The rim of Burckhardt is generally circular but somewhat irregular in form.
Mandatory signs are generally circular with a white border and symbol on a blue background.
A star passing too close could knock a planet out of its generally circular orbit.
Carmichael is generally circular, with a small floor at the middle of the sloping interior walls.
The rim is generally circular, with some terracing of the inner wall.
The rim of this crater is generally circular, although the western side is straight.
The rim of this crater is generally circular, but with some irregularities.
The crater rim is low and generally circular in form.
Although generally circular, the crater outline has a hexagonal form.
The rim of the crater is slightly distorted, although generally circular.