Elements, Metals, Earth, and the Universe

hey everyone here on ATS. this is my first thread so bare with me. not sure if anything like this has ever been posted here about what im going to talk about, i have been using this site for about 3 years now.

What this topic is about is just my own theory, in no way am i a scientist, or astrologist, just merely a civilian with curiosity and a passion for space exploration.

Hydrogen, Methane, Helium, Nitrogen, Gallium, iron, steel, copper, and all the other elements and metals that our brilliant scientist have discovered are all a part of the composition of this planet. But some of the elements and metals on this planet that are discussed by scientist, are the most common chemical make up of the Universe.
On this planet we have our rare elements, those elements that you do not have large quantities of, however in the world of discovery you dont hear a whole lot of talk or findings or rare elements or even theorized elements. I have done some search on the internet and could not find very much on the topic. The universe is such a vast body filled with trillions of planets and galaxies, so in theory shouldnt there be an extreamly large amount of rare elements out there.
The same goes for metals, you only hear talk of iron and other basic forms of natural metals, but you never hear of any rare types. with the Hubble telescope im sure they should have spotted some sort of material that is unfamiliar. different compositions and such. the further into deep space you go, you are sure to come across some phenomenal forms of material.
So in summary considering the possibility of ``Alien`` types of metals and elements, would that not mean life altering discoveries for our planet if there was a possibility to access these types of materials. Perhaps new forms of alternative fuels, advance propulsion systems, technologies, stronger, lighter, materials. If you think about what these rare elements could do, that perhaps deep space travel is not to far fetched at all. the only problem is that we cannot access these types of material.
So all i can ask all you ATS ers is to give me what your opinion on the matter is, so to speak

There is apparently a lot of helium-3 on the moon, which would make a good fusion fuel, but the expense of getting it from the moon is obviously rather high.

Promethium, an element not found on earth (other than maybe a few grams) has been seen in stars using spectroscopy. I'm not sure whether promethium has very many uses, but there might be some we don't know about since we don't have a lot of it to work with. It can be produced on earth artificially.

I'm not exactly sure what you are looking for, but I thought I'd throw those two out.