Dark matter makes up the majority of mass in our universe. However, we cannot directly measure the stuff as it doesn't interact with electromagnetic radiation (i.e. it doesn't emit or reflect any light), but we can indirectly observe its presence. In the Hubble Space Telescope image above, the distribution of mostly dark matter has been calculated and mapped. Basically, the location and density of anything with mass has been plotted in a 3D representation of the cosmos.
A 2011 study suggests that mysterious, invisible dark matter could warm millions of starless planets in regions such as Abell 1689 (image below) and make them habitable.
The scientists concluded that on planets in dense "dark-matter" regions, it may be dark matter rather than light that creates the basic elements you need for organic life without a star"
Dark matter, the team believes, could keep the surfaces of such warm for trillions of years, outliving all regular stars and may ultimately prove to be the "dark" bastion of life in our universe.
"I imagine 10 trillion years in the future, when the universe has expanded beyond recognition and all the stars in our galaxy have long since burnt out, the only planets with any heat are these here, and I could imagine that any civilization that survived over this huge stretch of time would start moving to these dark-matter-fueled planets," Hooper said in an interview with space.com.
The Daily Galaxy via astrophysical journal