Dirt on other planets

[Cadet_BNSF]

So I got a new Mars globe, and as I was marveling at the beauty of Mars, I had a question come to me, since dirt on Earth can also be called earth, would dirt on Mars be called mars or earth?

[UmbralRaptor]

Regolith

[Bill Phil]

Only if it's soil.

[kerbiloid]

But there can't be soil without plants.

Though, probably a clay also is a dirt, and it's inorganic.

[Green Baron]

That "dirt" or in your language (not necessarily everywhere on Earth) "earth" is the product of a combination of biosphere activity as well as weathering in different forms, physical/mechanical, chemical, by gravity, etc. pp.

These processes don't exist in that form on other planets and right now it is not quite clear if the principle of uniformity that serves more or less well on earth Earth can be applied to ET stuff as well. It may be safe to assume that this can be doubted.

But "dirt" and "earth" are colloquial terms, in principle you can use them freely.

 

Edit: soil science (pedology) is an own branch in geosciences, if you are interested ....

Edited July 20, 2017 by Green Baron

[Green Baron]

2 hours ago, kerbiloid said:

But there can't be soil without plants.

Yes. And especially microorganisms.

2 hours ago, kerbiloid said:

Though, probably a clay also is a dirt, and it's inorganic.

A clay is a weathering product at the distal end of weathering processes. Yes, a pure clay would be inorganic. But in reality, if it is somewhere in a soil horizon, it is inhabited :-)

[kerbiloid]

Yes,
Soil = rotten flesh + inorganic rubbish.

No flesh - no soil.

[NSEP]

Its called Regolith, on lifeless planets and moons, asteroids. The same way there are no Biomes on other bodies without life, KSP is worng with that, its more something like Geomes, i think?

[kerbiloid]

Regolith is not a dirt, it's a dust or a sand.

Depends on definition of "dirt" or "mud".

Are boots covered with soil dirty? Muddy?
Are boots covered with clay dirty? Muddy?
Are boots covered with dust dirty? Muddy? Just dusty?

If treat any pulp-alike pollution as dirt, then wet regolith would be a dirt. Dry regolith is probably just a dust.

If "dirt"/"mud" means only pollution made with Earth-like soil, then no. 
Originally there was no "soil" on Earth, only eroded rock (i.e. regolith), or residual soil.

Real soil has appeared when microorganisms had appeared, spread around and began to die.
Their organics mixed with regolith is what we call soil.

(This was a key moment, because allowed plants to cover the ground and prevent the landscape erosion)

Upd.
Btw an offtop about Mars ground
http://onlinelibrary.wiley.com/doi/10.1002/2017GL074002/abstract;jsessionid=EF0C893EE4D8AA25D0D2D5A210A38704.f02t04

Edited July 20, 2017 by kerbiloid

[peadar1987]

Seeing the title, I thought you might be looking to blackmail Jupiter or something

[Steel]

11 hours ago, Cadet_BNSF said:

So I got a new Mars globe, and as I was marveling at the beauty of Mars, I had a question come to me, since dirt on Earth can also be called earth, would dirt on Mars be called mars or earth?

 

1 hour ago, kerbiloid said:

Regolith is not a dirt, it's a dust or a sand.

Depends on definition of "dirt" or "mud".

Are boots covered with soil dirty? Muddy?
Are boots covered with clay dirty? Muddy?
Are boots covered with dust dirty? Muddy? Just dusty?

If treat any pulp-alike pollution as dirt, then wet regolith would be a dirt. Dry regolith is probably just a dust.

If "dirt"/"mud" means only pollution made with Earth-like soil, then no. 
Originally there was no "soil" on Earth, only eroded rock (i.e. regolith), or residual soil.

Real soil has appeared when microorganisms had appeared, spread around and began to die.
Their organics mixed with regolith is what we call soil.

(This was a key moment, because allowed plants to cover the ground and prevent the landscape erosion)

Upd.
Btw an offtop about Mars ground
http://onlinelibrary.wiley.com/doi/10.1002/2017GL074002/abstract;jsessionid=EF0C893EE4D8AA25D0D2D5A210A38704.f02t04

I think this question is tough because of all the symantics involved. "Dirt" is a bit of an Americanism and (as @kerbiloid points out above) means you can end up confusing "dirt" (soil) and "dirt" (as in dirty, something unclean) which are two different concepts. "dirt" (i.e dirty) means unclean - and so has nothing to do with what causes the unclean-ness -  where as "dirt" (soil) is the organic material that covers most of the ground. Most people (at least where I'm from) in the UK call it "soil", in order to avoid the confusion.

With regards to the OP's question, dirt/soil (as many others above have pointed out) does not exist on Mars due to lack of organics. The surface material is called "regolith" (again, thanks, to those above) much like the moon.

In regards to what you could call soil/dirt if you took it to Mars, IMO you would probably still call it "earth" because it's name is not actually a reference to where it is found, it's just an artifact of the complex evolution of the english language. You'd probably want to stick to soil/dirt to avoid confusion though.

Edited July 20, 2017 by Steel

[Nibb31]

You can call it what you want, but the word for it is regolith.

Edited July 20, 2017 by Nibb31

[Kryten]

 Regolith with particles below 1cm in size is referred to soil by planetary scientists (e.g. in this paper), similar to how anything heavier than helium is metal to an astronomer. 

[Green Baron]

Well, Regolith encompasses everything that is on top of an otherwise solid body, regardless of chemistry and composition and history. Earthly soil in whatever appearance is regolith, as is every loose sediment(*) regardless of where it lingers about, or the billion year old dust on celestial bodies. But nobody would assume that they have a connection other than that they are "loose and on top". Otoh classification of sediments on Earth is one tough field, i can tell you, i once had to do the exam twice and others were less lucky :-)

So OPs question maybe wasn't meant in that way but on second thought is worth thinking over because one day we will have to describe Mars' cover as well, the "dirt" that lies on the "marsology". Apparently there were sedimentary processes on Mars billions of years ago, maybe very slow still in some places today, there are visually different surface chemisms e.g. on Ceres. I'm not speaking of structures that were possibly formed by internal processes (like Europa's surface, or Pluto) but really "stuff on top". That may sound trivial, but like on earth, if processes work/worked similar on Mars, we could by finding an appropriate classifaction, judge how those landscapes formed. So it is shrug shoulder regolith as long as viewed from far away, but when actually there it'll turn into debris flow, river bed, moraine, drift line, etc. pp.

(*) "sediment" is one basic category of three for the classification of rocks on Earth, maybe not or only partly applicable on Mars.

 

Edited July 20, 2017 by Green Baron

[Green Baron]

19 minutes ago, Kryten said:

 Regolith with particles below 1cm in size is referred to soil by planetary scientists (e.g. in this paper), similar to how anything heavier than helium is metal to an astronomer. 

Nice example :-) "Soil" on earth indeed has the connotation of "biology and small grained mineralogy mixed up, covering the geology". If used to describe the blanket on other bodies one has to define what is meant by "soil".

I i was asked (which is not the case but nevertheless) i would suggest to leave "soil" to it's original meaning for a subcategory of regolith on earth and find something more specific for the moon's cover. It is not that thrilling and varied anyway ... :-)

Edited July 20, 2017 by Green Baron