Showing all posts about Pluto
Planet Nine may not exist, but Dwarf Planet Nine might
26 June 2025
The apparent discovery of an extremely distant dwarf-planet, known as 2017 OF201, might put paid to the speculated existence of a likewise far-flung Neptune-size planet, often referred to as Planet Nine, says Isaac Schultz, writing for Gizmodo:
Which brings us, inevitably, to Planet Nine, the theorized distant world posited as a gravitational explanation for the strange clustering of objects in the Kuiper Belt. Other ideas have been floated to explain the phenomenon — such as a ring of debris exerting gravitational influence, or even a primordial black hole — but nothing grips our human fascination like a distant planet, so far away from our solar system’s other worlds that it’s never been observed.
Unexpected variations in the orbits of numerous dwarf-planets and various other bodies, known as Trans-Neptunian Objects (TNO), usually located beyond the orbit of Pluto, have long puzzled scientists and astronomers. This has lead some of them to believe the solar system hosts a larger planet, which they call Planet Nine.
This body possibly orbits the Sun elliptically, at an average distance of two-hundred-and-fifty astronomical units (AU), or thirty-seven billion KM (compared with an average six billion or so KM for Pluto), and takes ten to twenty thousand years to do so. But its theorised presence might account for the odd orbital behaviour of some TNOs.
But this is where things become intriguing. A 2013 NASA survey of the area surrounding the solar system, apparently detected no indication of any reasonably large planetary bodies beyond the orbit of Pluto. This despite the ability of their technology to perceive Saturn-size objects a tenth of a light year distant.
This discovery of 2017 OF201, which leisurely orbits the Sun once every twenty-five thousand years, and ventures as far away as sixteen-hundred AU, makes sense in this context. It also opens the door to locating potentially many more highly distant dwarf-planets.
The presence of 2017 OF201 however does not completely eliminate the possibility Planet Nine exists, the 2013 NASA study notwithstanding. Sihao Cheng, who participated in finding 2017 OF201, still hopes Planet Nine turns out to be there.
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In a world gone mad here is the clearest yet photo of Pluto
24 June 2025
This is — if anything you read on social media is accurate that is — the clearest ever photo of dwarf planet Pluto. The original set of images used to composite this one were taken ten years ago, when NASA‘s New Horizons space probe flew passed Pluto in July 2015.
By colour enhancing the image — Pluto doesn’t actually look quite so vivid — more detail is resolved, allowing for more information to be gleaned about the distant planetoid.
I’ve not been able to precisely ascertain when this image was first published. According to Project Ubu (Instagram page), in a post on Sunday 22 June 2025, NASA had “just released” the image. On hunting around, I found the same image on the Galaxies Instagram page, but they posted the photo on Friday 25 April 2025.
So the image certainly hasn’t been “just released”, I’d have gone for recently released. But enough being pedantic, let’s instead marvel at this incredible image.
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astronomy, photography, Pluto, science
Australia is bigger than Pluto, are then dwarf continents a thing?
22 April 2025
This, an image comparing Australia with dwarf planet Pluto, was published years ago, but somehow I only saw it for the first time a few days ago. Incredible, isn’t it? Width-ways, going from the east to west coasts, Australia dwarfs Pluto (no pun intended).
But drawing comparisons between dwarf planet Pluto, and the Australian continent, however, makes me nervous. Might such a stark juxtaposition result in Australia being downgraded to dwarf continent standing? In the same way Pluto was demoted from full, to dwarf planet, status in 2006?
Were such a travesty to occur, Australia would have to claim the title of the world’s largest island, an honour presently bestowed upon Greenland. That’s not a new idea though, a rum brand, for one, made the suggestion several decades ago.
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astronomy, Australia, geography, humour, Pluto
No planet has two hundred and seventy plus moons, not even Saturn
15 March 2025
Saturn’s moon count leapt a few days ago, after the International Astronomical Union (IAU) decided to classify an additional one-hundred-and-twenty-eight objects orbiting the ringed planet, as moons. It must be quite the feat of achievement for Saturn to boast it has the most number of satellites, by far, of any other planet in the solar system.
