[Music throughout](Announcer): Liftoff of the Delta rocket carrying a gamma-ray telescope
searching for unseen....[fades out] (Narrator): I'm Julie Mcenery, Fermi project
scientist. Since its launch in 2008, the Fermi Gamma-ray
Space Telescope has revolutionized our understanding of the cosmos.
Fermi has mapped the entire sky in gamma rays, the highest-energy form of light,
and detected thousands of sources so far.
In celebration of its 10th anniversary in space, here are five of its
transformative discoveries. In 2017, Fermi saw
a gamma-ray burst coming from the constellation Hydra. The burst
was tied to ripples in space-time detected by the Laser Interferometer
Gravitational Wave Observatory, operated by the National Science Foundation.
This was the first time light and gravitational waves were detected from the same source.
Scientists believe the event formed when two neutron stars merged. The merger
created the gravitational signal and a jet of particles traveling at nearly the speed
of light that gave off gamma rays. In 2009,
Fermi used a short-duration gamma-ray burst to confirm that all light
travels at the same speed, no matter its energy. This proved Einstein's theory
that space-time is smooth and continuous.
Early in Fermi's mission, scientists noted odd structures emerging from
above and below the Milky Way. These bubbles, spanning
50,000 light-years, were produced by our galaxy's supermassive black hole and are
only a few million years old. In 2013,
Fermi studied the remains of two supernovas to learn more about cosmic rays,
particles traveling at nearly the speed of light. It was hard to find the source
of cosmic rays because they veer off course as they travel and encounter magnetic fields.
Fermi showed that gamma rays from these supernova remnants
came from cosmic rays that were accelerated by the explosions' blast waves.
Fermi has seen 5,000 terrestrial gamma-ray flashes
in the last 10 years. These flashes are associated with lightning
and thunderstorms in Earth's atmosphere.
From Earth, to the farthest reaches of the cosmos, Fermi's first ten years
have fundamentally altered how we look at the universe. Who knows what mysteries
remain to be solved?
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