MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Jane Platt
FOR IMMEDIATE RELEASE
May 7, 1999
STAR-STUDDED PHOTO ALBUM DELIVERED TO INTERNET
A colossal assortment of star-studded, galaxy-filled
pictures and information - enough to fill the hard disks on
hundreds of home computers - is contained in the first major data
release from a telescope sky survey sponsored by NASA and the
National Science Foundation.
"We've posted a cornucopia of images on the Internet for
average home computer users as well as professional astronomers,"
said Dr. Michael Skrutskie, principal investigator of the survey,
designed to catalog 1 million galaxies, 300 million stars, and
other celestial objects. The collection includes up-and-comers
like T Tauri, an infant star, and stellar has-beens like the Crab
Nebula (the remnant of an exploding former star).
This early data sampling includes 230,000 pictures derived
from 3 million raw images, taken by a pair of 1.3-meter (51-inch)
telescopes near Tucson, AZ, and at Cerro Tololo, Chile. This
first sample represents just 6 percent of the anticipated final
database of the Two-Micron All-Sky Survey (2MASS). The telescopes
study near-infrared wavelengths not visible to the naked eye. By
sensing heat, they detect heat-emitting objects like stars and
galaxies that hide behind curtains of cold dust throughout our
Milky Way galaxy.
"Because the Milky Way is very dusty, we know very little
about how it's put together. It's like living in a city where
there's a constant dust storm and you have no idea what roads,
mountains and buildings are beyond your own house," Skrutskie
said. "Our sky survey helps us see through the dust to get a
clearer view of the Milky Way."
"We live inside the Milky Way Galaxy, which is shaped like a
flattened disk with embedded gas and dust," explained Dr. Roc
Cutri, 2MASS project scientist. "With visible light, dust limits
our view along the flattened disk. But near-infrared light is
less affected by dust, exposing many galaxies outside the Milky
Way that would otherwise be hidden."
2MASS, based at the University of Massachusetts, Amherst,
where Skrutskie is a physics and astronomy professor, is two
years into a three-and-a-half year survey of the entire sky.
One of the survey's most significant findings is the
definition of a class of stars called L-dwarfs, the coolest stars
known. "It's the first new classification of this type in nearly
a century," Cutri said. "We knew L-dwarfs existed, but 2MASS
established the category definitively. These may be the most
common stars in our galaxy or maybe the universe."
Cutri is affiliated with the JPL/Caltech Infrared Processing
and Analysis Center, which combines and processes 2MASS images
into usable data. The raw, unprocessed data contained in this
current batch fills more than one terabyte, or 1,000 gigabytes,
of computer memory. The average home computer contains less than
10 gigabytes of storage. Thanks to the Internet, people can
browse individual pictures without downloading the entire
database and gobbling up their computer memory.
Additional releases are planned every six months through the
end of 2000. With these images and catalogs, astronomers can
pinpoint positions and brightness of stars and other objects, and
determine sizes and shapes of galaxies and nebulae. They can then
choose specific objects for further study.
"We count the dots, so to speak, to study how galaxies are
scattered in the nearby universe," Skrutskie said. "The texture
of this distribution echoes how material was hurled about and
eventually settled into galaxies and stars after the Big Bang."
2MASS, part of NASA's Origins Program, is funded by NASA's
Office of Space Science and the National Science Foundation.
2MASS results will benefit future Origins missions, including
Space Infrared Telescope Facility and the Next Generation Space
Telescope. JPL manages the program for NASA's Office of Space
Science, Washington, DC. JPL is a division of the California
Institute of Technology, Pasadena, CA.
The current data release is available at the following
website:
May 7, 1999