Astronomers using the Keck II Telescope on Mauna Kea have found the most distant dwarf galaxy yet observed.

The discovery appears to confirm current theories that most of the mass in the cosmos is made up of mysterious "dark matter" that does not absorb or emit light.

The find, described in a notice published online Wednesday in the journal Nature, could help astronomers find similar objects and confirm or reject theories about the structure of the universe.

The dwarf galaxy is orbiting a larger companion 10 billion light years away, according to the lead author, Simona Vegetti, a postdoctoral researcher at the Massachusetts Institute of Technology, and astron-omers in California and the Netherlands.

Astronomers have detected about 30 satellite galaxies around our own, the Milky Way, and nearby, but never halfway across the universe.

Making the discovery possible were the Keck’s adaptive optics, which correct for the distortion of the atmosphere, and a phenomenon known as gravitational lensing. That occurs when light from an object is bent by the gravity of a closer object from Earth’s perspective.

In this instance, the light from one galaxy was bent by the gravity of another into a circle called an Einstein ring.

By analyzing the distortions in the ring, the researchers were able to determine there was a satellite around the "lens" galaxy. The technique now can be used to find other galactic satellites, which should be abundant according to current thinking.

"Now we have one dark satellite, but suppose that we don’t find enough of them?" Vegetti said in a statement Wednesday. "Then we will have to change the properties of dark matter. Or we might find as many satellites as we see in the simulations, and that will tell us that dark matter has the properties we think it has."

The dwarf galaxy has about the same mass as the Sagittarius 12 galaxy, a satellite of the Milky Way, the scientists calculated.