FOR RELEASE: November 20, 1995

PHOTO NO.: STScI-PRC95-45a


CRUCIBLE OF CREATION: PANORAMIC HUBBLE MOSAIC ZOOMS IN 
ON MAELSTROM OF STAR BIRTH

This spectacular color panorama of the center the Orion nebula is one
of the largest pictures ever assembled from individual images taken
with NASA's Hubble Space Telescope.  The picture, seamlessly composited
from a mosaic of 15 separate fields, covers an area of sky about five
percent the area covered by the full Moon.

The seemingly infinite tapestry of rich detail revealed by Hubble shows
a churning turbulent star factory set within a maelstrom of flowing,
luminescent gas.  Though this 2.5 light-years wide view is still a
small portion of the entire nebula, it includes almost all of the light
from the bright glowing clouds of gas and a star cluster associated
with the nebula.  Hubble reveals details as small as 4.1 billion miles
across.

Hubble Space Telescope observing time was devoted to making this
panorama because the nebula is a vast laboratory for studying the
processes which gave birth to our own Sun and solar system 4.5 billion
years ago.  Many of the nebula's details can't be captured in a single
picture - any more than one snapshot of the Grand Canyon yields clues
to its formation and history.  Like the Grand Canyon, the Orion nebula
has a dramatic surface topography -- of glowing gasses instead of rock
-- with  peaks, valleys and walls.  They are illuminated and heated by
a torrent of energetic ultraviolet light from its four hottest and most
massive stars, called the Trapezium, which lie near the center of the
image.

In addition to the Trapezium, this stellar cavern contains 700 hundred
other young stars at various stages of formation.  High-speed jets of
hot gas spewed by some of the infant stars send supersonic shock waves
tearing into the nebula at  100,000 miles per hour.  These shock waves
appear as thin curved loops, sometimes with bright knots on their end
(the brightest examples are near the bright star at the lower left).

The mosaic reveals at least 153 glowing protoplanetary disks (first
discovered with the Hubble in 1992, and dubbed "proplyds") that are
believed to be embryonic solar systems that will eventually form
planets.  (Our solar system has long been considered the relic of just
such a disk that formed around the newborn Sun).  The abundance of such
objects in the Orion nebula strengthens the argument that planet
formation is a common occurrence in the universe.  The proplyds that
are closest to the Trapezium stars (image center) are shedding some of
their gas and dust.  The pressure of starlight from the hottest stars
forms "tails" which act like wind vanes pointing away from the
Trapezium.  These tails result from the light from the star pushing the
dust and gas away from the outside layers of the proplyds.  In addition
to the luminescent proplyds, seven disks are silhouetted against the
bright background of the nebula.  These dark objects allow Hubble
astronomers to estimate the masses of the disks as at least 0.1 to 730
times the mass of our Earth.

Located 1,500 light-years away, along our spiral arm of the Milky Way,
the Orion nebula is located in the middle of the sword region of the
constellation Orion the Hunter, which dominates the early winter
evening sky, at northern latitudes.  The stars have formed from
collapsing clouds of interstellar gas within the last million years.
The most massive clouds have formed the brightest stars near the center
and these are so hot that they illuminate the gas left behind after the
period of star formation was complete.  The more numerous faint stars
are still in the process of collapsing under their own gravity, but
have become hot enough in their centers to be self luminous bodies.

Technical information:  To create this color mosaic, 45 separate images
of the Orion nebula were taken in blue, green and red between January
1994 and March 1995.  Light emitted by oxygen is shown as blue,
hydrogen emission is shown as green, and nitrogen emission as red
light.  The overall color balance is close to that which an observer
living near the Orion nebula would see.  The irregular borders produced
by the HST images have been smoothed out by the addition of images from
the European Southern Observatory in Chile obtained by Bo Reipurth and
John Bally, these being about 2% of the area shown here and lying at
the top left corner.

Credit:  C.R. O'Dell (Rice University), and NASA