Assertion: dark matter | /r/HasProperty | mysterious substance
Facets:
Source sentences:
text: Dark matter is a mysterious substance thought to compose perhaps about 27% of the makeup of the universe.
text: The reason that dark matter is so mysterious is that it pretty much never does anything, which makes it hard to spot.
text: Dark matter is the mysterious material that holds the Universe together, yet no one has seen it; or heard, smelled, tasted or touched it either.
text: Dark Matter are a mysterious group of Enemies interested in unlocking the secrets of Arktech.
text: Dark matter is one of the unsolved mysteries in physics and astrophysics.
text: Dark matter is the mysterious substance that makes up roughly a quarter of the Universe.