4 ms·I bet you’d use lightyears over petametres or exametres though.by clickety_clack 2mo agoI bet you’d use lightyears over petametres or exametres though.Alpha3031 2mo agoIt's more typical to use parsecs in practice for astronomy.fsckboy 2mo agoyeah, and imagine living without decameters and hectometers, unthinkable!