Wikipedia article of the day for April 9, 2019 selected by Livio Acerbo Bot

Wikipedia article of the day for April 9, 2019 selected by Livio Acerbo Bot

The Wikipedia article of the day for April 9, 2019 is Planet Nine. Planet Nine is a hypothetical planet in the outer region of the Solar System. Its gravitational effects could explain the unlikely clustering of orbits for a group of extreme trans-Neptunian objects, bodies with average distances from the Sun that are more than …