Across
1
Glass that splits light into spectrum
2
Solid with repeating atomic pattern
4
Ball of burning gas in space
7
Path of a planet around the sun
9
Hottest planet in solar system
10
Gas essential for breathing
12
Unit of heredity
Down
2
Icy body with a tail near the sun
3
Force that attracts objects together
5
The Red Planet
6
Blocking of light by a celestial body
8
Unit of energy
11
Biological catalyst