Across
1
The Red Planet
3
Biological catalyst
5
Absolute temperature scale unit
6
Path of a planet around the sun
10
Smallest unit of an element
12
Gas essential for breathing
13
Unit of power
Down
2
Solid with repeating atomic pattern
4
Unit of force
7
Ball of burning gas in space
8
Push or pull on an object
9
Tissue that contracts for movement
11
Icy body with a tail near the sun