What does the universe look like through
infrared goggles?
Our eyes can only see
visible light,
but astronomers want to see more.
Today’s APOD shows
spiral galaxy
IC 5332
as seen by two
NASA
telescopes:
Webb in
mid-
infrared
and
Hubble in
ultraviolet
and visible light.
To toggle between the two space-based views just follow
this link).
The Hubble image highlights the
spiral arms
of the galaxy separated by
dark
regions, whereas the Webb image reveals a finer, more tangled structure.
Interstellar dust
scatters and absorbs light from the stars in the galaxy,
causing the
dark dust lanes
in the Hubble image, and then emits heat in infrared light, so dust
glows
in this Webb image.
The
Mid-InfraRed Instrument
on Webb needs to operate at a chilling temperature of
-266ºC (or - 447ºF), otherwise it would detect infrared radiation from
the telescope itself.
Combining
these observations,
astronomers
connect the “small scale” of gas and stars to the truly large scale of
galactic structure and evolution.