Across
1
Natural satellite of Earth
3
Icy body with a tail near the sun
5
Substance with pH below 7
6
Blocking of light by a celestial body
9
The Red Planet
12
Unit of electric potential
13
Group of similar cells
Down
2
Push or pull on an object
4
Measure of matter in an object
5
Smallest unit of an element
7
Tectonic landmass section
8
Fourth state of matter
10
Precious yellow metallic element
11
Unit of force