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NASA Renames Observatory for Fermi, Reveals Entire Gamma-Ray Sky
J.D. Harrington
Headquarters, Washington

David Harris
Stanford Linear Accelerator Center, Menlo Park, Calif.

Lynn Cominsky
Sonoma State University, Rohnert Park, Calif.

Release No. 08-214

Logo for Fermi Gamma ray Space Telescope Logo for the Fermi Gamma-ray Space Telescope. Credit: NASA/Sonoma State University/Aurore Simonnet
> Larger image
WASHINGTON -- NASA's newest observatory, the Gamma-ray Large Area Space Telescope, or GLAST, has begun its mission of exploring the universe in high-energy gamma rays. The spacecraft and its revolutionary instruments passed their orbital checkout with flying colors.

NASA announced today that GLAST has been renamed the Fermi Gamma-ray Space Telescope. The new name honors Prof. Enrico Fermi (1901 - 1954), a pioneer in high-energy physics.

"Enrico Fermi was the first person to suggest how cosmic particles could be accelerated to high speeds," said Paul Hertz, chief scientist for NASA's Science Mission Directorate at NASA Headquarters in Washington. "His theory provides the foundation for understanding the new phenomena his namesake telescope will discover."

Scientists expect Fermi will discover many new pulsars in our own galaxy, reveal powerful processes near supermassive black holes at the cores of thousands of active galaxies and enable a search for signs of new physical laws.

For two months following the spacecraft's June 11 launch, scientists tested and calibrated its two instruments, the Large Area Telescope (LAT) and the GLAST Burst Monitor (GBM).

The LAT team today unveiled an all-sky image showing the glowing gas of the Milky Way, blinking pulsars, and a flaring galaxy billions of light-years away. The map combines 95 hours of the instrument's "first light" observations. A similar image, produced by NASA's now-defunct Compton Gamma-ray Observatory, took years of observations to produce.

The image shows gas and dust in the plane of the Milky Way glowing in gamma rays due to collisions with accelerated nuclei called cosmic rays. The famous Crab Nebula and Vela pulsars also shine brightly at these wavelengths. These fast-spinning neutron stars, which form when massive stars die, were originally discovered by their radio emissions. The image's third pulsar, named Geminga and located in Gemini, is not a radio source. It was discovered by an earlier gamma-ray satellite. Fermi is expected to discover many more radio-quiet pulsars, providing key information about how these exotic objects work.

A fourth bright spot in the LAT image lies some 7.1 billion light-years away, far beyond our galaxy. This is 3C 454.3 in Pegasus, a type of active galaxy called a blazar. It's now undergoing a flaring episode that makes it especially bright.

The LAT scans the entire sky every three hours when operating in survey mode, which will occupy most of the telescope's observing time during the first year of operations. These fast snapshots will let scientists monitor rapidly changing sources.

The instrument detects photons with energies ranging from 20 million electron volts to over 300 billion electron volts. The high end of this range, which corresponds to energies more than 5 million times greater than dental X-rays, is little explored.

The spacecraft's secondary instrument, the GBM, spotted 31 gamma-ray bursts in its first month of operations. These high-energy blasts occur when massive stars die or when orbiting neutron stars spiral together and merge.

The GBM is sensitive to less energetic gamma rays than the LAT. Bursts seen by both instruments will provide an unprecedented look across a broad gamma-ray spectrum, enabling scientists to peer into the processes powering these events.

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

Biography of Enrico Fermi

Enrico Fermi (1901-1954) was an Italian physicist who immigrated to the United States. He was the first to suggest a viable mechanism for astrophysical particle acceleration. This work is the foundation for our understanding of many types of sources to be studied by NASA’s Fermi Gamma-ray Space Telescope, formerly known as GLAST.

Fermi is most noted for his work on the development of the first nuclear reactor and for his major contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics. He was awarded the Nobel Prize in Physics in 1938 for his work on induced radioactivity and is today regarded as one of the top scientists of the 20th century.

In addition to his direct connection to the science, Fermi holds special significance to the U.S. Department of Energy, the Italian Space Agency, and the Italian Particle Physics Agency.

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

Related links:

> Listen to the First Light telecon (MP3 file 7 MB)
> Enrico Fermi bio from
> Read this release in Italian from Agenzia Spaziale Italiana
> Read this release in German from the Max Planck Institute for Extraterrestrial Physics (pdf)