Astronomers are plenty excited today over the news that an experiment aboard the International Space Station may have caught the first glimpse of dark matter. You know, the "mysterious substance that may hold the cosmos together," in the words of USA Today. Or the "mysterious dark matter that gives shape to the visible structures of the universe," says the New York Times. Or the "mysterious dark matter which makes up more than a quarter of the universe but has never been seen," says Reuters.
Even if it's a little slippery for those who aren't astrophysicists to grasp, one thing that is clear is that this is a big day for the ISS, writes Clara Moskowitz at Space.com. And that will hold true even if the stuff detected via a $2 billion cosmic ray detector (official name Alpha Magnetic Spectrometer) turns out to be something less scintillating than dark matter. "It's a very major step forward by at least an order of magnitude in sensitivity," a Brown University physicist tells the website. Adds theoretical physicist Robert Garisto: "I think it is fair to say that this is the most important physics result thus far to come from the International Space Station." (Read more dark matter stories.)