A new study examining the properties of one of our solar system’s dwarf planets suggests it may have a “fluffy” composition, closer to “soft cheese” than a hard ball of stone. There was found.
Eris lurks at the edge of our solar system, taking 557 years to orbit the sun, but it has remained largely a mystery to astronomers since its discovery nearly 20 years ago.
But a collaboration between two researchers, including one of Eris’ original discoverers, has shed new light on the object’s inner workings.
The results of several months of modeling have been published in a peer-reviewed journal scientific progress In mid-November, researchers described a dwarf planet characterized by a constantly changing, slimy icy upper layer.
Francis Nimmo, a researcher at the University of California, Santa Cruz, explains: in a press release Last week, he described Ellis’ surface consistency as “soft cheese or something similar” rather than a completely hard object.
“It tends to flow a little bit,” he said.
About six months ago, while at Caltech, Nimmo realized that new data unearthed by Michael Brown, one of Eris’ discoverers, could shed new light on how Eris functions.
Key to the model they created together was a detail Nemo didn’t previously know: the mass of Eris’ single moon Dysnomia.
Dr. Brown used measurements from the Atacama Large Millimeter Telescope (ALMA) in Chile to discover the upper limit of Dysnomia’s mass, which means that the two knew the maximum gravitational force that could be exerted on Eris. means.
Eris and Dysnomia are tidally locked. When Dysnomia orbits, it always faces the same side towards Eris.
“This happens because the large planet is rotated by the ebb and flow of the tides caused by the small moon,” Nimmo said in a statement. “The larger the moon, the faster the planet spins.”
With Brown’s data narrowing down the moon’s size, they were able to analyze the orbital interactions between Eris and Dysnomia and get a better idea of what’s going on inside Eris.
Models suggest that Eris likely has a core of hot rock surrounded by layers of flowing ice.
“Rocks contain radioactive elements that generate heat, and that heat has to get out somehow,” Nimmo explained. “So as the heat escapes, it promotes this slow agitation in the ice.”
This gives Eris a fluid yet non-fluid surface composition, like a snowball that never melts but is always in a molten state.
Inside a dwarf planet in our solar system
If you were born before the ’90s, you probably grew up imagining that there were nine planets in our solar system, the ninth being Pluto, the smallest and farthest from the sun.
However, Pluto is currently known to be one of the five dwarf planets that inhabit our solar system, ranking with Eris, Ceres, Makemake, and Haumea.
A dwarf planet is a celestial body that does not fully meet the criteria to be considered a planet, but is close enough to be considered an asteroid. Dwarf planets do not have enough gravity to dominate their own region of space, but they do have enough gravity to be spherical or close to spherical.
Eris was first discovered in 2005, and the Canadian Space Agency says the discovery may have been a harbinger of Pluto’s demoted death a year later. This is because although Eris appears slightly smaller than Pluto in terms of size, it actually contains over 25 percent more matter within it, making it the most gravity-heavy dwarf planet in the solar system. .
Fittingly, with Pluto’s celestial importance down a notch, Eris was named after the Greek goddess of discord.
Eris sparked much scientific debate when it was discovered, but because it orbits beyond the orbit of Neptune, far from the Sun, its properties remained largely unexplored for many years. Until now, astronomers thought it had a rocky surface, similar to Pluto.
This new research not only helps flesh out the villains of this dramatic tale of once planetary collapse, but also furthers our overall understanding of dwarf planets.
The researchers hope that measuring the size of dysnomia more specifically will help them refine their models in the future.
“If Dysnomia is smaller, Eris is squishier,” Nimmo said.