Across
1
Path of a planet around the sun
3
Basic unit of life
4
Substance with pH above 7
6
Fourth state of matter
7
Icy body with a tail near the sun
10
Magnetic metallic element
12
Unit of power
Down
2
Blocking of light by a celestial body
5
Tissue that contracts for movement
8
Force that attracts objects together
9
Smallest unit of an element
11
Ball of burning gas in space