Assertion: spacecraft's distance | /r/HasProperty | expressed in light-years
Facets:
value: because of this
type: CAUSE
value: usually
type: TEMPORAL
Source sentences:
text: Because of this, distances between stars are usually expressed in light-years (defined as the distance that light travels in vacuum in one Julian year) or in parsecs (one parsec is 3.26 ly, the distance at which stellar parallax is exactly one arcsecond, hence the name).