Using a new statistical technique to analyse publicly available data
from NASA's Fermi Space Telescope, an astrophysicist in Germany says he
may have spotted a tell-tale sign of exotic particles annihilating
within the Milky Way. If proved to be real, this "gamma-ray line" would,
he claims, be a "smoking-gun signature" of dark matter.
There is a wide body of indirect observational evidence that an
invisible substance accounts for some 80% of the matter in the universe.
Although physicists can measure the effects that this dark matter has
on the visible universe, they have very little understanding of what
this mysterious stuff actually is. As well as looking for direct
evidence of dark matter by detecting it – or even producing it – here on
Earth, researchers are also scouring the skies for signs of the
particles that dark matter might produce when self-annihilating. An
excess of high-energy positrons (anti-electrons) observed by the
Italian-led PAMELA spacecraft in 2008, and confirmed by Fermi last year,
might be such a signature. However, it is possible that these positrons
are produced by processes unrelated to dark matter. See:Gamma rays hint at dark matter
Also a Physics World see:
Has Fermi glimpsed dark matter?
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