These new moons now mean Saturn is possessed of two-hundred-and-seventy-four satellites. But let’s be serious here. No planet has that many moons, real moons. All of Saturn’s new “moons” are just tiny rocks. They count as moons though, because they have a “proven orbit” around Saturn:
Most of the moons are irregular and tiny, just a few miles across. By comparison, our moon has a diameter of 2,159 miles (3,475 kilometers). But they do have proven orbits around Saturn, which is a key element of official moon candidacy.
Former planet Pluto has a proven orbit around the Sun, yet it is now considered a dwarf planet. This because it no longer meets the IAU’s definition of a planet. We can have different types of planets, it seems, but a moon is always a moon, even it is pet rock size.
But if planetary bodies need to fulfil a certain criteria to be deemed a (real) planet, then a tighter classification of what constitutes a moon, a real moon, is long overdue. If we use our moon, the Moon, as a benchmark, then perhaps Saturn has half a dozen or so “real” moons. The rest would be, as I wrote of Mars’ so-called moons in 2014, merely captured objects.
ETA: on the subject of Saturn, the planet’s fabulous rings will seem to disappear later this month, as far as observers on Earth are concerned. This is because the rings will be edge-on to us, a phenomenon called ring plane crossing, something that happens about every fifteen years.
The rings will become become visible again later in the year though. Who knows, without the rings to distract astronomers on Earth, maybe another batch of moons will be found orbiting Saturn.
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astronomy, Pluto, Saturn, science
These are end days for the Voyager space probes
4 December 2024
It almost seems inconceivable that, one year soon, deep space probes Voyager 1 and 2, will cease to function. At some point their on-board power reserves will be completely drained, rendering the vessels unable to collect data, and send it to mission controllers on Earth. We know their batteries will go flat sooner or later, and what equipment that hasn’t yet failed, will eventually. But by the time that happens, they may have been operational for fifty-years.
Both probes have experienced numerous faults of some sort, which mission controllers have mostly been able to rectify. Despite them being almost a light-day distant. Boosting their supply of power, being able to somehow recharge the batteries though, is unfortunately not a solution that can be effected. Various on-board systems can be shut down, but that only acts to conserve power, not replenish it. It’ll be a strange day, the day we learn we’ll no longer hear from either vessel.
Still, the New Horizons probe, which flew passed Pluto in 2015, is still operating as far as I know, so maybe we’ll continue to hear from at least one of our deep space emissaries, after the lights go off on the Voyager probes.
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astronomy, Pluto, science, technology
The search for the distant Planet Nine continues
27 May 2024
Weird stuff is happening out on the remote boundary of the solar system. Beyond the orbit of Pluto. You name it, it’s going on out there. Irregularities. Anomalies. Clustering of apsidal lines. Perihelia. And — saving the best for last — a surprising prevalence of retrograde Centaurs.
These anomalies include the apparent clustering of apsidal lines of long-period trans-Neptunian object (TNO) orbits, the alignment of their orbital planes, the existence of objects with perihelia extending far beyond Neptune’s gravitational influence, the highly extended distribution of TNO inclinations, and the surprising prevalence of retrograde Centaurs. Collectively, these irregularities hint at the existence of a yet-undiscovered massive planet, tentatively named Planet Nine (P9), whose gravitational influence sculpts the outer reaches of trans-Neptunian space (Batygin et al., 2019).
But this is nothing new. Astronomers have been aware of this activity for some time.
Many postulate this weirdness points to the existence of an — as yet — undiscovered, large-ish planet, out beyond the known planets of the solar system. Some incredible distance out beyond the known planets. Planet Nine, if it exists, is thought to be orbiting the Sun at an approximate distance of twenty times that of Neptune to the Sun.
The gravitational influence of Planet Nine, combined with its extreme distance from the Sun, is enough to interfere with what would otherwise be predictable orbits of the numerous TNO objects, of which Pluto is one.
Planet Nine sort of comes along and displaces — sweeps aside, perhaps — these TNOs. While the presence of a larger planet therefore appears to be the logical explanation for the various irregularities and anomalies witnessed in the outer solar system, scientists are yet to clap eyes the elusive body. Or even calculate its position mathematically, for that matter.
If Planet Nine is found, here’s hoping one of Earth’s space agencies dispatches a probe pronto to go and take a good look at it.
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The solar system has another planet, but where is it hiding?
20 September 2023
Astronomers are convinced the solar system hosts another planet, often dubbed Planet Nine, or Planet X, but are unable to agree on its size and mass, nor its location.
