Set it went into operation, Fermi’s Large Area Telescope has detected 1873 gamma rays out in space, of which only two thirds have had their sources traced. Typically, gamma rays are huge bursts of energy generated by the collision between two stars or by black holes, however more than 600 discovered blasts still don’t have an explanation for their origin.
Several hypotheses have been launched around these untraceable super-energetic forms of light, the most popular possibility being that they’ve been triggered by some kind of dark matter event. Scientists know very little about dark matter, since it’s very hard to study due to the fact that it doesn’t emit any light, hence the “dark” adjective. What they do know is that it has a strong gravitational pull and that it makes up around 85% of the Universe, there rest being anything else we’re actually able to observe.
This a very interesting hypothesis, which might lead to some staggering discoveries. Dark matter can’t be observed using conventional means like a telescope or radio telescope, because it doesn’t shine, however inside a gamma ray blast, it might do. How would dark matter generate a gamma-ray blast?
“Some researchers believe that when two dark matter antiparticles bump into each other, they will annihilate, producing gamma rays. Concentrated clouds of dark matter could form a gamma ray source at specific wavelengths detectable by Fermi,” NASA explains.
“If we see a bump in the gamma-ray spectrum – a narrow spectral line at high energies corresponding to the energy of the annihilating particles – we could be the first to ‘apprehend’ dark matter,” Peter Michelson of Stanford University, the principal investigator for the Large Area Telescope said.
Watch NASA’s video “ScienceCasts: 600 Mysteries in the Night Sky” here: