Across
1
Natural satellite of Earth
3
Unit of energy
5
Blocking of light by a celestial body
6
Precious yellow metallic element
9
Ball of burning gas in space
10
Infectious microscopic agent
11
Icy body with a tail near the sun
Down
2
Gas essential for breathing
4
Compound containing oxygen
7
Form of thermal energy
8
Positive particle in nucleus
12
Solid with repeating atomic pattern