Astronomers have
further constrained the likely whereabouts
of Planet Nine: the planet that, if it exists, is more massive than the Earth and roams the
outer reaches of the
solar system.
Last year's historic close flyby
of Pluto by NASA's New Horizons spacecraft put the
outer Solar System firmly back in the spotlight, providing both scientists and the general public with ground - breaking and revolutionary discoveries about the
far - off little world in the
outer reaches of the Sun's planetary family.