A few years ago speculation was rife a Neptune size body was orbiting the Sun well beyond Pluto, taking between ten to twenty thousand years to make a circuit. While mathematical evidence suggested the existence of the planet, observations turned up nothing.
Now astronomers think a planet similar in size to Earth may be lurking in the far reaches of the solar system, though nowhere as far out as the supposed Neptune size body:
According to planetary scientists Patryk Sofia Lykawka of Kindai University in Japan and Takashi Ito of the National Astronomical Observatory of Japan, this world, frozen and dark so far from the Sun, would be no greater than 3 times the mass of Earth, and no farther than 500 astronomical units from the Sun.
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Pluto, the solar system’s other red… planet?
14 July 2015
NASA’s New Horizons space probe will probably be skimming, mere thousands of kilometres, passed Pluto around about now. That means the photos it sends in the next few days will doubtless be far sharper than the above image of Pluto and Charon, taken from a distance of approximately twenty million kilometres.
While it’s been known for sometime Pluto is reddish-brown in colour, I didn’t realise it was referred to as the solar system’s “other red planet”, with Mars being, I guess, the red planet. While both have reddish hues, their colouring comes about in quite different ways:
What color is Pluto? The answer, revealed in the first maps made from New Horizons data, turns out to be shades of reddish brown. Although this is reminiscent of Mars, the cause is almost certainly very different. On Mars the coloring agent is iron oxide, commonly known as rust. On the dwarf planet Pluto, the reddish color is likely caused by hydrocarbon molecules that are formed when cosmic rays and solar ultraviolet light interact with methane in Pluto’s atmosphere and on its surface.
Also, isn’t referring to Pluto as “other red planet”, with the operative word being planet, likely to start all sorts of arguments?
Originally published Tuesday 14 July 2015.
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astronomy, legacy, Pluto, science
Not every moon is a moon, most are captured objects
9 January 2014
Here’s a 2010 photo, taken by the European Space Agency’s Mars Express probe, of Phobos, one of two… moons orbiting Mars. But that’s not a moon. And nor is Deimos, Mars’ second so-called moon. In reality they’re merely random rocks captured by the Red Planet at some point in the past.
Take a look at Earth’s moon. The Moon. It’s elegant, sizeable, and spherical. The same cannot be said of the rocks orbiting Mars, a couple of unfortunate asteroids that once strayed a tad too close to the fourth planet. Most of the outer planets of the solar system have moons similar in stature to Earth’s satellite, but they also host a bunch of minuscule, oddly shaped rocks, called moons simply because they orbit the planet in question.
It makes me think it is time to consider what really constitutes a moon. If Pluto can no longer be regarded as a planet, why then must every last rock that has been pulled into orbit by a planet, be called a moon? Surely such bodies should adhere — like planets, real planets — to some sort of criteria before being called a moon.
Being pretty much spherical, and of a certain size and mass, could form basic benchmarks, and anything under a certain size should be referred to as a captured object rather than a moon. Sorry Mars, but both your orbiting companions, Phobos and Deimos, are captured objects, not moons.
Originally published on Thursday 9 January 2014.
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astronomy, legacy, Mars, Pluto, science
Pioneers 10 and 11 courses inexplicably varying at Kuiper Belt
15 September 2004
Something weird is happening out on the boundary of our solar system, an area called the Kuiper Belt, where NASA space probes Pioneers 10 and 11 are presently located.
Both deep space probes, launched over thirty years ago, traversed the inner region of the solar system almost exactly according to plan.
Since passing beyond the orbit of Pluto though, events have taken an unexpected turn: both probes appear to be inexplicably deviating from their projected courses.
And no one can work out why. Some scientists think long held ideas on the effects of gravity over extended distances may be need to be re-thought. Others say that both probes may be leaking gases, which is contributing to the change in their trajectories.
This mystery has led to calls for a new deep space mission to see what’s happening out at the Kuiper.
By fitting a Pioneer follow-up probe with new measuring equipment, navigational device and communications gear, it should be possible to discover if the probes are in the grip of a new force of nature.
A new force of nature? Perhaps Star Wars director George Lucas’ far, far, away galaxy may not be all that distant after all…
Originally published Wednesday 15 September 2004.
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astronomy, legacy, Pluto, science