The sample size of icy rocks that appear to have their orbits affected by a Neptune-like "Planet Nine" is growing larger:
For the past few years, [Scott] Sheppard of [the Carnegie Institution for Science], [Chadwick] Trujillo [of Northern Arizona University] and David Tholen of the University of Hawaii have been hunting for objects in the far outer solar system using several different instruments, including the Subaru Telescope in Hawaii and the Dark Energy Camera, which is installed on a 4-meter telescope at the Cerro Tololo Inter-American Observatory in Chile. [...] The astronomers discovered several dozen previously unknown bodies, including a roughly 155-mile-wide (250 km) object called [2014 FE72] that gets an incredible 4,000 AU from the sun at its most distant point. That puts it out in the outer Oort Cloud — the realm of comets.
[...] They also discovered two 125-mile-wide (200 km) objects, known as 2014 SR349 and 2013 FT28, that "cluster" in one of the key orbital parameters (known as argument of perihelion), furthering strengthening the case for Planet Nine's existence. (The objects' names reflect the years that they were first spotted in the survey; their discovery is being announced in the new study.) "We have 15 or so of these extreme objects now, and all of them cluster in this argument of perihelion angle," Sheppard said.
Furthermore, he added, the five most distant of these 15 extreme objects share similarities in another orbital characteristic as well, one called longitude of perihelion. Significantly, the far-flung five are too distant to be realistically affected by any gravitational tugs from Neptune (whose influence could be the reason the other 10 objects' longitudes of perihelion don't line up). It would take just two or three more such additional finds to put Planet Nine on solid ground, Sheppard said. "I think statistics-wise, in the next year to two years we'll probably find enough of these small, extreme objects to really say if Planet X exists or not," he said. [...] "We need like 10 or 20 of these smaller extreme objects, and we can probably nail down much better where Planet X would be out there," Sheppard said.
2014 SR349, 2013 FT28, and 2014 FE72.
Also at the Carnegie Institution for Science.
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NASA is collaborating with Zooniverse to allow the public to search WISE data for "nearby" rogue planets, brown dwarfs, and Planet Nine:
NASA is inviting the public to help search for possible undiscovered worlds in the outer reaches of our solar system and in neighboring interstellar space. A new website, called Backyard Worlds: Planet 9, lets everyone participate in the search by viewing brief movies made from images captured by NASA's Wide-field Infrared Survey Explorer (WISE) mission. The movies highlight objects that have gradually moved across the sky.
"There are just over four light-years between Neptune and Proxima Centauri, the nearest star, and much of this vast territory is unexplored," said lead researcher Marc Kuchner, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Because there's so little sunlight, even large objects in that region barely shine in visible light. But by looking in the infrared, WISE may have imaged objects we otherwise would have missed."
Previously: No Evidence for 'Planet X', says NASA - "[No] object the size of Saturn or larger exists out to a distance of 10,000 astronomical units (AU), and no object larger than Jupiter exists out to 26,000 AU."
NASA's WISE Spacecraft Discovers Most Luminous Galaxy in Universe
NASA's NEOWISE Mission Finds 72 Additional Near-Earth Objects
Two New Kuiper Belt Objects Boost the Case for "Planet Nine"
The Mysterious 'Planet Nine' Might be Causing the Whole Solar System to Wobble
(Score: -1, Troll) by Anonymous Coward on Wednesday August 31 2016, @09:15AM
It's not real space news without Musky.
(Score: 0) by Anonymous Coward on Wednesday August 31 2016, @11:18AM
...perhaps Planet X will turn out to be Dwarf Planet Nine.
(Score: 2, Informative) by jimtheowl on Wednesday August 31 2016, @01:07PM
"a hypothetical world larger than Earth that scientists are calling Planet Nine, or Planet X"
So, by definition, no.
In summary:
".. the gravitational influence of a roughly 10-Earth-mass planet about 600 AU from the sun could indeed explain the odd "clustering" in the orbits of Sedna, 2012 VP113 and a handful of other distant objects"
(Score: 1, Interesting) by Anonymous Coward on Wednesday August 31 2016, @01:40PM
By definition, if it hasn't "cleared the neighborhood" of other objects, it's a dwarf planet--no matter how massive it is.
