Across
1
Amplified beam of light
4
Path of a planet around the sun
5
Blocking of light by a celestial body
9
Second lightest element
10
Glass that splits light into spectrum
11
Naturally occurring inorganic solid
12
Positive particle in nucleus
13
Magnetic metallic element
Down
2
Force that attracts objects together
3
Group of similar cells
6
Tissue that contracts for movement
7
Curved glass that refracts light
8
Unit of force