Question

what's the meaning of radius of the orbit for the earth​

Answer 1

Lunar distance (astronomy) ... It is the average distance from the center of Earth to the center of the Moon. More technically, it is the mean semi-major axis of the geocentric lunar orbit.

Unit of: distance

Metric system: 384402 km

English units: 238856 mi

Unit system: astronomy

Answer 2

Every planet rotate around the Sun, or the central Star of their Solar system.

Now, these planets rotate along a fixed Orbit, known a s The Orbit of the planet.

The radius of this Orbit is known as the radius of the orbit for that planet.

The planet rotate around the Sun (fur example), than the radius is taken from the centre of the rotation orbit, i.e., the Sun till the boundary of the Orbit.

Generally, these orbits are elliptical in shape, Shape of Ellipse, whose radius is not fixed. And so a average radius is taken.

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