Space Exploration

[ysabetwordsmith]

Surprise! Tiny world with an atmosphere in outer solar system

Astronomers in Japan have just discovered that the tiny world 2002 XV93, orbiting in the icy reaches beyond Neptune, does have a thin atmosphere. That’s despite the fact that this space rock is just some 310 miles (500 km) in diameter. That’s about 7 times smaller than our moon.

The researchers said on May 5, 2026, that they detected the atmosphere when the tiny world passed in front of a star. Using multiple telescopes, they saw that the light from the star gradually faded instead of just suddenly winking. That’s evidence for a thin atmosphere around 2002 XV93.


There are several qualification for "planet" status, including:

* It's large enough for gravity to crush it into a relatively smooth round shape.

* It can hold an atmosphere.

* It's big enough to spot from Earth with low-level equipment.

Comments

[siliconshaman]

Makes sense... it would be an atmosphere of ultra cold gases, probably helium/hydrogen both of which do strange things at low temperatures, also with very little in the way of solar wind it wouldn't strip a thin atmosphere away as fast.

And with a body that small, there's a chance it has atmosphere because of a strong magnetic field instead of gravity alone. Helium IIRC has paramagnetic properties at ultra low temperatures.

IOW, it is very weird, ought not to exist unless there's some very odd physics going on, and is more than worth investigating.

Thoughts

[ysabetwordsmith]

>> Makes sense... it would be an atmosphere of ultra cold gases, probably helium/hydrogen both of which do strange things at low temperatures, also with very little in the way of solar wind it wouldn't strip a thin atmosphere away as fast.<<

Possibly.

>>And with a body that small, there's a chance it has atmosphere because of a strong magnetic field instead of gravity alone. Helium IIRC has paramagnetic properties at ultra low temperatures.<<

Oh, that's interesting. I didn't know about the magnetic option.

I'm leaning towards sublimating ice -- either the thing attracts comets, or has an ice layer of its own. But that's just one option.

>>IOW, it is very weird, ought not to exist unless there's some very odd physics going on, and is more than worth investigating.<<

Yeah, I really want to shower it with robots. :D

Re: Thoughts

[kengr]

Article I read suggested it may still have a "molten"core. Of ice. and the atmosphere is from cryo-volcanoes

Re: Thoughts

[ysabetwordsmith]

Well, there are moons with cyrovolcanoes, so that would make sense. But then why is it still so molten way out there? I'd check for gravitic interactions, because tidal pull can have that effect.