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.Continue reading “2029 Will be the Perfect Year to Launch a Mission to Sedna”
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.Continue reading “What Happens to Interstellar Objects Captured by the Solar System?”
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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.Continue reading “Astronomers Have Found Planet 9… in Another Solar System”
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.Continue reading “The Sun Might Have Once Had a Binary Companion Star”
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.Continue reading “If Planet 9 is a Primordial Black Hole, We Might Be Able to See Flares When it Consumes Comets”
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?Continue reading “Maybe the Elusive Planet 9 Doesn’t Exist After All”
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.
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.
Planet Nine, the massive orb proposed to explain the clustered orbits of a half dozen remote Kuiper Belt asteroids, may have a darker side. Periodic mass extinctions on Earth, as indicated in the global fossil record, could be linked to the hypothetical planet according to research published by Daniel Whitmire, a retired professor of astrophysics and faculty member of the University of Arkansas Department of Mathematical Sciences.
Planet Nine is estimated to be 10 times more massive than Earth and currently orbiting about 1,000 times farther away from the Sun. Astronomers have been searching for a potential large planet — for years called “Planet X” — that might be implicated in a handful of major mass extinctions over the past 500 million years. During those times, between 50 and more than 90% of species on Earth perished in a geological heartbeat. The worst, dubbed the Permian-Triassic event or the Great Dying, occurred 250 million years ago and saw the disappearance of more than 90% of the planet’s life in a geological heartbeat.
Whitmire and his colleague, John Matese, first published research on the connection between Planet X and mass extinctions in the journal Nature in 1985 while working as astrophysicists at the University of Louisiana at Lafayette. They proposed that perturbations from a 10th planet (Pluto was considered a planet back then) could fling a shower of comets from the Kuiper Belt beyond Neptune in Earth’s direction every 28 million years in sync with recorded mass extinctions.
Two other ideas also proposed at the time they wrote their paper — a sister star to the Sun and vertical oscillations of the Sun as it orbits the galaxy — have since been ruled out because the timing is inconsistent with the extinction record. Only Planet X remained as a viable theory, and it’s now gaining renewed attention.
Neil deGrasse Tyson explains precession and Mercury’s orbit
Whitmire and Matese proposed that as Planet X orbits the Sun, its tilted orbit slowly rotates, causing the location of its perihelion (closest point to the Sun) to slowly precess or shift position along its orbit instead of remaining in the same place. Every planet precesses, so no surprises here.
But location can make a huge difference. The team proposed that Planet X’s slow orbital gyration directs it into the Kuiper Belt approximately every 27 million years, knocking comets into the inner Solar System. The dislodged comets not only smash into the Earth, they also vaporize and break apart in the inner Solar System as they get nearer to the Sun, reducing the amount of sunlight that reaches the Earth. Add it up, and you have a recipe for cyclic destruction.
One thing to keep in mind is that their research led them to conclude that Planet X was only 5 times as massive as Earth and 100 times farther from the Sun. This doesn’t jive with the size and mass particulars for Planet Nine inferred by researchers Konstantin Batygin and Michael E. Brown at Caltech earlier this year, but until someone tracks the real planet down, there’s room for argument.
Comet and asteroid showers are often cited as possible bad guys in extinction episodes. And why not? We have hard evidence of the asteroid impact that sealed the dinosaurs’s fate 65 million years ago and have seen some six impacts at Jupiter since 1994. It’s cosmic billiards out there folks, and the game’s not over.
Host: Fraser Cain (@fcain)
Their stories this week:
Mysterious Fast Radio Bursts Solve Missing Baryon Problem
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