Across
1
Infectious microscopic agent
5
Path of a planet around the sun
7
Blocking of light by a celestial body
8
Fourth state of matter
9
Form of thermal energy
Down
2
Reddish electrical conductor
3
Amplified beam of light
4
Force that attracts objects together
6
Group of similar cells
10
Unit of electric potential
11
Nerve cell in the brain
12
Our home planet