How do black holes like this form? The two black holes that spiraled together to produce the gravitational wave event GW190521 were not only the most massive black holes ever […]

Where do land and sky converge? On every horizon — but in this case the path on the ground leads to St Michael’s Mount (Cornish: Karrek Loos yn Koos), a […]

This is the mess that is left when a star explodes. The Crab Nebula, the result of a supernova seen in 1054 AD, is filled with mysterious filaments. The filaments […]

Illuminating planet Earth’s night, full moons can have many names. This year the last full moon of northern hemisphere summer was on September 2, known to some as the Full […]

Open star cluster NGC 7380 is still embedded in its natal cloud of interstellar gas and dust popularly known as the Wizard Nebula. Seen on the left, with foreground and […]

M31, the Andromeda Galaxy, is the closest large spiral galaxy to our Milky Way. Some 2.5 million light-years distant it shines in Earth’s night sky as a small, faint, elongated […]

How many moons do you see? Many people would say one, referring to the Earth’s Moon, prominent on the lower left. But take a closer look at the object on […]

Does Ceres have underground pockets of water? Ceres, the largest asteroid in the asteroid belt, was thought to be composed of rock and ice. At the same time, Ceres was […]

SS 433 is one of the most exotic star systems known. Its unremarkable name stems from its inclusion in a catalog of Milky Way stars which emit radiation characteristic of […]

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the […]