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 ...

Puny particles have given scientists a glimpse inside the Earth. For the first time, physicists have measured the planet’s mass using neutrinos, minuscule subatomic particles that can pass straight ...

If someone asked you to weigh the planet – assuming you haven't paid much attention during physics in high school – you might not know where to start. How do you weigh a thing you're standing on? That ...

Despite being stuck on this rock tumbling through space all the time, we don't really know exactly how heavy that rock is, or how its mass is distributed. Of course, researchers have some pretty good ...