“Remarkable, breathtaking” are words jubilant
astronomers are using to describe the first four views of the
universe taken by the Hubble Space Telescope’s new Advanced
Camera for Surveys, released by NASA today.
The new camera was installed on Hubble by astronauts during a
shuttle mission last March, the fourth Hubble Space Telescope
servicing mission. During five of the most challenging
spacewalks ever attempted, the crew successfully upgraded the
orbiting telescope with the new camera, a new power unit, new
solar arrays and an experimental cooling unit for an infrared
camera. Hubble managers say the orbiting telescope has been
operating superbly since the servicing mission.
“Today marks the beginning of a new era of exploration with
Hubble,” said Dr. Ed Weiler, Associate Administrator for
Space Science at NASA Headquarters, Washington. “Our team of
scientists and engineers on the ground and the astronauts in
space once again did the impossible. After 12 years in space,
Hubble not only was given a major overhaul, its new camera
has already shown us that, even after 12 years of great
science and astounding images, we haven’t seen anything yet.”
Among the suite of four “suitable-for-framing” Advanced
Camera for Surveys (ACS) science-demonstration pictures
released today is a stunning view of a colliding galaxy,
dubbed the “Tadpole,” located 420 million light-years away.
Unlike textbook images of stately galaxies, the “Tadpole” —
with a long tail of stars — captures the essence of a
dynamic, restless and violent universe, looking like a
runaway pinwheel firework.
“The ACS is opening a wide new window onto the universe.
These are among the best images of the distant universe
humans have ever seen,” said astronomer Holland Ford of Johns
Hopkins University in Baltimore, lead scientist in the
camera’s seven-year development.
The camera’s tenfold increase in efficiency will open up much
anticipated new capability for discovery. “ACS will allow us
to push back the frontier of the early universe. We will be
able to enter the ‘twilight zone’ period when galaxies were
just beginning to form out of the blackness following the
cooling of the universe from the big bang,” said Ford.
The ACS is a camera of superlatives. It is expected to
surpass the sensitivity of the largest ground-based telescope
to eventually see the very faintest objects ever recorded.
The camera delivers a panoramic crispness comparable to that
of a wide-screen movie, containing 16 million picture
elements (megapixels) per image. By comparison, digital
photos from typical consumer cameras are 2 to 4 megapixels.
The ACS image of the Tadpole illustrates the dramatic gains
over the Wide Field Planetary Camera 2 resulting from
doubling the area and resolution, and demonstrates a five-
fold improvement in sensitivity. An unexpected bonus is the
enormous number of galaxies in the new Hubble image beyond
the Tadpole galaxy, giving it an appearance like the galaxy-
filled Hubble Deep Field (HDF) image, taken in 1995. However,
the ACS picture was taken in one-twelfth the time it took for
the original HDF. Like the Hubble Deep Field, the ACS
galaxies contain myriad shapes that are snapshots of galaxies
throughout the universe’s 13 billion-year evolution. The ACS
images are so sharp astronomers can identify “building
blocks” of galaxies, colliding galaxies and extremely distant
galaxies in the field — an exquisite sampler of galaxies.
“The ACS will let us obtain the deepest image of the universe
for the foreseeable future,” added astronomer Garth
Illingworth of the University of California, Lick
Observatory, Santa Cruz, the deputy leader for the camera
team.
The other pictures include a stunning collision between two
spiral galaxies, dubbed “the Mice,” that presage what might
happen to our own Milky Way several billion years in the
future when it collides with the neighboring galaxy in the
constellation Andromeda. Computer simulations show that we
are seeing the collision of the Mice approximately 160
million years after their closest encounter. Running the
simulations forward in time shows that the two galaxies will
eventually merge. A similar fate may await the Milky Way and
the Andromeda galaxy.
Looking closer to home, ACS imaged the “Cone Nebula,” a
craggy-looking mountaintop of cold gas and dust that is a
cousin to Hubble’s iconic “pillars of creation” in the Eagle
Nebula, photographed in 1995.
Peering into a celestial maternity ward called the M17 Swan
Nebula, the ACS revealed a watercolor fantasy-world tapestry
of vivid colors and glowing ridges of gas. Embedded in this
crucible of star creation are embryonic planetary systems.
In addition to the ACS, spacewalking astronauts installed a
new high-tech mechanical “refrigerator” on Hubble during the
servicing mission. This “cryocooler” has successfully pumped
most of the heat out of the interior of the Near Infrared
Camera and Multi-Object Spectrometer (NICMOS), achieving and
maintaining to within a few hundredths of one degree the
target temperature for neon gas passing through the
instrument of 70 degrees Kelvin (minus 203 degrees Centigrade
or minus 333 degrees Fahrenheit).
Engineers are now in the process of checking out the
operation of the resuscitated NICMOS instrument. By early
June, scientists expect to release the first astronomical
images taken with the NICMOS since 1998, when it was still
being cooled by a rapidly depleting block of solid nitrogen
ice.
The new rigid solar arrays, working with the new Power
Control Unit, are generating 27 percent more electrical power
than the previous arrays. This doubles the electrical power
that can be allocated to the scientific instruments on
Hubble. The new reaction wheel is operating normally. Nearly
a month ago, the Space Telescope Imaging Spectrograph and the
Wide Field and Planetary Camera 2 resumed science
observations.
“This servicing mission has turned out to be an extraordinary
success,” said Preston Burch, Hubble Project Manager at
NASA’s Goddard Space Flight Center in Greenbelt, Md. “It was
the most difficult and complicated Hubble servicing mission
attempted to date and our
observatory came through it with flying colors.”
-end-
Electronic image files, animation and additional information
are available on the Internet at:
http://oposite.stsci.edu/pubinfo/pr/2002/11
http://oposite.stsci.edu/pubinfo/latest.html
http://oposite.stsci.edu/publinfo/pictures.html
and
