R🜨

Alternative forms

 * R⊕ [a common typographic substitution, as mathematical $⟨⊕⟩$ was supported by Unicode a decade before astronomical $⟨🜨⟩$]
 * The R is not always italic.

Etymology

 * R (radius) and subindex 🜨 (planet Earth).

Symbol

 * 1)  Earth radius: a unit of distance, equal to the radius of the Earth, or 6370 km.
 * the transition radius of 2.6 R🜨 between water worlds and planets with gaseous envelopes
 * 1)  The radius of the Earth specifically.

Usage notes

 * R🜨 may be distinguished from r🜨, the latter not a unit of measurement but meaning radial distance from the Earth (geocentric distance). Unlike R🜨, r🜨 is used relative to our planet specifically.

Synonyms

 * R♁ (R♁ is apparently uncommon as a comparative unit of measurement)
 * (English) RE