Earth’s orbit around the Sun is not circular, but an ellipse. The perimeter of Earth’s orbit is roughly 584 million miles (940 million km).

“Circumbinary orbits that are polar or highly inclined to the Earth-Moon orbit are subject to two competing effects: nodal precession about the Earth-Moon eccentricity vector and Kozai-Lidov ...

Pluto, for example, has a highly elongated orbit compared to the planets in our solar system and has an orbital eccentricity of 0.25. Earth has an orbital eccentricity of just 0.02.

Astronomers may have solved the mystery of how hot Jupiter exoplanets are born, finding a gas giant with a weird orbit in the process of transforming into just such a world.

Astronomers have spotted a bizarre exoplanet with the most oblong, hairpin-style orbit ever discovered, and it may be on the path to becoming a “hot Jupiter.” ...

How much the Earth’s orbit deviates from a perfect circle is measured by its eccentricity. The higher the eccentricity, the more elliptical the orbit. Terry Virts/Johnson Space Center, via NASA ...

The findings highlight the roles of precession, obliquity, and eccentricity – factors influencing the tilt and movement of Earth's axis, and the shape of Earth's orbit around the Sun – in ...

“Circumbinary orbits that are polar or highly inclined to the Earth-Moon orbit are subject to two competing effects: nodal precession about the Earth-Moon eccentricity vector and Kozai-Lidov ...

Some orbits are ever so slightly elliptical (like a somewhat squashed circle, or, in astronomical terms, an orbit with low eccentricity), whilst some appear rather flattened (highly eccentric orbits).

Talk about star power! Stellar Encounter A passing star which blew past our solar system nearly 3 million years ago could have altered the Earth's orbit, researchers found.

Right now, the Moon orbits Earth from a respectable distance of about 239,000 miles (384,600 kilometers). But that's because ...