Chandra's deep look at a rapidly rotating neutron star may provide new insight into the nature of some of the densest matter in the universe.
A new analysis of Kepler data shows that about 17 percent of stars have an Earth-sized planet in an orbit closer than Mercury.
Measuring tip-to-tip across its two outsized spiral arms, NGC 6872 spans more than 522,000 light-years, making it more than five times the size of our Milky Way galaxy.
Four of the potential new planets are less than twice the size of Earth and orbit in the "habitable zone," where liquid water might exist.