Across
1
Element found in all living things
3
Unit of energy
5
Form of thermal energy
7
Ball of burning gas in space
8
Unit of heredity
11
Blocking of light by a celestial body
Down
1
Icy body with a tail near the sun
2
Hottest planet in solar system
4
Molten rock beneath Earth surface
6
Center of an atom or cell
9
Path of a planet around the sun
10
Naturally occurring inorganic solid
12
Amplified beam of light