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 ...

In a recent piece for my column The Universe, I wrote about the biggest black holes in the cosmos. Black holes are rather ...

Astronomers cannot directly weigh celestial objects like galaxies; indirect methods are necessary. Mass determination leverages the relationship between gravity and mass, utilizing orbital periods and ...

Astronomers use many methods to determine this number, including gravitational lensing, the universe’s expansion rate, and more.

How do we know the mass of a planet originally appeared on Quora - the knowledge sharing network where compelling questions are answered by people with unique insights. Answer by Geoffrey Widdison on ...

There are quite a few fundamental constants. These are things like the speed of light (c) the charge on an electron (e), and the Planck constant (h). These constants are determined with some type of ...

I/ATLAS interstellar object much larger than previously thought has been studied by scientists. New findings show it is ...

This is a good question, and also a good reminder to be careful with one’s language when writing about physics! Most of the time, if you’re reading an article, what we mean by mass and rest mass is ...

How do rogue planetary-mass objects -- celestial bodies with masses between stars and planets -- form? An international team of astronomers has used advanced simulations to show that these enigmatic ...