Maybe, maybe not. “Asteroid” and “comet” are terms made up to describe objects in this solar system: “astroids” are inert lumps of rock and metal that primarily have orbits between Mars and Jupiter, “comets” are lumps of rock, metal, and frozen gasses that come into the inner solar system on extremely elliptical orbits with an aphelion far beyond the outer planets. But there isn’t a fundamental dividing line between the two types of objects. You can have comety astroids and asteroidy comets.
There are “asteroids” out past the snow line that would act like comets if brought close to the sun. And there are probably plenty of “dry” rocks tossed into the Oort cloud by the gas giants that wouldn’t be active if brought into the inner solar syestem (and we may actually get them but never see them because they don’t form comas and tails). We get dry asteroids and wet comets in this solar system because of the positions of the gas giants interacting with the small solar system objects. But in solar systems with much closer gas giants (or much hotter stars) they would be tossing out a lot more dry objects.
So for this interstellar object, who knows? It is showing a faint coma and tail now. That may be the most it will or can produce, or it might become highly active. Only time can tell.
Also, the things that spend all of their time relatively close to the Sun might have had a fair amount of water in them originally, but it’s all evaporated by now. Comets only retain their water for a significant amount of time because they only spend a few months per century or millennium close to the Sun, and so there hasn’t been a chance to lose all of it yet. But if this object was ejected from its origin system fairly quickly (as most things that get ejected probably are), then it might still have the moisture that our “asteroids” have lost.
Nitpick: it’s momentum, not velocity. If a comet loses a large amount of velocity by interacting with Jupiter, Jupiter is obviously not going to gain that same amount of velocity and go shooting off from its orbit. It will gain whatever momentum that the comet loses, but since Jupiter is so much more massive, the change in its velocity will be trivial.
There are comets that spend all their time close to the Sun. Comet Encke, for example, has an aphelion of only 4.1 AU, which means it’s well inside Jupiter’s orbit. In fact, there’s 79 known comets with similar orbits, that is, those whose orbits don’t reach Jupiter’s (5.2 AU). They’re called Encke-type comets. However, they haven’t been in those orbits for very long astronomically speaking (perhaps a few thousand years). Since they have periods of around 3 years or so, their ices will completely evaporate fairly soon (astronomically speaking) and, assuming there’s anything left, they’ll become asteroids.
The comet has been estimated to weigh over 33 billion tons. Which is very large indeed.
A new study has attempted to pin down the properties of interstellar comet 3I/Atlas, finding it is “anomalously massive” at around 33 billion tons.
This is not anomalously massive for a comet, though it is a very big one. The team say it seems very large considering the supposed sparsity of other interstellar material that has entered the solar system.
Not even the biggest coment currently visible. As per the article, C/2014 UN271 is around 500 trillion tons. (Hale Bopp is estimated at around 190 trillion tons.)
The observations show that the comet is leaking water at a fast rate even when it should seem too far away from the Sun to do so.
“What makes 3I/ATLAS remarkable is where this water activity occurs. The Swift observations detected OH when the comet was nearly three times farther from the Sun than Earth—well beyond the region where water ice on a comet’s surface can easily sublimate—and measured a water-loss rate of about 40 kilograms per second—roughly the output of a fire hose running at full blast. At those distances, most solar-system comets remain quiet.”
I always thought of the planet killer that might someday do us in as originating from the asteroid belt or the Oort Cloud, but imagine if we end up being done in by something from another star system God knows how many light years away. Imagine how astronomically (literally) small the odds are for that to happen! Imagine how many eons that object would travel through the depths and darkness of interstellar space before its fateful rendezvous with our hapless planet!
The odds of Earth being hit by an interstellar object are considered
infinitesimal, far lower than the risk posed by objects that originate within our own solar system. Interstellar objects are extremely rare visitors to our celestial neighborhood and pass through at very high speeds, making an impact highly improbable.