Across
1
Amplified beam of light
3
Preserved remains of ancient life
4
The Red Planet
5
Center of an atom or cell
Down
2
Gas form of a liquid
4
Tissue that contracts for movement
6
Infectious microscopic agent
7
Substance with pH below 7
8
Ball of burning gas in space
9
Mass per unit volume
10
Blocking of light by a celestial body