Before Pluto was discovered, the world’s astronomers were captivated by the possibility of finding another massive planet beyond the orbit of Neptune. In 1930, Pluto was discovered lurking in what was considered to be the edge of the Solar System. However, it quickly became apparent that Pluto was tiny; it wasn’t the Planet X we were looking for. For the last 80 years, astronomers have been looking for a large planet that might go to some way of explaining interplanetary features such as the “Kuiper Cliff”, but Planet X has not been found. Unfortunately, the word “Planet X” has now become synonymous with conspiracy theories and doomsday, almost as notorious as the word “Nemesis”.
Nemesis is another unanswered question hanging over Solar System evolution: does the Sun have a binary twin? Is there a second, dim, hidden “sun” stalking it’s brighter counterpart from over a light year away? Some scientists have come forward to suggest that the existence of a hypothetical second sun — embodied as a brown dwarf or red dwarf — could explain some cyclical effects here on Earth (i.e. mass extinctions occurring with a strange regularity). Naturally, the discussion about Nemesis (like the discussion about the possibility of a massive Planet X) is purely academic, and only based on indirect observations and anecdotal evidence. Just because they might exist, doesn’t mean they do.
In a publication recently published to the arXiv database, one Italian researcher has dusted off this topic and asked a very basic question: Can we constrain the possible locations of Nemesis and/or Planet X if they did exist? His results are fascinating…