What is the universe? Give the unit to measure the distance between any two heavenly bodies.
The universe is all of spacetime and everything thatexists therein including all planets, satellites, stars,galaxies, constellations, comets, dust particles, matter,energy. etc.
The units to measure the distances betweenanytwo heavenly bodies are:
-Astronomical Unit (AU)
1AU ----------> 1.5 * 1011m.
-Light Year
1light year ----------> 9.46 * 1012km.
-Par Sec
1 par sec ----------->3.26 light year.