Astronomers report thin atmosphere on tiny Kuiper Belt object beyond Pluto

A new study suggests that a tiny, icy world beyond Pluto harbors a thin, delicate atmosphere that may have been created by volcanic eruptions or a comet strike. ...Keep on reading: Astronomers spot an atmosphere around a world beyond Pluto

PlutoEveryone’s favourite demoted planet, Pluto, may be shielding a mystery that’s baffled scientists. An icy body beyond the dwarf planet seems to have an atmosphere that shouldn’t be there, according to a paper published in Nature Astronomy.The object should be too small to have an atmosphereAt just 500km across, the object, catchily named (612533) 2002 XV93, ought to be too tiny to have any atmosphere at all. That’s partly why little planet Pluto was believed to be the only object in our solar system that had an atmosphere beyond Neptune. But researchers hink they’ve found a “refractive signature, indicating a thin atmosphere” from the even tinier icy mass. And they do mean “thin”. Some reports suggest the potential atmosphere could be 50-100 times thinner than Pluto’s own, already very weak, atmosphere, and 5-10 million times thinner than ours here on Earth.Nonetheless, the minor “plutino” planet seemed to affect how a distant star looked while it occulted (temporarily appeared to cover) it.Rather than cleanly appearing, being hidden, and then reappearing in a kind of “blink” or “wink” illusion, the star appeared to fade slowly as it approached and left the cover of the plutino. That usually only happens when a plant has an atmosphere, as the gases change how the light is filtered.“This discovery suggests that the traditional idea that global dense atmospheres form only around larger planets must be revised,” the paper reads.However, planetary scientist Alan Stern told the Associated Press that while “The implications are profound if verified,” the “amazing development... sorely needs independent verification”. That could involve confirmation by, e.g., NASA’s Webb Space Telescope. Scientists can’t say for sure why the atmosphere might be there The researchers put forward two theories, though Space.com pointed out that both may have flaws.The first suggests that another body, like a comet, might have impacted the plutino. But that’d be a stroke of luck on the researchers’ part: the gases from collisions like these fade over time, meaning we would have had to have caught it relatively soon after the impact. That’s why, study author Ko Arimatsu told AP, the researchers plan to monitor the site. “If the atmosphere fades over the next several years, that would support an impact origin.” Another theory? Ice volcanoes, which release sublimated gas through cryovolcanic activity. But the cause of this proposed activity is completely unknown.“If [the atmosphere] persists, or varies seasonally, that would point more toward ongoing internal gas supply,” Arimatsu said.Related...A 'Potentially Habitable' New Planet Has Been FoundResearchers Find New Planet Larger Than Jupiter Through Rare Einstein-Predicted MethodNASA May Have Spotted Potential 'Signs Of Life' On Planet Outside Our Solar System

Astronomers are puzzling over another oddball on the edge of the solar system: This time, it's an icy object less than a quarter of Pluto's size with a thin atmosphere – a layer of gas that's not typically found around objects so small.

Observations suggest there's a small, icy object with an atmosphere beyond Pluto, challenging assumptions about which bodies can sustain atmospheres.

A new tiny ice world has been discovered beyond Pluto surrounded by a thin atmosphere, scientists revealed.

"The Associated Press is reporting on a new study in Nature Astronomy suggesting that a tiny, icy world beyond Pluto harbors a thin, delicate atmosphere that may have been created by volcanic eruptions or a comet strike," writes longtime Slashdot reader fahrbot-bot. From the report: Just 300 miles (500 kilometers) or so across, this mini Pluto is thought to be the solar system's smallest object yet with a clearly detected global atmosphere bound by gravity, said lead researcher Ko Arimatsu of the National Astronomical Observatory of Japan. This so-called minor planet -- formally known as (612533) 2002 XV93 -- is considered a plutino, circling the sun twice in the time it takes Neptune to complete three solar orbits. At the time of the study, it was more than 3.4 billion miles (5.5 billion kilometers) away, farther than even Pluto, the only other object in the Kuiper Belt with an observed atmosphere. This cosmic iceball's atmosphere is believed to be 5 million to 10 million times thinner than Earth's protective atmosphere, according to the the study [...]. It's 50 to 100 times thinner than even Pluto's tenuous atmosphere. The likeliest atmospheric chemicals are methane, nitrogen or carbon monoxide, any of which could reproduce the observed dimming as the object passed before the star, according to Arimatsu. Further observations, especially by NASA's Webb Space Telescope, could verify the makeup of the atmosphere, according to Arimatsu. Read more of this story at Slashdot.