The Milky Way Over the Arizona Toadstools
David Lane &
R. Gendler (3 insets)
Which is older -- the rocks you see on the ground or the light you see
from the sky?
Usually it's the rocks that are older, with their origin sediments
deposited well before light left any of the stars or nebulas you see in
the sky.
However, if you can see, through a telescope, a distant galaxy far
across the universe -- further than
Andromeda or spiral galaxy
NGC 7331 (inset) -- then you are seeing light even more ancient.
Featured here, the central disk of our
Milky Way Galaxy arches over Toadstool
hoodoos rock formations in northern
Arizona,
USA.
The unusual Toadstool rock caps
are relatively hard
sandstone
that wind has eroded more slowly than the softer sandstone underneath.
The green bands are
airglow, light emitted by the stimulated air in
Earth's atmosphere.
On the lower right is a time-lapse camera set up to capture the
sky rotating behind the picturesque foreground scene.