Question

Why are light-years more convenient than miles, kilometers, or astronomical units (AU) for measuring the distances to stars and galaxies? (Select all that apply.)
A. because in viewing a distant galaxy, the distance in light-years to the galaxy tells us how far back in time we are viewing the galaxy because light-years are the units astronomers have been using since the beginning of modern astronomy and are used only to be consistent with historical convention
B.because distances between objects in the universe are very large compared to the distances between objects on Earth and in our solar system,
C. measuring distances between objects in the universe in miles, kilometers, or astronomical units would require using very large numbers
D. because only light-years can provide an accurate measurement of how far light travels across the universe

Answer 1

Answer:

a,b,c

Explanation:

The light years is the length units that by now we use to measure the distances in universe. They are the biggest from the ones that were mention.

A light year is equivalent to 9.46 trillion km. An astronomic unit is equivalent to 150 million kilometers.

Also for practice is better to use light years than mention a distance in million or trillions of km from the Earth or another point in the universe.

Another use of the light years is that we an imagine the time (and the distance) that take to observe a universal body from its place to the Earth, like another star, planet, galaxy, etc.