Dark matter is the missing material making up 80 % of earth 's mass . Gamma rays from a dwarf galaxy are also a sign of dark matter . They were detected in clusters of ' Reticulum 2 ' billion light - years away . Scientists say this is the most convincing sign of dark matter yet .
Dark matter is the missing material making up 80 % of universe 's mass . Gamma rays from a dwarf galaxy are considered a sign of dark matter . They were spotted in direction of 'Reticulum 2 ' 98,000 light-years away . Scientists say this is the most convincing signal of dark matter yet .