Comet Births and Neptune's Secrets

This is Space Time, Series 29, Episode 109, for broadcast on September the 11th, 2026. Coming up on Space Time, witnessing the birth of a comet, new mysteries about the moons of the planet Neptune, and NASA's Roman Space Telescope blasts off bound for orbit beyond the moon. All that and more coming up on Space Time. Welcome to Space Time. With Stuart Gary. More than 5 billion kilometers from Earth, an ancient icy object is slowly awakening. Astronomers are witnessing a distant frozen world known as a centaur in the process of transforming into an active comet. The discovery, reported in the Planetary Science Journal, is offering a rare look at how some comets are formed. Centaurs are small icy objects that typically orbit between Jupiter and Neptune in the outer solar system. They're thought to have originated beyond Neptune in the Kuiper Belt, a ring of frozen worlds circling the Sun. But as this particular centaur, catalogued as 450 P. leoneos, drifts slowly inwards, it's begun releasing gas and dust. And that's a behavior normally associated with comets. The study's lead author, Charles Shambo, from the University of Central Florida, says centaurs are scientifically important because they're thought to be transitional objects that originated much further out in the solar system and are slowly evolving towards becoming Jupiter family comets. He says they provide a way to study relatively primitive material from the outer solar system while it's still only beginning to respond to stronger solar heating. Shambo and colleagues have been monitoring this distant object using the Webb Space Telescope and the Gemini North Observatory in Hawaii. They've detected carbon dioxide gas, icy dust and signs of recent thermal activity surrounding the centaur. The authors believe that 450P Leonis began waking up following a close gravitational encounter with Saturn in 1992, which significantly altered its orbit. they found the interaction moved the centaur inwards from a more distant trajectory, bringing its perihelion, that's the point of its orbit closest to the Sun, closer to Jupiter. The authors observed the gradual formation of a faint coma, that's a cloud of gas and dust surrounding the nucleus commonly associated with cometary activity. Continued monitoring between 2019 and 2024 showed the coma had become increasingly visible as the object's distance from the Sun decreased. Chembo says this increased solar heating can warm the surface and subsurface layers of the nucleus. And as these layers heat up, volatile ices or trapped gases can be released, which can drag away dust from the surface, producing a coma. One of the study's most significant discoveries came from the detection of carbon dioxide gas surrounding 450 P. leonis at a distance where ordinary water ice would typically vaporize. They found strong evidence of carbon dioxide emissions, but no signs of water vapor or carbon monoxide, suggesting the carbon dioxide is likely driving the centaur's activity. The observations also revealed icy dust grains within the coma, including possible signs of crystalline water ice, material that may well preserve evidence of the object's thermal evolution as it warms in its new orbit. Schember says the carbon dioxide detection is important because it directly identifies one of the gases likely driving the activity. At its current distance from the Sun, the nucleus is too cold for normal water ice sublimation to be the main activity source. So detecting carbon dioxide gives astronomers an important clue about what's powering the coma. The possible crystalline water ice is also interesting because it suggests that some of the ice in the comas experienced heating or physical processing, rather than remaining completely unchanged since formation. Only a relatively small fraction of known centaurs show visible activity, making objects like 450 Peleotis especially valuable for studying how primitive icy bodies evolve over time. The research suggests the object's recent activity may be linked to warming beneath its surface. As buried amorphous ice, an irregular form of ice that traps gases inside its porous structure, warms and transforms into crystalline ice, it releases carbon dioxide gas into space, carrying dust with it and creating the coma. This process may explain how 450P Leonis became active after its orbital change and it began receiving more sunlight. The released gas can escape through the porous nucleus and then lift dust grains into the surrounding coma. The findings are providing scientists with a better understanding of how distant icy bodies gradually evolve into active comets, which periodically visit the inner solar system, coming closer to the Earth. This is Space Time. Still to come, new mysteries about the moons of Neptune, and NASA's Roman Space Telescope blasts off bound for orbit beyond the moon. All that and more still to come on Space Time. While we're dealing with the outer solar system, a new study has revealed that three of Neptune's inner moons may actually be the shattered remains of ancient icy worlds. The findings reported in the journal Science Advances show the composition of the Neptunian moons