Across
1
Icy body with a tail near the sun
5
Preserved remains of ancient life
7
Disturbance that transfers energy
10
Absolute temperature scale unit
11
Second lightest element
Down
2
Substance with pH below 7
3
Natural satellite of Earth
4
Path of a planet around the sun
6
Naturally occurring inorganic solid
8
Blocking of light by a celestial body
9
Measure of matter in an object