Free Republic

“If Planet Nine is real, it would be on such an odd orbit and so far out in the outer Solar System, that it would really challenge our ideas of planet formation and dynamics,” Ann-Marie Madigan, assistant professor of astrophysics... Madigan isn’t searching for just one planet — she’s looking for an entire belt of celestial objects. Like Planet Nine, this proposed Zderic-Madigan, or ZM, belt would be really out there, far beyond the Kuiper belt, with some of its closest bodies being more than twice as far from the Sun as Pluto at perihelion. Unlike the Kuiper belt, this...

Over the past few years, researchers have noticed an odd clustering in the orbits of multiple trans-Neptunian objects (TNOs), which dwell in the dark depths of the far outer solar system. Some scientists have hypothesized that the TNOs' paths have been sculpted by the gravitational pull of a big object way out there, something five to 10 times more massive than Earth (though others think the TNOs may just be tugging on each other). This big "perturber," if it exists, may be a planet — the so-called "Planet Nine," or "Planet X" or "Planet Next" for those who will always...

Periodic mass extinctions on Earth, as indicated in the global fossil record, could be linked to a suspected ninth planet, according to research published by a faculty member of the University of Arkansas Department of Mathematical Sciences. Daniel Whitmire, a retired professor of astrophysics now working as a math instructor, published findings in the January issue of Monthly Notices of the Royal Astronomical Society that the as yet undiscovered "Planet X" triggers comet showers linked to mass extinctions on Earth at intervals of approximately 27 million years. Though scientists have been looking for Planet X for 100 years, the possibility...

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...

In their studies, the team analyzed the effects of what is called the ‘Kozai mechanism,’ which is related to the gravitational perturbation that a large body exerts on the orbit of another much smaller and further away object. They looked at how the highly eccentric comet 96P/Machholz1 is influenced by Jupiter (it will come near the orbit of Mercury in 2017, but it travels as much as 6 AU at aphelion) and it may “provide the key to explain the puzzling clustering of orbits around argument of perihelion close to 0° recently found for the population of ETNOs,” the team...