Caltech Astronomers Say a Ninth Planet Lurks Beyond Pluto (sciencemag.org)

sciencehabit writes: The solar system may have a new ninth planet. Today, two scientists announced evidence that a body nearly the size of Neptune — but as yet unseen — orbits the sun every 15,000 years. During the solar system's infancy 4.5 billion years ago, they say, the giant planet was knocked out of the planet-forming region near the sun. Slowed down by gas, the planet settled into a distant elliptical orbit, where it still lurks today. Here's a link to the full academic paper published in The Astronomical Journal.

Comments

Re:Well, I guess we'll know in a few thousand year

[Rei]

Not really. There's going to be some very powerful telescopes involved in survey work coming online over the course of the next decade that should dramatically increase our detection capability. My favorite is the LSST which should, for example, move from our current knowledge of about 1% of 100km+ KBOs to nearly 100%. And one can expect even more powerful telescopes in the decades after that.

Next decade, whenever anything is detected, we'll also have James Webb to get a better look at it.

Re:Does it count as "evidence"

[avgjoe62]

You really need to read the articles. To quote from one of them:

But the real kicker for the researchers was the fact that their simulations also predicted that there would be objects in the Kuiper Belt on orbits inclined perpendicularly to the plane of the planets. Batygin kept finding evidence for these in his simulations and took them to Brown. "Suddenly I realized there are objects like that," recalls Brown. In the last three years, observers have identified four objects tracing orbits roughly along one perpendicular line from Neptune and one object along another. "We plotted up the positions of those objects and their orbits, and they matched the simulations exactly," says Brown. "When we found that, my jaw sort of hit the floor."

"When the simulation aligned the distant Kuiper Belt objects and created objects like Sedna, we thought this is kind of awesome—you kill two birds with one stone," says Batygin. "But with the existence of the planet also explaining these perpendicular orbits, not only do you kill two birds, you also take down a bird that you didn't realize was sitting in a nearby tree."

Re:Does it count as "evidence"

[pz]

If you read the article (I know, I know), you'll learn that there are, in fact, observables involved. There are a handful of Kuiper Belt objects that have an odd level of similarity among them, so odd that the only ready explanation is that there is an as-yet unseen object shepherding them. The Caltech group created a simulation of the kind of object that might produce such a result and found that it ALSO would be expected to shepherd a second set of smaller objects into orbits orthogonal to the ecliptic. Very, very strange. So they made that prediction, and LO! found objects that fit the bill.

They created a theory based on observational evidence. The theory made a prediction that was tested, and found correct. The body itself has not been observed, yet, but I'd expect that the Japanese will find it (given that, according to other news articles), they have just the right sort of telescope to perform the search.