Planet Nine Archives

February 17, 2024February 17, 2024 by Laurence Tognetti

There’s One Last Place Planet 9 Could Be Hiding

Artist's illustration of Planet Nine with the Sun and orbit of Neptune (ring) in the distance. (Credit: ESO/Tomruen/nagualdesign)

A recently submitted study to The Astronomical Journal continues to search for the elusive Planet Nine (also called Planet X), which is a hypothetical planet that potentially orbits in the outer reaches of the solar system and well beyond the orbit of the dwarf planet, Pluto. The goal of this study was to narrow down the possible locations of Planet Nine and holds the potential to help researchers better understand the makeup of our solar system, along with its formation and evolutionary processes. So, what was the motivation behind this study regarding narrowing down the location of a potential Planet Nine?

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?

January 1, 2022January 1, 2022 by Scott Alan Johnston

2029 Will be the Perfect Year to Launch a Mission to Sedna

Artist's conception of Sedna, the TNO that orbits in the outer edges of the Solar System. Credit: NASA/JPL-Caltech

Object 90377 Sedna – a distant trans-Neptunian object known best for its highly elliptical, 11,390-year long orbit – is currently on its way towards perihelion (its closest approach to the Sun) in 2076. After that, Sedna will swing out into deep space again and won’t be back for millennia, making this flyby a once-in-a-lifetime (or, once in ~113 lifetimes) opportunity to study an object from the far reaches of our solar system. There are no missions to Sedna in the works just yet, but astronomers are beginning to plan for the possibility, and the ideal launch date for such a mission is approaching fast, with two of the best launch windows coming up in 2029 and 2034.

September 27, 2021September 27, 2021 by Evan Gough

What Happens to Interstellar Objects Captured by the Solar System?

An artist’s overview of the mission concept for the Comet Interceptor spacecraft. Credit: ESA

Now that we know that interstellar objects (ISOs) visit our Solar System, scientists are keen to understand them better. How could they be captured? If they’re captured, what happens to them? How many of them might be in our Solar System?

One team of researchers is trying to find answers.

December 17, 2020December 17, 2020 by Evan Gough

Astronomers Have Found Planet 9… in Another Solar System

This 11-Jupiter-mass exoplanet called HD106906 b occupies an unlikely orbit around a double star 336 light-years away and it may be offering clues to something that might be much closer to home: a hypothesized distant member of our Solar System dubbed “Planet Nine.” This is the first time that astronomers have been able to measure the motion of a massive Jupiter-like planet that is orbiting very far away from its host stars and visible debris disc. Image Credit: ESA/Hubble, M. Kornmesser

Even with all we’ve learned about our own Solar System, especially in the last couple of decades, researchers still face many unanswered questions. One of those questions regards the so-called Planet Nine. The Planet Nine hypothesis states that there’s a massive planet in our Solar System orbiting at a great distance from the Sun.

Nobody’s ever observed the hypothesized planet; the evidence for it lies in a cluster of bodies that orbit the Sun 250 times further out than Earth does. These objects are called e-TNOs, for extreme Trans-Neptunian Objects. According to the hypothesis, Planet Nine’s gravity is responsible for the unusual clustered orbits of these e-TNOs.

Now astronomers have found a distant solar system with its own Planet Nine, and that discovery is breathing new life into the hypothesis.

August 19, 2020August 19, 2020 by Matt Williams

The Sun Might Have Once Had a Binary Companion Star

For some time now, astronomers have known that the majority of systems in our galaxy consist of binary pairs rather than individual stars. What’s more, in recent decades, research has revealed that stars like our Sun are actually born in clusters within solar nebulas. This has led to efforts in recent years to locate G-type (yellow dwarf) stars in our galaxy that could be the Sun’s long-lost “solar siblings.”

And now, a new study by Harvard astronomers Amir Siraj and Prof. Abraham Loeb has shown that the Sun may once have once had a very similar binary companion that got kicked out of our Solar System. If confirmed, the implications of this could be groundbreaking, especially where theories on how the Oort Cloud formed and whether or not our system captured a massive object (Planet Nine) in the past.

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?

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.

April 4, 2016May 31, 2016 by Jason Major

Did the Sun Steal Planet Nine?

Artist's impression of Planet Nine, blocking out the Milky Way. The Sun is in the distance, with the orbit of Neptune shown as a ring. Credit: ESO/Tomruen/nagualdesign

One of the biggest new mysteries in our Solar System is the purported presence of a large and distant “Planet Nine,” traveling around the Sun in a twenty-thousand-year orbit far beyond Pluto. Although this far-flung world’s existence has yet to actually be confirmed (or even directly detected) some scientists are suggesting it might have originally been an exoplanet around a neighboring star, pilfered by our Sun during its impudent adolescence.

Continue reading “Did the Sun Steal Planet Nine?”