After the initial success, Chang proposed launching a dark matter satellite-one with more advanced detectors and higher resolution-in space rather than in the atmosphere. In space there is stronger cosmic radiation and less interference.
"The indirect evidence can give us a glimpse into dark matter, just as we can infer the nature of a father by seeing his son," Chang said.
Besides the attempt to find indirect evidence, Chinese scientists are doing parallel experiments to find direct evidence.
In 2010, the Jinping Underground Laboratory-a dark matter laboratory beneath 2,400 meters of rock-was put into operation by two groups of experimenters: the international project PandaX led by Shanghai Jiao Tong University, and the CDEX project from Tsinghua University.
Using approaches different from those of astrophysicists, these groups try to observe dark matter directly instead of tracing it via the particles emitted during annihilation events.
"Imagine that you are driving your car in the pollution haze, and each time a pollutant particle hits into your car it makes a weak sound. What we are doing in the underground laboratory is trying to figure out these sounds," said Liu Jianglai, a professor at the Shanghai school and a member of the PandaX team.