Larissa, Galatea and Proteus are unique among outer solar system bodies. In 1989, the Voyager 2 mission discovered six new moons orbiting Neptune, including five tiny ones that orbit just inside the planet's main rings. Because of their small sizes and locations, these satellites have been difficult to study from Earth until now. But using NASA's Webb Space Telescope, scientists have now been able to observe Neptune's rings and some of these tiny moons in greater detail. The new study suggests there may have been an original moon system that was demolished when Triton, Neptune's largest moon, was likely captured by the planet's gravity after it formed elsewhere in the solar system, most likely as a Kuiper Belt object similar to Pluto or Charon. The study's authors believe remnants left behind from this cosmic collision then created together to form the inner moons we see today. The study's lead author, Rayleigh Davis from Caltech, says that if Neptune once had a system of moons that looked something like what we see around Uranus today, it would have been completely destroyed as Triton got captured. Davis says something catastrophic happened at Neptune, which completely destroyed its original satellites, and what's there now are the fingerprints left behind by that process. Neptune's a curious planet, as it's the only one in the solar system that lacks a typical moon system of large, ordered satellites, meaning its evolutionary pathway might also be unique. In fact, another recent study suggests Neptune's moon, Nereid, may be the sole surviving intact member of its original moon family. To look for more clues that could help reconstruct Neptune's history, Davis and colleagues examined the planet's inner moons. Until recently, no spectroscopic data existed for these moons. Spectrographs, such as the near-infrared instrument on Webb, split light into its many wavelengths to obtain information about the chemical makeup of astronomical targets, thereby enabling scientists to identify the molecules present. And the authors were shocked to find magnesium-rich phyllosilicates in the spectra of Larissa, Galatea, and the Neptunian rings. You see, these mineral clays only form in the presence of liquid water, and liquid water has never been detected anywhere in the outer solar system beyond Jupiter before. And yet no water ice is indicated by the spectra of any of the three moons studied, or the rings for that matter. That means they must have come from objects that were much bigger than Neptune's small inner ring moons. Davis says everything that far out is really icy. So the phyllosilicates must have come from something deep inside something that was big enough to generate enough heat that it melted its original water ice. and the most likely place would have been an original system of icy moons, although it's a bit of a mystery as to where the ice may have gone. And don't forget, these phyllosilicates weren't present on Proteus, the largest of the small moons being investigated. That suggests it may have accreted from a different region of the debris disk, or alternatively, undergone subsequent heating that destroyed any clay minerals present. The authors also found that each of the three moons have a collection of hydrated minerals that they're unable to identify. Davis says it means they're seeing something that doesn't look like anything they've ever seen before, and it doesn't match anything in the spectral library. She's assuming it's some form of hydrated rock, but there's still a lot of mystery. While the authors favor this primordial satellite destruction hypothesis, they point out that an alternative explanation involving tidal shredding can't be ruled out. Tidal shredding would involve a large differentiated Kuiper belt object, similar in size to say Pluto, that passed too close to Neptune and was torn apart by the planet's gravity. Either way, Davis and colleagues are seeing something on these moons that had to have come from deep inside something much larger. It's a fascinating discovery. This is space time. Still to come... NASA's Roman Space Telescope blasts off bound for orbit beyond the moon. And later in the science report, a new study has found a link between flavoured chemicals in some vapes and problems with pregnancy. All that and more still to come on Space Time. NASA's next great flagship cosmic observatory, the Nancy Grace Roman Space Telescope, has successfully launched into space, bound for orbit on the dark side of the Earth beyond the Moon. The spectacular liftoff took place aboard a SpaceX Falcon Heavy rocket from Pad 39A at the Kennedy Space Center at the Cape Canaveral Space Force Base in Florida. T-minus 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, ignition and liftoff. Go Falcon Heavy and go Roman Space Telescope. And liftoff of NASA's Roman Space Telescope on a mission to revolutionize our understanding of the universe. All M1D chamber pressures are nominal. Falcon Heavy has cleared the tower and is on its. Way to space. After separating from the core stage, the rocket's side boosters safely return to the launch site for recovery and refurbishment. Side booster separation confirmed. Stage separation. PY