The NASA Hubble Space Telescope image above shows the center of the giant galaxy cluster Abell 1689, containing about 1,000 galaxies and trillions of stars. Two billion light-years away, Abell 1689 is one of the most massive objects in the Universe. In this view from the Hubble Space Telescope's Advanced Camera for Surveys, the Abell cluster is seen to warp space as predicted by Einstein's theory of gravity -- bending light from individual galaxies which lie behind the cluster to produce multiple, curved images. The power of this enormous gravitational lens depends on its mass, but the visible matter, in the form of the cluster's yellowish galaxies, only accounts for about one percent of the mass needed to make the observed bluish arcing images of background galaxies.
Scientists have recently theorized that invisible dark matter could warm millions of starless planets in regions such as Abell 1689 and make them habitable.
Scientists think the invisible, as-yet-unidentified dark matter which we know exists because of the gravitational effects it has on galaxies, makes up about 85 percent of all matter in the universe.
Current prime candidates for what dark matter might be are massive particles that only rarely interact with normal matter. These particles could be their own antiparticles, meaning they annihilate each other when they meet, releasing energy. These invisible particles could get captured by a planet's gravity and unleash energy that could warm that world, according to physicist Dan Hooper and astrophysicist Jason Steffen at the Fermi National Accelerator Laboratory in a 2011 study.
Hooper and Steffen's propose that rocky "super-Earths" in regions with high densities of slow-moving dark matter could be warmed enough to keep liquid water on their surfaces, even in the absence of additional energy from starlight or other sources.The density of dark matter is expected to be hundreds to thousands of times greater in the innermost regions of the Milky Way and in the cores of dwarf spheroidal galaxies than it is in our solar system.
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, 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
Image credit: N. Benitez (JHU), T. Broadhurst (Hebrew Univ.), H. Ford (JHU), M. Clampin(STScI), G. Hartig (STScI), G. Illingworth (UCO/Lick), ACS Science Team, ESA, NASA