Hubble Space Telescope spots rogue planet with a little help from Einstein: 'It was a lucky break'

The Hubble Space Telescope detected an anomaly. But it was a scientist who figure it out; Einstein had correctly posited that a planet would create a sort of ripple in its wake. And that's what they saw that encouraged them to study the space further. 

A rogue planet! How very unusual. 

https://www.space.com/astronomy/exoplanets/hubble-space-telescope-spots-rogue-planet-with-a-little-help-from-einstein-it-was-a-lucky-break