boost back startup. And there's confirmation of the boost back startup on those two side core boosters. So at this point, both Falcon Heavy side boosters are performing their boost back burns, which is the first of three burns each side booster will undergo on the way back to Cape Canaveral Space Force Station. Now, the primary objective of the boost back burn is to quickly reorient the side boosters onto the required return trajectories. and this is required in the event of a return to a launch site as opposed to a drone ship ocean recovery. And today they're headed towards landing zones 2 and 40 in Florida. Now, meanwhile, in the center core, the nine M1D engines are continuing to power Falcon Heavy on its nominal trajectory. They're set to burn for about another 12 seconds or so, and then they'll throttle down, and we'll have our MECO, our main engine, cut off of that, and then we'll have stage separation of this center core and the second stage shortly thereafter. Main trip. Main core and second stage separate from one another, and we just heard that call out for second engine startup. Bearing separation confirmed. All vehicles are following nominal trajectories. Roman is now on a three-month, 1.5 million kilometre journey to the Lagrangian L2 position, a sort of gravitational well where it can maintain position relative to the Earth without expending a great deal of fuel. Once in position, Roman will begin its initial five-year mission to reveal some of the universe's darkest secrets, including new clues about the mysteries of dark matter and dark energy. Unlike the Hubble and Webb Space Telescopes, which focus on individual objects in the sky, Roman will capture whole cosmic ecosystems, discovering things CITES never even knew existed. Seven minutes after launch, mission control teams at NASA's Goddard Space Flight Center in Greenbelt, Maryland, began receiving telemetry data from the telescope. Nominal orbit insertion. The Falcon Heavy rocket performed as expected, separating from the observatory 31 minutes into the flight. A few hours later, the observatory's solar panels and lower instrument sunshade were deployed, followed by its high-gain antenna and visor-like deployable aperture cover. Mission managers then initiated the first of two mid-course corrections, and the coronagraph instrument was also powered on. This instrument will demonstrate the sorts of technology that future missions like the Habitable Worlds Observatory can use to image Earth-like planets. Roman's coronagraph will take a giant step in that direction by snapping pictures of Jupiter-like planets. Next on the list, Roman's primary wide-field instrument will activate. This 300-megapixel infrared camera has 18 4K detectors, each about the size of a cracker. These detectors will collect photons that will be decoded into crisp cosmic panoramas. Throughout the rest of Roman's three-month commissioning period, scientists will run the instruments through a series of calibrations and tests. NASA anticipates releasing Roman's first images early next year. This report from NASA TV. 16 years ago. The science community asked for an infrared survey telescope. And for the last 10 years, the best in the world have been building it. The pieces have come from all over. Small firms across the United States, aerospace industry leaders, research centers like JPL. They took shape and joined systems built at NASA's Goddard Space Flight Center, one of the few facilities in the world capable of handling a project of this magnitude. Here, the team assembled those pieces. The spacecraft bus, holding everything the observatory needs to thrive in space. The high-gain antenna system, communicating with Earth over a million miles away. The coronagraph, performing magic with physics to see distant worlds. The wide-field instrument, scanning the sky with a massive field of view. and the primary mirror assembly, the singular light-catching eye. They were joined with protective layers that shield them from the intense glare of the sun and generate all the power the observatory will ever need. Fully assembled, the observatory was subjected to another battery of tests and then prepared for careful transport to the Kennedy Space Center. The final work at Kennedy is done and the observatory is complete. This is Space Time. And time now to take another brief look at some of the other stories making use in science this week with a science report. Scientists have found a link between flavor chemicals in some vapes and pregnancy problems. A report in the journal Human Reproduction claims the chemical compound vanillin, the primary organic ingredient responsible for the characteristic smell and taste of vanilla in e-cigarettes, could be disrupting the normal development of embryos in pregnant women who vape. The authors believe vanillin might affect embryos through a receptor called TRPV4. human embryonic stem cells exposed to different concentrations of vanillin in lab tests, as well as an antibody that stops vanillin from binding to TRPV4 receptors, and various combinations of the two, found the TRPV4 channel was used by vanillin to adversely impact the cells, with high concentrations tending to kill them