NASA | What is Fermi?

Описание: The Fermi Gamma-ray Space Telescope is a NASA observatory designed to reveal the high-energy universe in never-before-seen detail. With Fermi, astronomers have a unique tool to explore high-energy processes associated with solar flares, spinning neutron stars, outbursts from black holes, exploding stars, supernova remnants and energetic particles to gain insight into how the universe works.

Fermi detects gamma rays, the most powerful form of light. How powerful? The energy of visible light falls between 2 and 3 electron volts, but the gamma rays detected by Fermi have energies several thousand to billions of times greater.

Fermi carries two instruments. Its Large Area Telescope (LAT) is vastly more capable than instruments flown previously, with higher angular resolution, wider field of view, greater energy resolution and range, and more precise time resolution for each gamma ray detected. The LAT tracks gamma rays with energies from 20 million electron volts (MeV) to more than 300 billion electron volts (GeV).

Fermi makes one orbit around Earth every 96 minutes and points the LAT upward at all times so our home planet never blocks its view of the cosmos. Scientists deliberately nod the LAT in a repeating pattern from one orbit to the next. It first looks north on one orbit, south on the next, and then north again, which allows the LAT to cover the entire sky in just two orbits. (For a LAT's-eye view of these motions, see this    • NASA | Fermi Traces a Celestial Spirograph  ).

Every few weeks, the LAT deviates from its normal pattern to concentrate on particularly interesting targets, such as eruptions on the sun, brief but brilliant gamma-ray bursts associated with the birth of stellar-mass black holes, and outbursts from supermassive black holes in distant galaxies.

Fermi's secondary instrument, the Gamma-ray Burst Monitor (GBM) has a much larger field of view, covering the entire sky not blocked by Earth. The GBM provides spectral coverage from the lower limit of the LAT down to 8,000 electron volts. The GBM is now the premier detector of gamma-ray bursts and has provided new insight into terrestrial gamma-ray flashes, high-energy bursts produced above thunderstorms.

With the LAT and GBM, Fermi is a flexible observatory for investigating the great range of astrophysical phenomena best studied in high-energy gamma rays. Since its launch on June 11, 2008, Fermi has made many discoveries. Some of these findings include:

Testing the fabric of time and space:    • NASA | Einstein's Cosmic Speed Limit  

Gigantic gamma-ray emitting bubbles in the Milky Way:    • NASA | Fermi discovers giant gamma-ray bub...  

Antimatter from lightning on Earth:    • NASA | Terrestrial Gamma-ray Flashes Creat...  

Huge flares in the Crab Nebula:    • NASA | Fermi Spots 'Superflares' in the Cr...  

A surprisingly young millisecond pulsar:    • NASA | Fermi Finds a Youthful Pulsar Among...  

New insights into dark matter:    • NASA | Fermi Provides New Insights on Dark...  

Gamma rays from solar flares:    • NASA | Fermi Detects Gamma Rays from a Sol...  

Light from the early universe:    • NASA | Fermi Explores the Early Universe  

Proving supernova remnants produce cosmic rays:    • NASA | Fermi Proves Supernova Remnants Pro...  

For more information about Fermi: http://www.nasa.gov/mission_pages/GLA...

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