Dark matter and dark energy—the mystery forces believed to govern the universe—may not exist after all. In a newly developed model, astronomer André Maeder has found that neither of these concepts is needed for the universe to be expanding at an accelerating rate.
Here’s a bit of good news: There are fewer “killer rocks” that could wipe out life as we know it. NASA and other space agencies around the world have spent decades tracking near-Earth asteroids to determine whether any could slam into our planet. All the while, astronomers have wondered how many of these NEAs had gone undiscovered.