Across
1
The Red Planet
3
Path of a planet around the sun
4
Push or pull on an object
5
Naturally occurring inorganic solid
7
Ball of burning gas in space
10
Blocking of light by a celestial body
Down
2
Group of similar cells
4
Preserved remains of ancient life
6
Unit of electric potential
8
Unit of heredity
9
Substance with pH below 7
10
Our home planet
11
Smallest unit of an element