This artistic rendering shows the distant view from Planet Nine back towards the sun. The planet is thought to be gaseous, similar to Uranus and Neptune. Hypothetical lightning lights up the night side. Credit: NASA/JPL-Caltech/Robert Hurt

Related channels: THE SOLAR SYSTEM, ASTEROIDS, COMETSKUIPER BELT, OORT CLOUD, THE SUN, MERCURY, VENUS, EARTH, THE MOON, MARS, JUPITER, SATURN, URANUS, NEPTUNE, DWARF PLANETS, MOONS