Across
1
Blocking of light by a celestial body
5
Path of a planet around the sun
6
Infectious microscopic agent
7
Magnetic metallic element
8
Curved glass that refracts light
10
Fourth state of matter
12
Disturbance that transfers energy
Down
2
Unit of electric potential
3
Group of similar cells
4
Tissue that contracts for movement
9
Center of an atom or cell
11
Icy body with a tail near the sun