Blu
Sun’s light
Red light
A
t h g e li
u
Atmosphere
y l
Ra
e i g h
s c a
t t e r i n g
N
C
Ar
O
O O
N
Ar
O
N
Ar Ar
N
N
C
O O
N
A
Power Lines
Combustion Engine Exhaust Factories
Petroleum
Air pollution
Fertilizer Dust
Radioactive Fallout