Caltech Researchers Find Evidence of a Real Ninth Planet
Jared Sperli stashed this in space
Stashed in: The Universe, Awesome, New Yorker, Caltech, Space!, Pluto
Scientists Discover "Most Planet-y" Planet in the Solar System:
Oh FFS. We just demoted Pluto because it was too small and didn't do a real planet's job of taking out the orbital trash, but now the boffins at Caltech are claiming we have a ninth planet after all. It's a gazillion miles away, but apparently it's big enough to "clear the neighborhood" and thus qualify as a real planet
More:
http://www.usatoday.com/story/news/nation/2016/01/20/researchers-discover-planet-nine/79056118/
Caltech Researchers Find Evidence of a Real Ninth Planet
Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles). In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the sun.The researchers,
Konstantin Batygin and Mike Brown, discovered the planet's existence through mathematical modeling and computer simulations but have not yet observed the object directly."This would be a real ninth planet," says Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy. "There have only been two true planets discovered since ancient times, and this would be a third. It's a pretty substantial chunk of our solar system that's still out there to be found, which is pretty exciting."
Brown notes that the putative ninth planet—at 5,000 times the mass of Pluto—is sufficiently large that there should be no debate about whether it is a true planet. Unlike the class of smaller objects now known as dwarf planets, Planet Nine gravitationally dominates its neighborhood of the solar system. In fact, it dominates a region larger than any of the other known planets—a fact that Brown says makes it "the most planet-y of the planets in the whole solar system."
Batygin and Brown describe their work in the current issue of the Astronomical Journal and show how Planet Nine helps explain a number of mysterious features of the field of icy objects and debris beyond Neptune known as the Kuiper Belt.
Source:
https://facebook.com/groups/19637771840/permalink/10153129925326841/
http://caltech.edu/news/caltech-researchers-find-evidence-real-ninth-planet-49523
This is an exciting finding.
What Dr. Brown and a fellow Caltech professor, Konstantin Batygin, have not done is actually find that planet, so it would be premature to start revising mnemonics of the planets.
In a paper published in The Astronomical Journal, Dr. Brown and Dr. Batygin laid out a detailed circumstantial argument for the planet’s existence in what astronomers have observed: a half-dozen small bodies in distant elliptical orbits.
What is striking, the scientists said, is that the orbits of all six loop outward in the same quadrant of the solar system and are tilted at about the same angle. The odds of that happening by chance are about 1 in 14,000, Dr. Batygin said.
A ninth planet could be gravitationally herding them into these orbits.
For the calculations to work, the planet would be at least an equal to Earth, and most likely much bigger — perhaps a mini-Neptune, with a small but thick atmosphere surrounding a rocky core and mass about 10 times that of Earth. That would be 4,500 times the mass of Pluto.
Pluto, at its most distant, is 4.6 billion miles from the sun. The potential ninth planet, at its closest, would be about 20 billion miles away; at its farthest, it could be 100 billion miles away. One trip around the sun would take 10,000 to 20,000 years.
“We have pretty good constraints on its orbit,” Dr. Brown said. “What we don’t know is where it is in its orbit, which is too bad.”
Alessandro Morbidelli of the Côte d’Azur Observatory in France, an expert in dynamics of the solar system, said he was convinced. “I think the chase is now on to find this planet,” he said.
Continue reading the main story
This would be the second time that Dr. Brown has upended the map of the solar system. In January 2005, he discovered a Pluto-size object, now known as Eris, in the Kuiper belt, the ring of icy debris beyond Neptune.
The next year, the International Astronomical Union placed Pluto in a new category, “dwarf planet,” because in its view, a full-fledged planet must be the gravitational bully of its orbit, and Pluto was not.
The first indication of a hidden planet beyond Pluto had come a couple of years earlier. The Kuiper belt extends outward from Neptune’s orbit, about 2.8 billion miles from the sun, to a bit less than twice Neptune’s orbit, about five billion miles.
Astronomers expected that beyond lay mostly empty space.
Thus, they were surprised when Dr. Brown and two colleagues spotted a 600-mile-wide icy world at a distance of eight billion miles that remained well outside the Kuiper belt even at the closest point in its orbit.
No one could convincingly explain how the object, which Dr. Brown named Sedna, got there, and the hope was that the discovery of more Sedna-like worlds would provide enlightening clues.
Instead, astronomers looked and found nothing, deepening the mystery.
Finally, in 2014, Chadwick Trujillo, who had worked with Dr. Brown on the Sedna discovery, and Scott S. Sheppard, an astronomer at the Carnegie Institution for Science in Washington, reported a smaller object in a Sedna-like orbit, always remaining beyond the Kuiper belt.
Dr. Trujillo and Dr. Sheppard noted that several Kuiper belt objects had similar orbital characteristics, and they laid out the possibility of a planet disturbing the orbits of these objects. “It was the best explanation we could come up with,” Dr. Trujillo said.
Source:
http://www.nytimes.com/2016/01/21/science/space/ninth-planet-solar-system-beyond-pluto.html
Call it Planet X: http://sciencemag.org/news/2016/01/feature-planet-x
Primary source: http://iopscience.iop.org/article/10.3847/0004-6256/151/2/22/meta
2000 Reddit comments:
https://reddit.com/r/science/comments/41up8u/astronomers_have_announced_the_potential/
9:14 PM Jan 20 2016