This is amazing. It never ceases to amaze how much complex behaviour can emerge from gravitation. After black holes, neutron stars, gravitational waves, solar systems, this is yet another example of a structure that arises from gravitation alone (granted, many other principles of physics are needed for this to happen - for example conservatin of angular momentum). What else will we discover?

Honestly, this is a bit click baity. It's two asteroids orbiting each other if anyone is wondering.

Yes, but they're also sublimating ice, so they have a coma and tail. Thus they're also classified as a comet.

As the article goes on to say, they couldn't have lasted all that long like this, so one theory is they used to be one asteroid that broke in two, exposing the ice that is now forming the tail.

Not sure I understand. How much H2O/liquid/ice is inside an asteroid? Is the core made of liquid?

In short, it simply depends on an asteroid. This one had ice, another might have not.

Yes. Imagine a dirty snowball. As ice on the outside burns away the thing shrinks until the outer layer is more rock and less snow. So you have a layer of dirt/rock layer above a "core" that has more ice. But he ice inside is still being heated. So ports, like little volcanoes, form in the outer layer to let steam out from the core. Thats where the jets of water/ice come from. But it all starts with the dirty snowball.

> Hubble discovers first known binary asteroid also classified as a comet

Unless the title has changed in the last 2 hours, or that it's not the first occurrence of such, the title is an accurate depiction on the phenomenon described in the article.

The original title was the one from the article: "Hubble discovers a unique type of object in the Solar System"

Gotcha, sad to see the article title is indeed the one you mentioned, even though is not totally inaccurate.

The image isn't clear enough to proclaim such things.

It appears to be, to the subject matter experts.

You can be wrong at any level if you start extrapolating details.