NASA has awarded $1.4 million to six companies, to further their ideas about how to get vehicles farther into space cheaply ...

Most planet-forming disks have warps that can lead to planets on inclined orbits, which could explain where the tilt of Earth's orbit came from.

The time that planets take to orbit their suns have no specific relationship to each other. But sometimes, their orbits display striking patterns.

The type of orbit an exoplanet occupies could result in astronomers missing out on possible radio transmissions coming from the planet.

The result was surprising: HD 3167b’s orbit is nearly perpendicular to that of HD 3167c. This model shows the orbits of two planets around the star HD 3167.

It seems like everything orbits something in space. Moons orbit planets. Planets orbit stars. Stars orbit the centers of galaxies. But beyond that, things get a little harder to visualize. Do ...