Infrared astronomy
is the detection, analysis, and study of infrared light
produced in our universe. Stars, galaxies, and other astronomical
sources (dust or gas) produce or reflect not only visible
light (what human eyes see), but also emit radiation in
other parts of the electromagnetic spectrum, including radio
waves, ultraviolet, gamma rays, or infrared. Astronomers
have developed tools to observe the universe in these sections
of the electromagnetic spectrum. Infrared is the range of
the electromagnetic spectrum between the visible and microwaves.
Material between -270 and -100 C is not hot enough to be
visible to human eyes. Nonetheless, it still emits infrared
radiation. There is plenty of material in the vast space
between stars in this temperature range; space is a very
cold place unless you are close to a star! Astronomers generally
use the term Interstellar Medium to refer to this material.
Infrared cameras can detect the distribution and structure
of this particularly cold matter in the universe. Observing
in the infrared allows astronomers to see and study regions
of the universe, which are mostly dark in the visible. Another
reason why astronomers prefer to make observations in the
infrared is that infrared radiation travels much longer
distances than visible light, which ‘gets lost’
(scattered) rather easily. Any particles that happen to
be in the line of sight have a much greater chance to absorb
visible rather than infrared light.
