Across
1
Icy body with a tail near the sun
3
Substance with pH above 7
7
The Red Planet
8
Curved glass that refracts light
9
Magnetic metallic element
11
Blocking of light by a celestial body
Down
1
Basic unit of life
2
Path of a planet around the sun
4
Chemical element in table salt
5
Biological catalyst
6
Form of thermal energy
10
Solid with repeating atomic pattern