Across
1
Icy body with a tail near the sun
4
Second lightest element
6
Fourth state of matter
10
Curved glass that refracts light
Down
1
Element found in all living things
2
Particle of light
3
The Red Planet
5
Force that attracts objects together
7
Chemical element in table salt
8
Our home planet
9
Blocking of light by a celestial body