Dark matter is estimated to make up about 27% of the universe, while visible matter makes up only about 5%.

There are three main lines of evidence for the existence of dark matter: the rotation curves of galaxies, the gravitational lensing of light, and the cosmic microwave background radiation.

The most popular theory about the nature of dark matter is that it is made up of weakly interacting massive particles (WIMPs). WIMPs are hypothetical particles that are thought to be very heavy and to interact with each other only through weak nuclear forces.

The main challenge in studying dark matter is that it is invisible to telescopes, does not interact with light, and is very difficult to detect.

Dark matter could have a number of consequences, including affecting the formation and evolution of galaxies, explaining the observed acceleration of the universe, and providing a new source of energy.

There are a number of ongoing experiments that are searching for dark matter, including the Large Hadron Collider (LHC), the LUX experiment, and the XENON experiment.

The hypothetical particle that is thought to make up dark matter is called a WIMP (Weakly Interacting Massive Particle).

The approximate mass of a WIMP is thought to be around 10^-22 kg.

The LUX experiment is searching for WIMPs in the Milky Way.

The CAST, IAXO, and ADMX experiments are all searching for axions.

The LSND, MiniBooNE, and ICARUS experiments are all searching for sterile neutrinos.

WIMPs are the most promising candidate for dark matter because they are well-motivated by particle physics theories and they can explain a wide range of observations.

The main challenge in detecting dark matter is that it is invisible to telescopes, does not interact with light, and is very difficult to distinguish from other particles.

Dark matter could have a number of consequences, including affecting the formation and evolution of galaxies, explaining the observed acceleration of the universe, and providing a new source of energy.

New experiments are being planned to search for dark matter and theories about dark matter are being developed.