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Correct!
Dark matter's gravity creates the sponge-like structure of the universe. Some areas are dense with galaxy clusters, while others are cosmic voids—big, empty bubbles, hundreds of millions of light years wide.
Definition: an invisible substance that makes up 80% of the total mass in the universe
Detection: only by its gravitational influence on normal matter
Influence: its gravity holds together galaxies and galaxy clusters
Proposed: in 1930s by Fritz Zwicky
Confirmed: in 1978 by Vera Rubin. To explain the orbits of stars in spiral galaxies, she estimated that most matter in galaxies is invisible.
The gravity generated by dark matter is responsible for the grand structure of the universe. This structure is like the inside of a:
Today, scientists are trying to detect dark matter particles directly. These ultra-sensitive "detectors" are placed:
deep beneath Earth's surface
on the International Space Station
both of these
Correct!
In North America and Europe, detectors are buried deep underground, shielded from radiation from space. One detector is mounted on the International Space Station, where it looks for signs of dark-matter particles far from Earth.
Scientists can detect regions with lots of dark matter because they are very dark.
Fact
OR
Fiction
?
Fiction
Dark matter doesn't interact with light in any way—it doesn't give off light, but it doesn't absorb light either. Scientists can detect dark matter only by its effect on galaxies.
Like normal matter, dark matter is made of atoms.
Fact
OR
Fiction
?
Fiction
Normal matter is made of protons, neutrons, and electrons. Scientists still haven't figured out what dark matter is made of but they know it's not atoms, which are detectable by light.
While the universe expands, galaxy clusters stay bound together: they don't expand.
Fact
OR
Fiction
?
Fact
The cosmic space of universe is expanding, carrying clusters of galaxies with it. But galaxy clusters, and the galaxy they hold, stay together, bound by the gravity of dark matter.