For 10 years, scientists had been observing one of the largest known stars in the universe, located in a galaxy 75 million lightyears away.
Then one day, it disappeared — and no one knows why. Read more.
Is this a neutron star or black hole?
This strange object is about 2.6 times the mass of the Sun and resulted from a collision between two unknown cosmic objects. Read more.
Scientists used to wonder whether these split-second bursts of radio waves bombarding Earth might be from aliens.
Now, they know it’s more likely from a massive object like a black hole or neutron star. Read more.
When neutrinos seemed to be traveling through Earth, scientists were left without answers. Some got excited about a potential parallel universe, but that’s more a science-fiction dream.
More likely, scientists discovered a new kind of particle. Read more.
Two of the most enduring space mysteries out there are dark matter and dark energy, which scientists evoke trying to explain the universe’s mass and accelerated expansion. Read more.