Space

The Solar System may really have nine planets

Artist's concept of the hypothetical ninth planet
Artist's concept of the hypothetical ninth planet
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Predicted orbits of objects that may be associated with the hypothetical ninth planet
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Predicted orbits of objects that may be associated with the hypothetical ninth planet
Artist's concept of the hypothetical ninth planet
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Artist's concept of the hypothetical ninth planet
Orbit of the hypothetical ninth planet
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Orbit of the hypothetical ninth planet
Caltech professor Mike Brown and assistant professor Konstanin Batygin, who developed the ninth planet hypothesis
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Caltech professor Mike Brown and assistant professor Konstanin Batygin, who developed the ninth planet hypothesis

There's good news for those who were annoyed when Pluto was knocked off the list of planets. According to a pair of scientists at Caltech, there may actually be nine planets in the Solar System after all. Researchers Konstantin Batygin and Mike Brown say that a planet ten times the mass of Earth may be circling the Sun in a highly elliptical orbit 20 times the distance of Neptune or 36 billion mi (60 billion km), with a year of 10,000 to 20,000 Earth years.

Caltech says that the still-hypothetical planet has yet to be observed and that its existence is based on mathematical modeling and computer simulations derived from the orbits of six Kuiper Belt objects in the outer Solar System. These objects have very unusual orbits that are tilted 30º to the plane of the ecliptic, where the eight known planets reside, and all point in the same direction.

Batygin and Brown say that this could be due to the presence of a previously-unknown planet or a mass of Kuiper Belt objects. However, the latter was dismissed because it would require the belt to be a hundred times more massive that it's believed to be. In addition, the movements of the other planets could not explain the phenomenon because the planetary orbits are too irregular in relation to one another to cause the tilt and alignments.

Orbit of the hypothetical ninth planet
Orbit of the hypothetical ninth planet

To determine whether an unknown planet was involved, Batygin and Brown assumed that it has a perihelion (closest distance to the Sun) that was 180º out of synch with the other planets or other known objects. Their calculations indicated that a ninth planet would set up a state called a mean-motion resonance, that keeps the six Kuiper Belt Objects stable and prevents them from colliding with one another.

In addition to explaining the six Kuiper Belt objects, Batygin and Brown discovered that their hypothesis also explains orbital anomalies of Kuiper objects Sedna and 2012 VP113, and predicted the presence of Kuiper objects perpendicular to the ecliptic – four of which have been observed in the last three years.

The scientist believe that the presence of the ninth planet could shed light on the origin of the Solar System by indicating the existence of a fifth "core" to the theorized four around which the gas and dust of the early system may have condensed to form the planets Jupiter, Saturn, Uranus, and Neptune. They say that this fifth core could have been ejected by Jupiter or Saturn to form the ninth planet, which may explain its highly eccentric orbit.

Caltech professor Mike Brown and assistant professor Konstanin Batygin, who developed the ninth planet hypothesis
Caltech professor Mike Brown and assistant professor Konstanin Batygin, who developed the ninth planet hypothesis

The Caltech team says that despite its great distance, larger earthbound telescopes should be able to see the Neptune-like planet and they hope that their announcement will spur a hunt for it. In addition, Brown, who was instrumental in having Pluto downgraded to a dwarf planet, hopes that the news will help un-ruffle some feathers.

"All those people who are mad that Pluto is no longer a planet can be thrilled to know that there is a real planet out there still to be found," says Brown. "Now we can go and find this planet and make the solar system have nine planets once again."

The Caltech research was published in The Astronomical Journal.

In the video below, Batygin and Mike Brown discuss their findings.

Source: Caltech

Evidence of a Ninth Planet

17 comments
inchiki
If this planet shows up where they think it is, these two are headed for the history books. It would be the most exciting astronomical discovery for 100 years perhaps.
gizmowiz
It would take Terminator to visit it which at 10 times Earth's gravity a man would weight 2,000 lbs and crush his spine not to mention break his legs and more trying to stand up. So no 'one small step for a man, one giant leap for mankind' will be taking place on this planet even if it's got a rocky surface!
Schreibtribe
Wow, cool! Thanks for the great reporting Gizmag, you guys are on point
Chizzy
Hope they give it a name starting with P, so all my planetary mnemonics still work. my very educated mother just served us nine pickles
Bob Stuart
I like my planets to have nearly circular, non-crossing orbits.
JohnE.Durrett
The idea is not new, its called Niburu and been around for ages.
IDNTBF
Nibiru! But for Chizzy, and the rest of us, the should call it "Pan", "Poseidon", "Prometheus" or "Psyche" I like "Psyche."
VirginiaKeller
If it's Neptune size/mass it wouldn't have that kind of gravity, inchiki. "How strong is the gravity on Neptune? Although Neptune is much larger than Earth, its surface gravity is about the same as the surface gravity on Earth. This is because Neptune is made up of gases and is not solid like Earth. This makes Neptune very light for its size. The surface gravity on Neptune is about 110% of the surface gravity on Earth, so if you weigh 100 pounds on Earth, you would weigh 110 pounds on Neptune (assuming you could find someplace to, well, stand)." http://coolcosmos.ipac.caltech.edu/ask/142-How-strong-is-the-gravity-on-Neptune-
CliffG
I'm sorry Prof. Brown, I'm still annoyed - my feathers remain ruffled. Pluto was my favorite planet and in spite of your chicanery, it still is. Your hypothetical planet nine is - - well - - purely hypothetical and furthermore, if it does someday materialize, you are still will remain in my astronomical dog house. I suggest a boycott of hypothetical planet nine. If you want to see the ninth planet, then train your telescope instead to Pluto.
MichiganDave
Personally, I want the new planet to be named "DAVE. I think it sounds really catchy myself.
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