Is the orbit of the Earth rounder?

Question

Has the orbit of the Earth around the sun gotten measurably rounder? Aren't we just a little closer to it now at least a couple times a year? Aren't we receiving a little more radiation (heat) because of the orbital change?

Answer 1

It's true that Earth's orbit is a bit rounder now, that 500 years ago: about 1.2% rounder (less eccentricity). But the semi-major axis has not change enough for anyone to notice. It's the semi-minor axis that has changed. So the Earth has gotten farther away from the Sun, for most of it's orbit.

Perhaps you would be interested in the Earth's insolation (Sunlight) for the past and future million years -- see the second source.

Answer 2

The orbit of the earth is not really changing over time, at least in a measurable way at our scale.
That said, earth's orbit is elliptic, and the earth is closer to the sun in mid January and farther in mid July, and yes, that does change the solar constant a wee bit.

Answer 3

As someone observed, the verse in Isaiah says the Earth is a circle, however, via the literal definition, a circle is a flat, 2-dimensional merchandise, as adversarial to a sphere, that's three-dimensional (and as Muldah observed, it isn't a perfect sphere). notwithstanding that's a controversy of semantics and difficulty to interpretation. The Catholic Church usually admits they were incorrect on certain themes, however that's often a lengthy time period or centuries after the actual actuality.

Answer 4

our orbit is an elipse.... seasons are affected by the tilt of the planet

Answer 5

Good question, never thought about it.