J. D. Harrington
Headquarters, Washington
202-358-5241
j.d.harrington@nasa.gov

Lynn Chandler
Goddard Space Flight Center, Greenbelt, Md.
301-286-2806
lynn.chandler-1@nasa.gov



RELEASE 13-259


NASA's Fermi Celebrates Five Years in Space, Enters Extended Mission
*
During its five-year primary mission, NASA's Fermi Gamma-ray Space Telescope
has given astronomers an increasingly detailed portrait of the universe's
most extraordinary phenomena, from giant black holes in the hearts of distant
galaxies to thunderstorms on Earth.

But its job is not done yet. On Aug. 11, Fermi entered an extended phase of
its mission -- a deeper study of the high-energy cosmos. This is a
significant step toward the science team's planned goal of a decade of
observations, ending in 2018.

"As Fermi opens its second act, both the spacecraft and its instruments
remain in top-notch condition and the mission is delivering outstanding
science," said Paul Hertz, director of NASA's astrophysics division in
Washington.

Fermi has revolutionized our view of the universe in gamma rays, the most
energetic form of light. The observatory's findings include new insights into
many high-energy processes, from rapidly rotating neutron stars, also known
as pulsars, within our own galaxy, to jets powered by supermassive black
holes in far-away young galaxies.

The Large Area Telescope (LAT), the mission's main instrument, scans the
entire sky every three hours. The state-of-the-art detector has sharper
vision, a wider field of view, and covers a broader energy range than any
similar instrument previously flown.

"As the LAT builds up an increasingly detailed picture of the gamma-ray sky,
it simultaneously reveals how dynamic the universe is at these energies,"
said Peter Michelson, the instrument's principal investigator and a professor
of physics at Stanford University in California.

Fermi's secondary instrument, the Gamma-ray Burst Monitor (GBM), sees all of
the sky at any instant, except the portion blocked by Earth. This all-sky
coverage lets Fermi detect more gamma-ray bursts, and over a broader energy
range, than any other mission. These explosions, the most powerful in the
universe, are thought to accompany the birth of new stellar-mass black holes.

"More than 1,200 gamma-ray bursts, plus 500 flares from our sun and a few
hundred flares from highly magnetized neutron stars in our galaxy have been
seen by the GBM," said principal investigator Bill Paciesas, a senior
scientist at the Universities Space Research Association's Science and
Technology Institute in Huntsville, Ala.

The instrument also has detected nearly 800 gamma-ray flashes from
thunderstorms. These fleeting outbursts last only a few thousandths of a
second, but their emission ranks among the highest-energy light naturally
occurring on Earth.

One of Fermi's most striking results so far was the discovery of giant
bubbles extending more than 25,000 light-years above and below the plane of
our galaxy. Scientists think these structures may have formed as a result of
past outbursts from the black hole -- with a mass of 4 million suns --
residing in the heart of our galaxy.

To build on the mission's success, the team is considering a new observing
strategy that would task the LAT to make deeper exposures of the central
region of the Milky Way, a realm packed with pulsars and other high-energy
sources. This area also is expected to be one of the best places to search
for gamma-ray signals from dark matter, an elusive substance that neither
emits nor absorbs visible light. According to some theories, dark matter
consists of exotic particles that produce a flash of gamma rays when they
interact.

"Over the next few years, major new astronomical facilities exploring other
wavelengths will complement Fermi and give us our best look yet into the most
powerful events in the universe," said Julie McEnery, the mission's project
scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle
physics partnership. Goddard manages the mission. The telescope was developed
in collaboration with the U.S. Department of Energy's Office of Science, with
contributions from academic institutions and partners in the United States,
France, Germany, Italy, Japan, and Sweden.

For images and video related to this release, visit:

*http://go.nasa.gov/1f2vYAm

For more information about Fermi, visit:

*http://www.nasa.gov/fermi