After a decades-long search, astronomers may finally have found the first sign of dark matter. That's the invisible substance that scientists believe makes up the bulk of our universe, since visible matter accounts for only about 20 percent of our universe's mass.
While scientists can observe dark matter indirectly by looking at its gravitational effects on visible matter, they have struggled to come up with tangible evidence that proves the stuff exists--until now.
This week, a team of researchers from France and the Netherlands announced that they may have detected the signal of decaying dark matter particles.
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