> under IUPAC rules that means there can now never be an element called Hahnium

Huh, I didn't know that was a rule, but it sure is. I guess the official rationale is, if someone published a paper talking about "hahnium" while it was under dispute, readers 100 years later shouldn't be confused into thinking it refers to the element that eventually did get that name. But I agree with Kean, it does provide a small portion of justice in this case.

> I'm so disappointed they didn't call element 115 Elerium. Moscovium, forsooth.

As an ex-chemist I am obliged to nitpick that "Elerium-115" would be the term for an isotope with atomic mass 115; its atomic number would as usual be a little less than half that, which would make it not an exotic superheavy at all. All the elements in between molybdenum and barium have at least one isotope with mass 115 (according to http://periodictable.com/Properties/A/KnownIsotopes.an.html), but the only stable isotope with that mass belongs to tin (atomic number 50).

Technetium is in that range, though, the lightest element with no stable isotopes. Maybe the secret of Elerium is that the aliens have figured out how to bulk-synthesize and stabilize what we call technetium-115 (which has a half-life of less than a second under normal conditions) and then induce controlled decay to use it as a power source. Its decay chain is all beta-minus — electrons — which is convenient both for using it as a power source and for not having a radiation shielding problem... and that's maybe as far into Marvel No-Prize territory as we need to go.