September 4th, 2016
(written by lawrence krubner, however indented passages are often quotes). You can contact lawrence at: firstname.lastname@example.org
But now scientists have found something entirely new: a galaxy with the same mass as the Milky Way but with only 1 percent of our galaxy’s star power. About 99.99 percent of this other galaxy is made up of dark matter, and scientists believe it may be one of many.
The galaxy Dragonfly 44, described in a study published Thursday in the Astrophysical Journal Letters, is 300 million light years away. If scientists can track down a similar galaxy closer to home, however, they may be able to use it to make the first direct detection of dark matter.
[Dark matter is really dark, but not totally dark: Scientists are dialing in the darkness]
The researchers who found Dragonfly 44 weren’t looking for a dark galaxy. Another surprise: They found it using a telescope built of camera parts. The Dragonfly Telephoto Array was built by a group of astronomers at Yale University and the University of Toronto who realized that telephoto lenses — so often used for nature photography and sporting events — were well-suited for spotting the kind of large, dim objects that pose problems for typical telescopes.
“We planned to study the outskirts of galaxies to see what exists around them, but by accident we saw all these little smudges,” study author Pieter van Dokkum of Yale told The Post. At first, van Dokkum and his colleagues thought they were seeing image defects. But when they looked more closely at their data, they realized they’d found an entirely new class of object.
Let’s pause here to remind ourselves that scientists have no idea what dark matter is. Dark matter is the name given to a mysterious form of matter that we know must be there. Without something adding to the mass of the universe, things would tear apart. The laws of physics require some unknown, unseen kind of something to hold the universe together (while dark energy pushes it farther and farther apart). All we really know about dark matter is that it barely interacts with anything, including its own ilk.