(Score: 1, Insightful) by Anonymous Coward on Wednesday August 31 2016, @02:00PM
It looked to me like the proposed orbit was clear. These Kuiper belt objects do not share the same orbit as Nemesis or whatever we'll call it (if it's out there). This diagram [wikipedia.org] is more clear than the one in TFA.
(Score: 3, Interesting) by bzipitidoo on Wednesday August 31 2016, @01:57PM
4000 AU, huh? How far away can a planet be and have good odds of remaining in orbit for the life of its star, and not be flung out by a close encounter with a passing system?
Checking, I learned there is no limit to the distance an object can orbit another. I suppose that's basic astronomy. Escape velocity is always sqrt(2) times orbital velocity, for circular orbits, no matter how far away the orbit is. In intergalactic space, there could be planets in orbits of several light years distance around lone stars. (A light year is roughly 63k AU.) Seems the only limit to orbital distance is the odds of having a close encounter with another large object.
(Score: 1, Interesting) by Anonymous Coward on Wednesday August 31 2016, @02:10PM
That sort of leads into just how "vastly, hugely, mind-bogglingly big" space is. Proxima Centauri is 266,757 AU out (4.218 ly). I would assume the odds are astonishingly small that some rogue object or a star with a weird orbit would come close enough to affect Planet X.
(Score: 2) by bob_super on Wednesday August 31 2016, @05:13PM
According to Hollywood, it will happen, and change its orbit such that a collision with Earth is inevitable unless a group of courageous Americans, sent by Margan freeman and led by Vin Diesel and whoever can provide the most spacesuit cleavage, apply the solution at the last second.
Which they will, but only after both Saturn and Jupiter get destroyed about an hour apart, with some really cool ring-warp special effects oddly oblivious of their actual size.
In the second episode years later, you'll learn that the orbit change was cause by a disgruntled retired NASA scientist who was derided when he claimed to have invented faster-than-c propulsion, stole a gravity gun and set up an outpost at the Sun-Proxima L1 point... Starring Jude Law and Britney Spears, direct to DVD.
(Score: 2) by butthurt on Wednesday August 31 2016, @10:45PM
Unless, of course, Nemesis exists!
The Nemesis theory was devised to account for this regularity in the timing of the mass extinctions reported by Raup and Sepkoski. According to this model, a companion star orbiting the Sun perturbs the Oort comet cloud every 26 Myr causing comet showers in the inner solar system. One or more of these comets strike the Earth causing a mass extinction.
--http://muller.lbl.gov/pages/lbl-nem.htm [lbl.gov]
THE THEORIZED COMPANION STAR, THROUGH ITS GRAVITATIONAL PULL, UNLEASHES A FURIOUS STORM OF COMETS IN THE INNER SOLAR SYSTEM LASTING FROM 100,000 TO TWO MILLION YEARS. SEVERAL OF THESE COMETS STRIKE THE EARTH.
--http://www2.lbl.gov/Science-Articles/Archive/extinctions-nemesis.html [lbl.gov]
(Score: 1, Interesting) by Anonymous Coward on Thursday September 01 2016, @12:08AM
AC who referred to it as Nemesis here. That's what I was thinking of. Looking at that Wikipedia article, the orbital period of this Planet X would only be 15,000 years. Thanks for the links. I didn't know this (from muller.lbl.gov):
The expected orbit lifetime when the solar system was formed was (presumably) about 5.5 billion years. When nearby stars pass the solar system, the orbit of Nemesis is given slight boosts in energy. The Nemesis orbit becomes larger and less stable. At present, the Nemesis orbit has a semi-major axis of about 1.5 light-years, and the orbit is expected to remain bound to the sun for only another billion years.
Note that the Nemesis theory predicts that the periodicity should not be precise. Perturbations from passing stars are not sufficient to disrupt the orbit, but they are sufficient to cause a slight (a few Myr) jitter in the interval between extinctions.
(Score: 2) by dry on Thursday September 01 2016, @02:05AM
There's some big stars out there. How far away can a blue super-giant cause orbital perturbations? Come to that, how far would the deadly radiation zone be from a blue super-giant?
(Score: 1) by toddestan on Thursday September 01 2016, @02:56AM
Well, on the other side of things is how vastly, hugely, mind-bogglingly long the time is that the Sun will be around. Our sun has been around 4.5 billion years, which is something like 60 million human lifetimes. And it has another 4.5 billion years or so to go before the sun finally goes dark. That's a really, really long time for something to happen that could affect Planet X.