Stars and gas giants are pretty darn big, but they’re made out of gas, not rock. Their cores may be as dense as Newtonium, but they’re not “terrestrial.”
What’s the biggest chunk of solid, contiguous matter known to astronomers? It couldn’t possibly be the Earth, but offhand I can’t think of any larger chunks of solid. Can anyone out there?
Oh the post isn’t that bad. The question seems to be “What is the largest known solid object in the universe?” Notice not the most massive since a solar mass blackhole could be 6km across.
I’d say one of the newer hot Jupiters. They’ve likely lost all of their gas envelops.
Terrestrial=Of or relating to the earth or its inhabitants. (dictionary.com) Your title is “what’s the biggest object on earth” but your question is what is the biggest known solid object in the universe"
The OP seems 100% coherent to me. What’s the problem?
The biggest chunks of solid matter definitively known to exist would be neutron stars, which are no longer balls of gas. So whatever the biggest known neutron star is is the answer.
“Terrestrial” doesn’t just mean “on Earth.” We have two kinds of planets in our Solar System: Terrestrial (Mercury, Venus, Earth, Mars) and Gas Giants (Saturn, Jupiter, Uranus, Neptune). Pluto may or may not be a third kind of planet, but it’s closer in type to Terrestrial than to gas giant.
So I’m asking about Terrestrial (rocky, solid, not made primarily out of gas) objects in space. Are there any known to be larger than Earth?
Given that the composition and solidity of the hot jupiters are still somewhat unclear, I would say of the objects KNOWN to be solid, or at least to have a thick solid crust and thin atmosphere… (since even earth has a ‘gaseous layer’ about it and liquids at various levels, including the partial ocean layer and the iron core…)
The earth has it, followed closely by Venus.
This is largely just because we don’t know that much about the universe outside our solar system, except for things out there that are very bright, and things very bright tend to have too much energy to be solid. We happen to be the largest rocky body in our solar system.
There are numerous types of astronomical object. But “Terrestrial” as an adjective means, roughly, having a solid crust including both rock and regolith/soil, with an atmosphere unless circumstances dictate otherwise. It’s opposed to “Jovian” – characterized by Jupiter and Uranus, and having the sorts of characteristics that they do.
The largest definitely known Terrestrial planet is the Earth, with Venus running a close second. I believe one of the extrasolar planets known solely from perturbances in stellar motion is thought to be either a very small Jovian or a very large Terrestrial planet.
Various works of SF including Hal Clement’s Mission of Gravity and Poul Anderson’s A Stone in Heaven postulate circumstances in which Terrestrial planets much larger and with much higher gravity than Earth('s) might exist, and what conditions on them might be like.
(Note, by the way, that there is no clear defining line between Jovian planet and small star – the speculative category of “brown dwarfs” AKA “Superjovians” bridges the gap, though AFAIK none are known.
“Terrestrial planet” does mean “earth-like planet”. Although I was a bit confused by the title too - when I hear “terrestrial object” I take that to mean something down here on earth, as opposed to something up there in space.
Anyway… While neutron stars are far more massive than the earth, they are smaller. So that’s not the answer. While we have found a number of extrasolar planets, I don’t think we know which ones are gaseous and which are solid. So I belive the largest object we know to be solid is the planet earth. Or to be specific, its crust.
The topic of neutron stars keeps coming up. Do we know that they are “solid” as defined by the OP? If so, and we have determined that they can be bigger than earth, I’d go for them. However, I’d think they are gaseous, just VERY dense, keeping in the definition of a star as I know it.
Neutron stars are in fact more solid than defined by the OP - the earth is made up of atoms (forgive me for covering the basics ), whereas a neutron star is made up solely of neutrons.
The neutrons group together to form a massive (but not necessarily large) “star” which is essentially the nucleus of an atom on a much grander scale. As I’m sure you’ll recall from school, the atoms that make up the earth are mainly empty space, with a tiny nucleus in the centre.
Neutron stars don’t have the empty space and as such are very, very dense (A book called “The Science of Discworld” quotes a figure of the order of 100 million elephants in a nutshell).
Because of this very high density, however, even the largest ones are only a few kilometers in diameter (to my “layman with an interest” knowledge), and therefore not larger than the earth.
Neutron stars are definitely more massive and denser than the Earth, but they are not solid. Neutronium is a superfluid, so if you’re going to classify neutron stars in a simplistic scheme of solid, liquid, gas, they’d probably be closest to liquid (though not quite: The equation of state of a neutron star doesn’t really correspond to liquid or gas). White dwarfs and black dwarfs (white dwarfs which have gotten old and therefore cold), however, are probably solid (or a reasonable approximation thereof). They’re about the same diameter as Earth, but much more massive. I don’t know offhand how big the largest known white dwarf is, or if it’s larger than the Earth.
If the question is: What’s the largest known hunk of rock, the answer is the Earth. Neutron Stars and White Dwarfs probably aren’t what he’s looking for.
I believe this is no longer “speculative”. This recent article on space.com concerns a photo of what may be a planet circling a brown dwarf. Naturally, a photo of an extrasolar planet would be a big deal. The brown dwarf in that same photo is mentioned in an off-hand manner, implying such things are quite common.
Yeah, that’s pretty much it. I was wondering if there were any known Earth-type planet or other heavenly body (Rock, dirt, crust, something that could be walked on or terraformed, should circumstances permit) larger than Earth. It just strikes me as odd that we’re the biggest.
See above: we’re really not very good yet at seeing big lumps of rock floating in space, except really close by and within range for our sun to illuminate them. Given that close range at which we can see such objects, it’s not really that odd that we’re sitting on the biggest one.