and lower concentrations causing the cells to lose their ability to develop into any other type of cell. A new study has confirmed that flight attendants and pilots have the highest risk of death from radiation-related cancers. The findings, reported in the Journal of the American Medical Association, looked at oncology outcomes in over 500 occupations. They found that airline flight crew had an even higher risk of cancer than nuclear technologists. The authors say that pilots and flight attendants accrue an estimated 3 to 6 millisieverts per year of cosmic radiation, roughly the equivalent to the radiation from 30 to 60 standard chest X-rays, and far greater than the 0.4 millisieverts you'd get from taking 10 cross-country round-trip flights a year. A new study has found that a growing plant disease spreading across parts of Western Australia is linked to a habitat loss and less digging activity by native animals such as the southern brown bandicoot. The new findings, reported in the journal Austral Ecology, shows that Vontarthora dieback is connected to a reduction in the habitat quality and digging activity of southern brown bandicoots in Western Australia's priceless Jarrah forests. The authors found that compared with healthy forests, dieback-affected areas had 46% less low scrub cover, 45% fewer habitable grass trees, and 40% more bare ground. They also found that bandicoot digging activity was 33% lower in dieback-infested areas. Scientists claim they're working on a tent that can supply its own electricity. A report in the journal Matters claims the new tent harnesses energy from the environment around it, and it could one day provide a more livable environment for people without homes. The tent uses a phenomenon called magnetoelasticity to convert movement in the tent material caused by outside influences, including human activity, wind and rain, into energy. The authors say the process can harness enough energy to power small electronic devices, which could allow people living off-grid or in tents as a form of temporary shelter to have a higher quality of life without relying on external power sources. Britain's Sun newspaper has been trying to push a ghost story that would be more at home in a B-class movie. The Sun claims it's the real thing, but as the sceptic's Tim Mendham points out, hyperbole takes it all just a step, or should there be a rather giant leap, Too far. This is a story from a recognised journal of note, The Sun, in the UK, which strikes me as apocryphal. This is about the most violent poltergeist ever seen. The story has children being choked and branded, possessions being thrown around the room. I mean large possessions, furniture, chairs, big pots, etc. Mad monks, flying eggs, blood-curdling screams and push chairs being launched down stairs. You name it, this particular story has it. And the weirdest thing is that there are people who are in these houses where these things are happening. Horrible things, day after day after day, and they stay there. You think a priest comes in to do this, then the priest tells them to get out, you know, exorcist style. Although this original story apparently happened in the mid-60s, so before the exorcist. But so many things happening. A place in Yorkshire called Pontefract, the town, and it's a fair with a couple of kids being harassed by this extremely violent hands-on ghost most ghosts don't do they like to knock things over okay but What is it with ghosts? They either are ephemeral things that just go, ooh, wandering around through the walls, et cetera, or they push little objects around like a petulant child. Well, this one is actually grabbing people, branding them, pushing them up and down stairs, knocking things over, trying to attack them. And this family who were there sort of apparently just put up with it for ages. And I sometimes wonder if this particular story was actually made up. I don't know. I don't know enough about it. Amityville Horror was made up. Yeah. What was the other one, the famous one in the UK where the two daughters were voices and all sorts of stuff? It was obviously fake. They actually made a play out of it in various TV programs. Yeah, this sounds like it's just too much of what this person is doing. It's just incident after incident after incident after incident after incident. And the son is treating it as a real story. The son is treating it as a real... Well, it's an urban story that's been going around. How much truth, if any, is in it, I don't know. This one just sounds so extreme. You wouldn't last a day in a place where all these things were happening to you all the time, being branded with a crucifix and dragged and throttled, choked, dragged up the stairs, dragged down the stairs, things being thrown at you all the time, all sorts of things happening. I don't know. It sounds a bit exaggerated to me. Perhaps I'm an old cynic. I don't know. Look, I have things smashed at my place all the time. It's usually the cat, but. Well, I've got things too, but it's not with my wife. We won't go there. No, she's always throwing things at me. That's the Skeptic's Tendendum, and this is Space Time. 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