Planet 9 Archives

October 6, 2023October 6, 2023 by Andy Tomaswick

Could Modified Gravity Be the Answer to Planet 9?

As students advance to higher and higher physics courses, they eventually learn that the simple Newtonian dynamics they learned about in early classes aren’t completely accurate models for understanding the universe. If things get too big or fast, they fall into the realm of relativity, or if they get too small, they get caught up in quantum mechanics. However, simple Newtonian dynamics does the trick for things ranging from how a baseball flies to how planets orbit the Sun.

February 20, 2023February 20, 2023 by Nancy Atkinson

If Planet 9 has Moons, Would That Help Us Find It?

Artist's concept of the hypothetical "Planet Nine." Could it have moons? Credit: NASA/JPL-Caltech/Robert Hurt

Planet 9 continues to remain elusive. This potential super-Earth-sized object in the outer Solar System is only hypothetical, as something out there appears to be gravitationally influencing several Kuiper Belt Objects into unusual orbits. Whatever or wherever it may be, Planet 9 has yet to be found, despite several different hypotheses and numerous observational searches.

But what if Planet 9 has moons? Could they help us find it? A new paper speculates that any moons orbiting the theoretical planet could provide indirect clues to the location of Planet 9, while revealing some basic properties of this mysterious object.

September 13, 2022September 15, 2022 by Laurence Tognetti

Flying to (Hypothetical) Planet 9: Why visit it, how could we get there, and would it surprise us like Pluto?

In a recent study submitted to Earth and Planetary Astrophysics, an international team of researchers discuss the various mission design options for reaching a hypothetical Planet 9, also known as “Planet X”, which state-of-the-art models currently estimate to possess a semi-major axis of approximately 400 astronomical units (AU). The researchers postulate that sending a spacecraft to Planet 9 could pose scientific benefits much like when NASA’s New Horizons spacecraft visited Pluto in 2015. But does Planet 9 actually exist?

July 31, 2022July 31, 2022 by Brian Koberlein

Planet 9 is Running out of Places to Hide

Illustration of the hypothetical Planet 9. Credit: R. Hurt/IPAC, Caltech

We have a pretty good idea of what lurks within our solar system. We know there isn’t a Mars-sized planet orbiting between Jupiter and Saturn, nor a brown dwarf nemesis heading our way. Anything large and fairly close to the Sun would be easily spotted. But we can’t rule out a smaller, more distant world, such as the hypothetical Planet 9 (or Planet 10 if you want to throw down over Pluto). The odds against such a planet existing are fairly high, and a recent study finds it even less likely.

September 15, 2021September 15, 2021 by Matt Williams

A 6-Year Search of the Outer Solar System Turns up 461 new Objects (but no Planet 9)

Artist's concept of the New Horizons spacecraft encountering a Kuiper Belt object, part of an extended mission after the spacecraft’s July 2015 Pluto flyby. Credits: NASA/JHUAPL/SwRI

In the near future, astronomers will benefit from the presence of next-generation telescopes like the James Webb Space Telescope (JWST) and the Nancy Grace Roman Space Telescope (RST). At the same time, improved data mining and machine learning techniques will also allow astronomers to get more out of existing instruments. In the process, they hope to finally answer some of the most burning questions about the cosmos.

For instance, the Dark Energy Survey (DES ), an international, collaborative effort to map the cosmos, recently released the results of their six-year survey of the outer Solar System. In addition to gathering data on hundreds of known objects, this survey revealed 461 previously undetected objects. The results of this study could have significant implications for our understanding of the Solar System’s formation and evolution.

July 10, 2020July 10, 2020 by Evan Gough

If Planet 9 is a Primordial Black Hole, We Might Be Able to See Flares When it Consumes Comets

Artist's conception of accretion flares resulting from the encounter of an Oort-cloud comet and a hypothesized black hole in the outer solar system. Credit: M. Weiss

A comet-eating black hole the size of a planet? It’s possible. And if there’s one out there in the distant Solar System, a pair of researchers think they know how to find it.

If they do, we might finally put the Planet 9 issue to rest.

May 29, 2020May 29, 2020 by Evan Gough

Maybe the Elusive Planet 9 Doesn’t Exist After All

The imagined view from Planet Nine looking back toward the sun. Astronomers think the huge, distant planet is gaseous, similar to the other giant planets in our solar system.

Oh Planet Nine, when will you stop toying with us?

Whether you call it Planet Nine, Planet X, the Perturber, Jehoshaphat, “Phattie,” or any of the other proposed names—either serious or flippant—this scientific back and forth over its existence is getting exhausting.

Is this what it was like when they were arguing whether Earth is flat or round?

March 1, 2019March 1, 2019 by Evan Gough

More Evidence that Planet 9 is Really Out There

Artist's impression of Planet Nine as an ice giant eclipsing the central Milky Way, with a star-like Sun in the distance. Neptune's orbit is shown as a small ellipse around the Sun. The sky view and appearance are based on the conjectures of its co-proposer, Mike Brown. Image Credit: By nagualdesign; Tom Ruen, background taken from File:ESO - Milky Way.jpg - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=47069857

What’s going on in the distant reaches of our Solar System? Is there a Planet 9 out there?

Out in the frigid expanse of our System, there are bodies on orbital paths that don’t make sense in terms of our eight-planet Solar System. There seems to be an undiscovered body out there, several times more massive than Earth, shaping the orbits of some Kuiper Belt Objects (KBOs), and driving astronomers to look deeper and more thoroughly into the extreme reaches of our System.

What they’re looking for is the mysterious, and so far unproven, ninth planet.

February 27, 2019February 27, 2019 by Evan Gough

The Record for the Most Distant Object in the Solar System has been Shattered. Introducing FarFarOut at 140 Astronomical Units

Artist concept of 2018 VG18 "Farout". Credit Roberto Molar Candanosa/Carnegie Institution for Science.

Remember Far Out, the distant planet at the far reaches of the Solar System, that was discovered in December, 2018? Well, it has been kicked unceremoniously off its pedestal as the most distant object after a short, two-month reign. In its place is the very newly-discovered FarFarOut (FFO.)

And if it weren’t for a heavy snowfall, things might have turned out differently.

January 23, 2019January 23, 2019 by Evan Gough

A Disc of Icy Material, not Planet 9, Might Explain the Strange Movements in the Outer Solar System

Could a disk of icy material be responsible for the strange orbits of distand objects in our Solar System? Image Credit: ESO/M. Kornmesser

Is there or isn’t there a Planet 9? Is there a planet way out on the outskirts of our Solar System, with sufficient mass to explain the movements of distant objects? Or is a disc of icy material responsible? There’s no direct evidence yet of an actual Planet 9, but something with sufficient mass is affecting the orbits of distant Solar System objects.

A new study suggests that a disc of icy material causes the strange movements of outer Solar System objects, and that we don’t need to invent another planet to explain those movements. The study comes from
Professor Jihad Touma, from the American University of Beirut, and
Antranik Sefilian, a PhD student in Cambridge’s Department of Applied Mathematics and Theoretical Physics. Their results are published in the Astronomical Journal.