Which term is used to describe the distance between Earth and the Sun?

Which term is used to describe the distance between Earth and the Sun?

• A. Astronomical unit
• B. Light-year
• C. Parsec
• D. Meter

Answer: (A)

The distance from Earth to the Sun is described using an astronomical unit. An astronomical unit is the average distance between Earth and the Sun, about 93 million miles or 150 million kilometers. It’s a practical scale for talking about distances inside the solar system, since using meters or miles would be unwieldy for these vast gaps. It’s not a light-year or a parsec, which are used for much larger, interstellar distances (a light-year is how far light travels in a year, and a parsec is about 3.26 light-years). A meter is far too small to express solar-system distances, even though it’s the basic SI unit. In modern terms, one astronomical unit is defined exactly as 149,597,870,700 meters, reflecting the average Earth–Sun distance.

The distance from Earth to the Sun is described using an astronomical unit. An astronomical unit is the average distance between Earth and the Sun, about 93 million miles or 150 million kilometers. It’s a practical scale for talking about distances inside the solar system, since using meters or miles would be unwieldy for these vast gaps. It’s not a light-year or a parsec, which are used for much larger, interstellar distances (a light-year is how far light travels in a year, and a parsec is about 3.26 light-years). A meter is far too small to express solar-system distances, even though it’s the basic SI unit. In modern terms, one astronomical unit is defined exactly as 149,597,870,700 meters, reflecting the average Earth–Sun distance.