For an Earth-orbiting gamma-ray telescope,
Earth is actually the brightest source of
gamma-rays, the most energetic form of light.
Gamma-rays from Earth
are produced when high energy particles,
from space, crash into the atmosphere.
While that interaction blocks harmful radiation from
reaching the surface, those gamma-rays dominate
in this remarkable Earth and sky view
from the orbiting
Gamma-ray Space Telescope's Large Area Telescope.
The image was constructed using only observations
made when the center of our Milky Way galaxy was near the zenith,
directly above the
The zenith is mapped to the center of the field.
The Earth and points near the nadir, directly below the satellite,
are mapped to the edges of the field resulting
in an Earth and all-sky projection
from Fermi's orbital perspective.
The color scheme shows low intensities of gamma-rays
as blue and high intensities as yellowish hues on a
Our fair planet's
brighter gamma-ray glow floods the edges of field,
the high intensity yellow ring tracing Earth's limb.
in the sky along the relatively faint Milky Way
stretch diagonally across the middle.
Launched June 11, 2008 to
this week Fermi celebrated its 2,000th day in low Earth orbit.
Large Area Telescope Collaboration,