Across
1
Icy body with a tail near the sun
4
Substance with pH above 7
5
Blocking of light by a celestial body
6
Element found in all living things
7
Compound containing oxygen
11
Preserved remains of ancient life
Down
2
Center of an atom or cell
3
Unit of force
8
Gas form of a liquid
9
Curved glass that refracts light
10
Tectonic landmass section