Across
1
Form of thermal energy
3
Infectious microscopic agent
5
Substance with pH below 7
6
Path of a planet around the sun
7
Icy body with a tail near the sun
11
Our home planet
Down
2
Positive particle in nucleus
4
Blocking of light by a celestial body
8
Substance with pH above 7
9
The Red Planet
10
Naturally occurring inorganic solid