I don't think they are "important"; but they are convenient units of length - AU for distances within the Solar System (or other comparable distances); light-years (and parsecs) for larger distances.
1 AU = 0.0000158 light-years
The distance from the Sun to Sedna is approximately 86 astronomical units (AU). Since light travels at a speed of about 186,282 miles per second, it would take roughly 13.7 hours for light to travel from the Sun to Sedna. This is equivalent to around 822 minutes.
Distances within the solar system are usually reported in kilometers or AUs.1 AU = average distance of Earth from the Sun, about 150 million kilometers (149,597,871 km).Nearby . . . miles or kilometersOut past that . . . AU (Astronomical Units)Out past that . . . Light YearsOut past that . . . Parsecs
8.6 light years8.6 light years8.6 light years8.6 light years
It's exactly 7 light years away.One light year is the distance that light travels through space in one year.7 of those is a distance of something like 41,150,289,900,000 miles.
1 AU = 0.0000158 light-years
600 light-years is 37,944,646.2 AU
16 light years is 1,011,834.75 AU (Astronomical Units).
2.25 AU
35.2 AU = roughly 0.000557 light-year (rounded)
They really are not comparable. Light travels 186,000 miles per second, and one AU is about 8.3 light-MINUTES. You can probably do the math, from minutes to hours to days to years as well as I can. Or, you could google "1000 light years in AU" and get the answer
1 light year is approximately 63,241 AU. Therefore, 4.7 light years is about 297,116 AU.
Saturn is approximately 9.5 AU from the sun, which is about 0.00015 light years.
5.5 light years equates to 347,818.194 AU (Astronomical Units).
The average distance between Mercury and Venus is approximately 0.5 astronomical units (AU), where 1 AU is approximately 93 million miles. One light year is about 63,241 AU, so the distance between Mercury and Venus is about 0.0000079 light years.
(LY) Light Years and (AU) Astronomical Unit.
Light Years or AU (Astronomical units). It depends on what you are mesuring. For example the distance to the nearest star besides the sun is aproximitly 4.2 light years away vs. the earth is 1 AU away from the sun. (the au is the distance between the earth and the sun)