Across
1
Blocking of light by a celestial body
3
Gas form of a liquid
6
Icy body with a tail near the sun
8
Second lightest element
10
Amplified beam of light
11
Force that attracts objects together
Down
1
Our home planet
2
Ball of burning gas in space
4
Fourth state of matter
5
Chemical element in table salt
7
Path of a planet around the sun
9
Nerve cell in the brain
12
Disturbance that transfers energy
13
Substance with pH below 7