from the outer part of the solar system
5.
a pure substance containing only one type of atom
6.
state of matter where molecules are free to move around
7.
a process by which atoms are squeezed together under intense heat & pressure
8.
a fluid state of matter in which atoms move in a random motion
9.
a zone around a star where temperatures are just right
10.
the region in the solar system beyond the orbit of Neptune
11.
the distance a beam of light can travel through space in one Earth year
12.
a fluid state of matter
13.
a stony or metallic object from space that lands on Earth's surface
14.
a place for observing & studying objects in space
15.
a path followed by an object under the influence of gravity
16.
an object that orbits the sun & is big enough to have gravity
17.
an unmanned spacecraft sent outside of Earth's orbit to gather information
18.
a celestial body of gas that generates light & heat
19.
an instrument that uses lenses &/or mirrors to view distant objects
20.
a scientific explanation that is supported by experimental evidence
