Researchers have discovered an exoplanet that travels around its small, red star backward, much like a rubber duck spinning against the current in a whirlpool. The discovery could give insight about how exoplanets form around the most common types of stars in our galaxy.It's a mystery why the alien world, called GJ 3090 b, orbits its star backward (also called a retrograde orbit). Stars and planets usually form from the same rotating disk of gas and dust, called a protoplanetary disk. Newly formed celestial objects normally rotate in the same direction as the protoplanetary disk, because changing the rotational direction requires a lot of energy applied in the right way.Astronomers have disc...