An important upcoming experiment is the European Space Agency mission, Euclid. Due to be launched in 2022, it will try to measure the dark sector in multiple ways, including mapping the distribution of galaxies in the Universe, and measuring gravitational lensing distortions of galaxy images.
Image from the Euclid Consortium website, HERE if you’re interested to learn more.
This was the headline in the New York Times in 1919, when they reported on one of the classic tests of Einstein’s gravity. Arthur Eddington had led a team to measure how much the trajectory of light is affected by passing through the Sun’s gravitational field on the way to Earth. The observations were in agreement with Einstein’s theory, contributing to the acceptance of Einstein’s theory and his growing fame.
The dark matter in the standard cosmological picture is referred to as “cold dark matter”. The “cold” part signifies that, in particle terms, the dark matter particles are quite heavy, so they move relatively slowly (much less than the speed of light).
Much lighter particles (such as neutrinos) tend to move much faster, so are called “hot” dark matter.
Unlike for Goldilocks, “Cold” dark matter seems to fit just right according to our data.
Dark Matters 