What environmental conditions would create compounds not found on earth?

Question

My world is spread across thousands of planets in thousands of star systems, with a sort of United Nations (of Planets) acting as intermediary to ensure peace and prosperity between the planets.

Each planet has different cultures, and different materials, which has created an interplanetary shipping industry so that Earthlings can enjoy lighter spacecraft made out of Abian steel, stronger buildings made with Benoite cement, and so on. Abians, I might add, are particular fans of Earth chocolate.

Now for real-world scientific justification, a few of our solar systems' gas giants have diamond rain, as a methane-rich atmosphere and very high pressure create the perfect environment for diamond formation. But diamonds aren't too uncommon on earth. Other than differences in innovation on different planets, what environmental conditions would allow for the formation of materials and compounds that don't naturally form on Earth, or form only in very trace quantities, while still allowing for these materials to be brought back to Earth without degrading or decomposing?

Answer 1

A planet with a little chlorine in it's atmosphere may boast trees of plastic (Idea courtesy of and sourced by Artifexian on YouTube)! A planet rich in ozone may yield explosive ozonides and peroxides! Not to mention how oxygen is unstable and reactive but is present almost solely due to life! Lifeforms on another world may generate high explosives, superacids, or photosynthetic compounds not found anywhere else! Think about penicillin! Oil! Coal! Carbonate minerals! All common on Earth but absent on other worlds in our solarsystem.

Answer 2

What you need is an excuse as why a certain good is WAY CHEAPER in System A than in System B, because with that tech level it's certain that goods can be reverse engineered and synthesised. The only thing stopping that is economics, so a FTL trip to another star system to deliver Good A is more viable than making a factory right on the spot

Answer 3

It should be noted that we can't frequently know what exact conditions would lead to formation of something that we (basically) don't know about. Your point in case, we know of diamond rains on Jupiter, but we don't necessarily know what else might be there - say, some unobtainium which we don't even have on Earth or maybe don't know it exists.

Nevertheless, we can go the other way, and try to imagine conditions for something we do know to happen (as your diamond rain).

If you want something more exotic, I invite you to check out superheavy elements. On Earth, we usually just (barely) synthesise them in miniscule quantities, and they last for only smallest fractions of seconds -- most of them have short half lives and they fall apart into other elements.

However (!), it is predicted that due to periodic properties of elements, when there are the magic number of protons in nuclei (and double magic if there is magic number of neutrons as well), there should exist pretty stable superheavy elements. We have synthesised some of them, and it is predicted that there should exist a whole island of stability of them.

It is even speculated that such elements may occur naturally:

Similarly, in a 2013 experiment, a group of Russian physicists led by Aleksandr Bagulya reported the possible observation of three cosmogenic superheavy nuclei in olivine crystals in meteorites. The atomic number of these nuclei was estimated to be between 105 and 130, with one nucleus likely constrained between 113 and 129, and their lifetimes were estimated to be at least 3,000 years

Now, I can't give you exact conditions of how these elements may occur naturally, because nobody knows if they do. However, they might, and reading their descriptions in Wikipedia and elsewhere might give some ideas.

Answer 4

Biological products

You already hinted out the best answer, biological products. Nature has created solutions and materials we would never have dreamed of. Synthesising wood would be incredibly difficult cost prohibitivly expensive process, but plants on earth make it for free from water and sunlight. If the biology of your aliens is significantly different who knows what useful products they make. maybe they have a tree that makes its trunk out of foam aluminum composite or carbon nanotubes. Nature has had a long time to brute force solution we would never conceive of. Many of these materials are flukes of evolutionary history that will likely never evolve on another planet.

You may go to harvest or trade, but you could also also going just to get breeding samples so we can grow them, but to do that successfully you need to understand their biosphere. Even just knowing how the plants there do it could be worth billions of dollars. then you have the weird things like drugs, spices, or even just exotic materials, art, or pets.

I remember a short story about a planet where the locals weave a cordage out some local plant extract that is stronger than any sythetic cable and is highly sought after for space elevator, skyhook cables, and string instruments. A large percentage of the planets exports were this one product.

Another has a torus world lifeform that produced a material that behaved like a liquid even in hard vacuum, and was highly desirable as a lubricant/hydraulic fluid for space vehicles.

Answer 5

Helium-3 is much more abundant on the Moon than on Earth. The main reason is that the Moon does not have a magnetic field and Helium-3 is deposited from the solar wind. The magnetic field present on Earth prevents solar wind to hit Earth.

Answer 6

Chemistry works the same wherever you go: given the same reagents and the same conditions, you get the same products.

what environmental conditions would allow for the formation of materials and compounds that don't naturally form on Earth, or form only in very trace quantities, while still allowing for these materials to be brought back to Earth without degrading or decomposing?

Different conditions than those present on Earth, of course.

As an example, if you have an atmosphere without oxidizing elements like oxygen you can find native substances like iron, copper and carbon, which would otherwise be found in their oxidized state.