With help from an infrared-telescope-equipped satellite, NASA scientists will soon be able to set their eyes on the darkest reaches of outer space for the first time.
Set for launch no earlier than Friday from Vandenberg Air Force Base in California is the Wide-field Infrared Survey Explorer, a satellite that scientists say will bring to light never-before-seen asteroids, stars and less-luminous galaxies.
The 10-month, $30 million project - dubbed "WISE" - will photograph and survey the entire sky, creating a database of new information on previously undetected objects and provide increased detail about the already known.
"We will build up a pictorial atlas that can be used by research astronomers for decades to come," said Roc Cutri, a University of Arizona alumnus and lead scientist at the WISE Science Data Center at the California Institute of Technology. "It will be the 'Google Earth' of infrared space."
People are also reading…
Every object in the universe emits light radiation. The WISE telescope detects a range of this infrared radiation, finding dark objects that optical telescopes usually miss.
The amount of radiation an object gives off is dependent on its temperature, and the WISE telescope will see the glow of objects with temperatures between minus 330 Fahrenheit and 1,300 degrees Fahrenheit, according to a NASA press release.
The temperature range includes cool dust, dim stars, dusty galaxies and other objects normally left undetected.
The satellite will orbit Earth 15 times a day, taking snapshots every 11 seconds, amounting to about 7,500 images a day. Every position in the sky will be photographed at least eight times.
"To try and observe those objects from the ground is like trying to observe stars in visible light, in the daytime, with a luminous telescope," said Bob McMillan, an associate research scientist at the UA's Lunar and Planetary Laboratory and member of the WISE science team. "You have millions of times more sensitivity than you would on the ground."
McMillan arrived at the UA in 1980 and began the Spacewatch program - a group of scientists and engineers who study and explore populations of small objects in the solar system using the UA's Steward Observatory telescopes atop Kitt Peak. He was chosen to work as a ground-based observer of asteroids found by the WISE mission in 2001 and also serves as the lead scientist of Solar System Science for the mission.
When asteroids and other near-Earth objects of interest are detected, he and his team will conduct ground-based research on them from their operation on Kitt Peak, McMillan said.
While locating asteroids is incidental to the focus of the mission, which is to detect the most distant galaxies and nearby stars of low luminosity, the benefit of using the tool to identify these objects is of great importance, McMillan said.
Impacts happen today and are not something that happened only at some distant point in the past, McMillan said. But because impacts are rare and occur randomly, it's important to know where the bigger objects are as a precaution.
Congress currently funds ground-based surveys of objects of 1 kilometer, or nearly two-thirds of a mile, in diameter. Objects of that size would cause a global catastrophe if they were to strike Earth, sending clouds of debris high into the atmosphere, blocking the sun and killing the world's crops for at least two years, McMillan said.
It would not be an "extinction event," McMillan said. But civilization as we know it would be drastically disrupted.
Interest has been expressed by Congress to extend the identification of objects to those at least 460 feet in diameter, which are big enough to penetrate the Earth's atmosphere and cause significant damage.
For perspective, Meteor Crater near Flagstaff, which is about 4,000 feet in diameter and about 570 feet deep, is believed to have been made by an object about 100 to 160 feet in diameter.
The mission is the second of its kind. The first infrared survey of the whole sky was the Infrared Astronomical Satellite, launched in 1983. Findings from that mission are still being studied and published today.
WISE, with 100 times the sensitivity, will "dominate the rest of the century in the fields it influences," McMillan said.
The mission may possibly give us a peek at the faraway future of space travel.
"If we talk about the distant future - interstellar travel - it is possible that WISE will find a planetary system that will eventually be visited by spacecraft," McMillan said. "There will be a lot of science for a long time to come out of this."
Contact reporter Stephen Ceasar at 573-4142 or sceasar@azstarnet.com
