Across
1
Natural satellite of Earth
3
Particle of light
4
Absolute temperature scale unit
8
Gas essential for breathing
9
Blocking of light by a celestial body
10
Nerve cell in the brain
Down
2
Preserved remains of ancient life
3
Positive particle in nucleus
5
Curved glass that refracts light
6
Unit of heredity
7
Solid with repeating atomic pattern