New Examination of Trans-Neptunian Objects Suggests Two Planets Lurk in Outer Solar System

From Quarks to Quasars ^ | January 16, 2015 | James Trosper

[lbryce]

Presently, our solar system is known to contain 4 fully-fledged rocky worlds: Mercury, Venus, Earth and Mars; 2 ice-giants: Neptune and Uranus; 2 gas-giants, Saturn and Neptune; 5 dwarf-planets, Ceres. Pluto, Eris, MakeMake, Haumea; around 100 moons; and an unknowable number of comets, asteroids and minor planets. Indeed, we’ve only begun to understand the full scope of our local corner of our galaxy, and new information emerges on a monthly-basis, yet there a number of seemingly obvious things that remain unknown.

For instance, long before Pluto’s existence was deduced, astronomers scoured the outer solar system in search of another large planet, which, they believed, would explain many peculiarities surrounding the outermost planet and beyond. These peculiarities mostly center on the strange distribution of objects in the Kuiper belt — the cold, icy region between Neptune and the Oort Cloud — and how their orbits are more eccentric than expected.

Both oddities seem to suggest a planet lurks in the shadows, so large, it has an effect on distribution of rocky objects, and the orbit of each of them. It’s certainly not a new idea. In fact, this is just one of several iterations of the ‘missing planet’ hypothesis. Others postulate that instead of a hidden planet, one was flung from our solar system early on, before it settled into its final configuration (another hypothesizes that the Sun has a low-mass companion somewhere). All however, remain speculative since no true observational evidence has surface.

[lbryce]

One of the basic reasons why these huge planets have not been as of yet discovered has to do simply with the huge distances in which these planets orbit the sun. With planets closer to the sun, it is easier to locate them due to the fact that they reflect sunlight back to us. But in cases where the planets, while they may be huge, the ability to spot them via reflection of sunlight has been severely diminished due to the huge distances in which these planets orbit around the sun far greater than the furthest planets like Pluto. So lack of reflected sunlight is the number one reason these planets remain unknown. There are other indications of a huge planet way out there due to affected asteroids and other objects that do not follow the flight plain simply based on what we have. And so , the unpredictable orbits are being blamed on the giant planet yet remains unseen due to lack of reflective sunlight.