This animation transitions from the more familiar visible light
image of the "Whirlpool Galaxy" to the dramatic new view
captured by NASA's Spitzer Space Telescope. Revealed are strange
structures bridging the gaps between the dust-rich spiral arms,
and tracing the dust, gas and stellar populations in both the
bright spiral galaxy and its companion. The visible light image
comes from the Kitt Peak National Observatory 2.1m telescope,
and is a four-color composite showing light from 0.4 to 0.7
microns, including the H-alpha nebular feature (red in the
image). The Spitzer image is a four-color composite of invisible
light of wavelengths of 3.6 microns (blue), 4.5 microns (green),
5.8 microns (orange) and 8.0 microns (red). These wavelengths
are roughly 10 times longer than those seen by the human eye.
The light seen in the images originates from very different
sources. At shorter wavelengths (in the visible bands, and in
the infrared from 3.6 to 4.5 microns), the light comes mainly
from stars. This starlight fa