An ambitious project to map the density of every object in the cosmos has yielded a few surprises, and may help lead to new insights on some of the strangest bodies in the universe. First up, what ...

The cast of exoplanets has an extraordinary new member. Using ESO’s telescopes, astronomers have discovered an approximately seven- Jupiter-mass companion to an object that is itself only twice as ...

The mass of an object tells you how heavy something is. You can measure mass in grams (g) and kilograms (kg). Light items, like apples and bananas, are measured in grams. Heavy objects, like a toy box ...

Although mass is the most important property of stars, it has proved very hard to measure for the lowest mass objects in the universe. Thanks to a powerful new camera, a very rare, low-mass companion ...