Across
1
Absolute temperature scale unit
4
Unit of energy
5
Magnetic metallic element
6
Icy body with a tail near the sun
7
Preserved remains of ancient life
10
Tectonic landmass section
11
Biological catalyst
12
Tissue that contracts for movement
Down
2
Compound containing oxygen
3
Blocking of light by a celestial body
8
Naturally occurring inorganic solid
9
Curved glass that refracts light
13
Hottest planet in solar system