Ultrashort Flashes of Light – Separated Only by Quadrillionths of a Second – Combined Precisely and Quickly
Astronomers might have found the first exoplanet outside of our Milky Way. Revealed by X-rays, the bizarre world is about as big as Saturn, has lived through a nearby supernova, currently orbits a black hole or neutron star, and is destined to experience a second nearby supernova in the future.
Earth's spin has slowed. But we still may need a negative leap second.