The Eagle Nebula
Here is the final, fully processed photograph that NASA released
in 1995. Now, what does the image tell us about what we're seeing?
Basically we're looking at dense clouds of molecular hydrogen gas
and dust that form just one part of the Eagle Nebula. This is a
large area: from top to bottom, the pillar at left extends about
four light-years, or the distance light travels in four years
going at roughly 186,000 miles per second!
Parts of the clouds, particularly the finger-like projections you
can see at various points along the pillars, are dense enough to
collapse under their own weight, forming young stars. These
embryonic stars continue growing as long as they can draw mass
from the surrounding clouds. But ultraviolet light from massive
newborn stars (unseen off the top edge of the picture) is eating
away at the pillars, essentially evaporating the gas in these
clouds. Such "photoevaporation" gives shape to the pillars and
illuminates the fog of gas burning off their edges.
If you could go back 4.5 billion years and watch as our sun and
solar system formed, you would probably see a region very much
like what you see in the Eagle Nebula today. There's a lot more
science having to do with understanding the detailed physics of
the gas and what images like this tell us about how stars form.
But now you have at least a rough idea of both what we're learning
from this single snapshot from the Hubble Space Telescope and what
it takes to produce all those gorgeous images taken in orbit. For
more on how the Hubble works, see the official Hubble Web site at
http://hubblesite.org.