Across
1
The Red Planet
4
Compound containing oxygen
5
Blocking of light by a celestial body
8
Particle of light
9
Magnetic metallic element
11
Force that attracts objects together
Down
2
Glass that splits light into spectrum
3
Group of similar cells
5
Biological catalyst
6
Icy body with a tail near the sun
7
Gas essential for breathing
10
Second lightest element