Goddard's John Mather A Wise Guy

Dr. John Mather, Senior Astrophysicist in the Infrared Astrophysics Branch, was appointed as a Co-Investigator for the proposed Wide-field Infrared Survey Explorer (WISE) mission.

Mather is also Senior Project Scientist for the James Webb Space Telescope (JWST), an infrared telescope that will be the largest ever in space, and will explore the deep space frontier beyond what the Hubble Space Telescope can observe. He feels perfectly suited to his new role as a WISE Co-Investigator because the two missions will complement each other.

"WISE will survey the entire infrared sky with unprecedented sensitivity, finding many new and interesting objects for a closer look by JWST," said Mather. He was the Project Scientist for Goddard's Cosmic Background Explorer (COBE), which at the time provided the most detailed map of the infrared afterglow from the Big Bang, and has extensive experience observing celestial objects that emit infrared light, which is invisible to the human eye but detectable by special instruments.

"I'll share technical information where appropriate; for example, I'm making sure the WISE team is aware of the detector technology developed for JWST, so they can take advantage of our advances," said Mather.

If approved and it proceeds on schedule, WISE could be launched near the end of 2007 for a planned six-month mission. (JWST is expected to launch in 2010.) Once in orbit, WISE will make an all-sky infrared survey up to 1,000 times more sensitive than previous surveys.

In addition to picking targets for JWST, WISE is expected to find the brightest galaxies in the universe, which are often cloaked behind veils of dust. Since these galaxies emit as much as 100 times more infrared light than visible light, and since infrared light can pass through dust without being scattered as much as visible light, WISE can reveal them.

WISE could also find the closest stars to the Sun; faint, tiny objects called "Brown Dwarfs". They are also known as failed stars, since they are not massive enough to shine by nuclear fusion in their core, like typical stars. Instead, they glow mostly in infrared with the heat left over from their formation. These low mass stars are expected to be more numerous than the more massive stars like red dwarfs, and thus there should be brown dwarf stars closer to the Solar system than Proxima Centauri, the closest known ordinary star.

Asteroid hunting will also be in WISE's job description. Asteroids are usually detected optically, but the typical asteroid is quite dark and usually absorbs ten times more solar radiation than it reflects. The absorbed power goes into heating the asteroid, and this heat is then radiated away as infrared radiation. As a result, WISE will be able to detect asteroids a million times fainter than Ceres, the largest asteroid. These faint, small asteroids are not well catalogued, so WISE will provide a vast database of new astrometric and radiometric information on previously unknown asteroids.

Mather also anticipates surprises, "It's likely WISE will discover things we don't know anything about. WISE is much more sensitive than any previous infrared survey -- a tremendous advance. From experience with Hubble and COBE, I have faith that surprises will be found when you have equipment that's way better than anything else."

WISE is an Explorer-class mission, but it is still too early in the planning stages (extended Phase A) to determine Goddard's role completely. Dr. Edward Wright of the University of California, Los Angeles, will be the WISE Principal Investigator. NASA's Jet Propulsion Laboratory, Pasadena, Calif., will manage the project, and contractors will provide the spacecraft and instruments.

For more about WISE, refer to: http://www.astro.ucla.edu/~wright/WISE/

For more about John Mather, refer to: http://www.jwst.nasa.gov/Bios/ProgJMather.htm

For more about JWST, refer to: http://jwst.gsfc.nasa.gov/