How does the earth revolve around the sun?

Question

Christopher Ales · Accepted Answer

The path of revolution of the center E of the Earth, about the center S of the Sun, is an ellipse. S is a focus of this ellipse. Distance SE is governed by #SE = (a(1-e^2))/(1+e cos(theta))#

#theta# is the inclination of SE to the initial line #theta=0#. Semi-major of the ellipse a = 149598262 km, nearly. The eccentricity of the ellipse e + 0.01671, nearly.

For one revolution, the period for #theta = 2pi# and the time-period is 365.265363 days, nearly.

At #theta=0#, SE is the minimum ( perihelion ) = #a(1-e)# = 147.1 Million km, nearly. This happens around Jan 3. At #theta=pi#, SE is the maximum (aphelion) = #a(1+e)# = 152.1 Million km, nearly. This happens around July 2. #theta > pi/2#, when SE = a. This is an end of the minor axis of the ellipse.

Crucially, S is almost 2.5 million kilometers (CS = ae) away from the ellipse's center, C.

Levi Acosta · Answer

undefined The Earth's orbit is elliptical, with the Sun at one of its foci; the Earth's orbit is roughly circular, but slightly elliptical, resulting in variations in the Earth's distance from the Sun throughout the year. The Earth revolves around the Sun due to the gravitational attraction between the two bodies.