Pluto’s Almost Twin Dwarf Planet Eris Behaves Less Like Solid Rocky World, More Like Soft Cheese

Eris, which is dubbed Pluto's almost twin dwarf planet, behaved in a different way than expected. Researchers were surprised that it appeared to be squishy and not solid.

Eris Is Squishy, Unlike Pluto

Astronomers discovered a tiny, cold planet called Eris over 18 years ago, billions of kilometers beyond Neptune. However, Eris has not received any robotic visitors, in contrast to its dwarf planet neighbor Pluto, which New Horizons revealed to be a vibrant, dynamic world during its visit in 2015.

In fact, it is so far from Earth that in observations, it appears to be only one light pixel. Overall, relatively little is known regarding the activities on Eris.

However, because of its proximity to the solar system's boundary, Eris is known to have an atmosphere that snows and freezes into the planet's surface below. Compared to Earth, it is approximately 68 times further from the sun.

Furthermore, newer models have unveiled further information on Eris based on data from a variety of radio telescopes in Chile. It appears as though heat from the dwarf planet's formation is seeping out and gradually bending its frozen surface.

Eris is behaving "more like a soft cheese or something like that" as a result of the process, according to a statement from Francis Nimmo, co-author of the paper and professor at the University of California, Santa Cruz. "It has a tendency to flow a bit."

The mass of Eris' tiny moon Dysnomia was determined by Nimmo and his colleague Mike Brown, a Caltech astronomer best recognized for being the one who killed Pluto and led the 2005 discovery of Eris. Since Eris and its satellite face each other in the same direction, they are mutually tidally locked. The reason for this, according to scientists, is that Eris's tiny moon "raises" the tides, which causes the dwarf planet to spin down over 4.5 billion years.

According to the latest research, Eris most likely has an icy shell convecting around a rocky core. Heat is produced by the radioactive elements found in the rock. The heat then needs to be released in some way. As a result, the ice is slowly churning as the heat escapes, according to Nimmo.

What Is Eris?

Eris is larger than Pluto and both are classified as dwarf planets. On Jan. 5, 2005, Eris was found using information gathered on Oct. 21, 2003, during a survey of the outer solar system conducted by Mike Brown, a planetary astronomy professor at the California Institute of Technology, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University at Palomar Observatory.

Eris is named after the ancient Greek goddess of discord and strife. It was originally classified as 2003 UB313 and given the moniker "Xena" by its discovery team. Eris is still at the center of scientific controversy on what constitutes a planet. Therefore, the name makes sense.

Eris' radius is around one-fifth that of Earth, measuring roughly 722 miles (1,163 kilometers). Similar to Pluto, Eris is somewhat smaller than the Moon.

Eris would be roughly the size of a popcorn kernel if the Earth were the size of a nickel. It appears improbable that life could survive on Eris, given its extremely frigid surface.

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