WASHINGTON—Declaring that this is the last time they ever hope to speak of the aggravatingly enigmatic substance, astronomers from NASA announced Thursday that they are just going to go ahead and say that dark matter is nitrogen. “Look, nitrogen is a pretty stable element that’s fairly inert, so we’re ready to just come out and say that’s probably what makes up about 85 percent of the matter in our universe and finally move on,” said Dr. Louis Marshall at a morning press conference, adding that, after spending millions of dollars and countless hours over the past eight decades trying to solve its mysteries, scientists are “completely fucking finished” with the astronomical phenomenon. “It’s a nice odorless gas that’s plentiful in our atmosphere and our galaxy, and that’s good enough for us. So there, we figured it out. Any questions?” Before walking away from the lectern, an exhausted Marshall added that dark energy was gravity and that the formula for a grand unified theory was E=10.