(Phys.org)—Members of the International Astronomical Union have voted to approve a change to the definition of the famous "astronomical unit" aka, AU, from one based on variable data, to a definite ...

The sun still shines as bright, but according to the International Astronomical Union (IAU), its precise distance from us has just changed. At a recent meeting of the IAU in Beijing, China, members ...

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 ...

Click anywhere on this site, and you’ll likely run into a measurement in terms of light-years, solar masses, astronomical units, or arcminutes. These units are unique to astronomy, and all can be ...