Why is earths distance away from the sun reported as an average distance?

Answer 1

No orbit is a perfect circle. Orbital paths are elliptical. So the distance from the sun to the Earth fluctuates during the course of a year from a minimum of 147.1 million kilometers (91 million miles) to a maximum of 152.1 million kilometers (94.5 million miles).

Answer 2

The light year is too large a unit to use within the solar system. It would result in inconveniently small numbers.

Probably the largest single quantity to talk about in the solar system is the distance across Pluto's orbit ...
like double Pluto's average distance from the sun. That distance is roughly 7.13 billion miles.

That's about 10.6 light-hours, or 0.001214 light-year.

Using the light-year to describe distances in the solar system is like using the inch or foot to describe
grains of salt. Sure, you can do it, but the numbers you get are really awkward.

Answer 3

For the same reason you probably don't report the length of your trip to your job in millimeters or inches. The numbers would just simply be too big and unwieldy. For example, the nearest star system to the sun is the Alpha Centauri triplet. It's distance is rounded to 9,460,890,000,000 kilometers (5,878,700,000,000 miles). Again ... out of several billion observable stars, we're talking about the nearest one. To put it another way ... kilometers and miles may be 'standard' for everyday life here on the little stone where we live, but they're completely inadequate to handle the dimensions we encounter once we board our imagination and leave the earth. New 'standards' were developed that are able to handle the job.

Answer 4

The Earth, like any other object in orbit, goes around the Sun in an elipse. Sometimes Earth is nearer to the Sun, at other times it is farther away.

Answer 5

The Earth's orbit around the sun isn't a perfect circle, it's more of an ellipse due to other gravitational forces in our solar system.