(one parsec is 3.26 ly, the distance at which stellar parallax is exactly one arcsecond, hence the name). Light in a vacuum travels around 300000 km per second, so 1 light-year is about {{convert 1e12|km|e12mi|abbr=off|sp=us}} or 1 ly AU. Hence, Proxima Centauri is approximately 4.243 light-years from Earth.

Another way of understanding the vastness of interstellar distances is by scaling. One of the closest stars to the Sun, Alpha Centauri A