Problem: Surveying Astronomy: The Earth's Orbit and the Ecliptic

The orbit of the earth around the sun follows a path that quite closely resembles the shape of what geometric figure defined in Kepler’s laws of planetary motion?


(A)    A cycloid

(B)    A hyperbolic paraboloid

(C)    A cardioid

(D)    An ellipse


This is problem 28(4-15) from the new second edition of <em>1001 Solved Surveying Problems</em> by Jan Van Sickle. Reprinted with permission from <em>1001 Solved Surveying Problems</em> by Jan Van Sickle (1997, 728 pp., Professional Publications Inc.). For details on this and other FLS exam-prep books, call 800/426-1178 or visit


Answer: D


The first of Kepler’s laws states that every planet orbits the sun in an ellipse, with the sun itself at one focus of that ellipse. Observation has since proven this assertion fundamentally correct. The path of the earth around the sun, though nearly a circle, is elliptical.