If you guessed the astronomical unit, you are correct. The au — the rough distance between the Earth and the Sun — was previously determined by a confusing calculation (“the radius of an unperturbed ...

Scientists still define astronomical time in years, with some recent refinements. By C. Claiborne Ray Q. Do scientists actually speak of the age of the universe in years, or do they use some ...

One of the stalwart units of astronomy just got a makeover. The International Astronomical Union, the authority on astronomical constants, has voted unanimously to redefine the astronomical unit, the ...

Stephen has degrees in science (Physics major) and arts (English Literature and the History and Philosophy of Science), as well as a Graduate Diploma in Science Communication. Stephen has degrees in ...

A proposed five-satellite Cosmic Positioning System could measure cosmic distances directly and help address discrepancies in the Hubble constant through solar system–scale triangulation.