Dark matter, the elusive, invisible stuff that astronomers say constitutes roughly 85% of the universe\u2019s mass, doesn\u2019t interact with light. Scientists only suspect it\u2019s there because of the way the things we can see interacts with it. But now, one team in China says it\u2019s found the most direct evidence for dark matter yet.<\/p>\n
According to a recently published<\/a> study in Physical Review Letters, astrophysicists with the Chinese Academy of Sciences found a \u201csharp\u201d gamma-ray signal among 15.5 years\u2019 worth of data from the Fermi Gamma-ray Space Telescope (FGST). The signal, the paper argues, is observable support for the leading theory of dark matter, which posits that dark matter is composed of weakly interacting massive particles (WIMPs). This gamma-ray signal is what you would expect to see when those particles collide and annihilate each other.<\/p>\n \u201cDiscovering a sharp gamma-ray line would be the ultimate \u2018smoking gun\u2019 evidence proving the existence of dark-matter particles and revealing their properties in particle physics,\u201d Yi-Zhong Fan, the study\u2019s first author, told New Scientist<\/a>.<\/p>\n Gamma rays are among the most powerful types of radiation in nature and a key area of interest in the search for dark matter, especially for scientists who support the WIMP theory. As per their name, WIMPs interact too weakly with the electromagnetic and nuclear forces to be observable via light or other particle interactions with normal matter.<\/p>\n On the other hand, WIMP-to-WIMP collisions should produce telltale gamma rays.<\/p>\n An intense gamma ray source with unknown origins is naturally going to leads some scientists to wonder if dark matter was responsible. At least, the latest study is far from being the first to do so. Last year, one team argued that the gamma glow at the Milky Way\u2019s center was dark matter<\/a>. Then one month later, another researcher claimed WIMPs were responsible for another odd gamma-ray signal<\/a>, also from FGST data.<\/p>\n