There is an ongoing debate about whether a huge “super-Earth” lurks in the far reaches of our solar system – but we may actually have observed it almost 40 years ago
15 November 2021
Evidence for a massive planet in the outer solar system has been found, which may be the elusive Planet Nine that astronomers have long sought.
Planet Nine is a hypothesised world orbiting far beyond Neptune, in our solar system’s outer reaches. The gravitational clustering of some objects in the outer solar system suggests the presence of such a world, a super-Earth at least five times as massive as our planet, but no concrete evidence for it …