Across
1
Particle of light
5
Solid with repeating atomic pattern
6
Gas essential for breathing
8
Mass per unit volume
10
Form of thermal energy
11
Amplified beam of light
Down
2
Unit of power
3
Blocking of light by a celestial body
4
Absolute temperature scale unit
5
Icy body with a tail near the sun
7
Ball of burning gas in space
9
Preserved remains of ancient life