VLT observations of interstellar comet 3I/ATLAS II
arxiv.org
arxiv.org
Where does it say there is zero iron? This is an upper bound, not zero.
Remains Undetected. Pretty crystal clear.
I feel like it's more of a meme than a serious thing for most people.
https://www.astralcodexten.com/p/heuristics-that-almost-alwa...
Looking at you Angry Astronaut.
In any case, assumptions shouldn’t be made either either way what it might be, which is the reason to gather more data.
There is so much more information available in the electromagnetic spectrum than just the narrow range a human eye can see
measuring pressure with line broadening!?!
Salts without sodium give other colors. IIRC cooper gives a green color. This is used by firecrackers makers to get nice colors, and also in the chemistry lab to detect the composition of some salts.
After studding this king of stuff for a few centuries, we have a very good idea of how each element changes the color of the flame, or absorbs some colors of the light that pass trough the mist.
astronomy technology has been improving rapidly and the VLT is one of the best implementations for this kind of problem right now.