Astronomers using NASA’s Hubble Space Telescope have measured the rotation rate of an extreme exoplanet by observing the varied brightness in its atmosphere. This is the first measurement of the ...

A planet's north pole is defined by its position relative to the solar system's invariable plane. The invariable plane is a fixed reference point perpendicular to the solar system's rotation. A planet ...

General relativity helps explain the lack of planets around tight binary stars by driving orbital resonances that eject or destroy close-in worlds. This process naturally creates a “desert” of ...

Venus looks like Earth’s twin at first glance, yet its rotation behaves like a cosmic prank. The planet spins backward, crawls through a day that outlasts its year, and even changes its spin rate in ...