Across
1
The Red Planet
2
Preserved remains of ancient life
3
Hottest planet in solar system
5
Substance with pH below 7
7
Natural satellite of Earth
9
Absolute temperature scale unit
Down
2
Push or pull on an object
4
Ball of burning gas in space
6
Compound containing oxygen
8
Group of similar cells
10
Second lightest element
11
Path of a planet around the sun