Gamma-rays and Comet Dust
Image Credit &
Copyright:
Daniel López
(El Cielo de Canarias)
Gamma-rays
and dust from periodic Comet Swift-Tuttle plowed through
planet Earth's atmosphere on the night of August 11/12.
Impacting at about 60 kilometers per second the grains of
comet dust produced this year's remarkably
active Perseid meteor shower.
This composite wide-angle image of aligned shower meteors
covers a 4.5 hour period on
that Perseid night.
In it the flashing meteor streaks can be traced
back to the shower's origin on the sky.
Alongside the Milky Way in the constellation Perseus,
the radiant marks the direction along the perodic
comet's
orbit.
Traveling at the speed of light, cosmic gamma-rays impacting Earth's
atmosphere generated showers too, showers of high energy particles.
Just as the meteor streaks point back to their origin, the
even briefer flashes of light from the particles can be used
to reconstruct the direction of the
particle
shower, to point
back to the origin on the sky of the incoming gamma-ray.
Unlike the meteors, the incredibly fast particle shower flashes
can't be followed by eye.
But both
can be followed by the high speed cameras on the
multi-mirrored dishes in the foreground.
Of course, the dishes
are MAGIC
(Major Atmospheric Gamma Imaging Cherenkov) telescopes,
an Earth-based gamma-ray observatory on the Canary Island of La Palma.