A: Astronomers can calculate mass in several ways. The simplest is when the object is part of a binary system. Regardless of the objects in the binary — two stars, a star and a neutron star, a star ...

It's fun to think about how we know stuff. For instance, the sun has a mass of about 2 x 10 30 kilograms. That is such an enormous mass that it's difficult to comprehend. And if it's so difficult for ...

It’s true that you can’t simply place a planet or galaxy on a scale to measure how heavy it is. Luckily, astronomers have a few tricks up their sleeves. The first trick is understanding that gravity ...

Speed can make objects act as if they have more mass, but can you ever make an object appear to have less mass? It’s true that speeding an object up to considerable fractions of the speed of light ...

The terms weight and mass are often used incorrectly. Phrases like ‘a bag of sugar weighs 1 kg’ are not scientifically correct. This means that a 1 kg mass would be attracted to Earth by a force of 10 ...