The densest naturally occurring element on Earth is osmium, boasting a remarkable density of 22.59 grams per cubic centimeter.
This surpasses even the density of Earth’s inner core. But curiously, there are objects in our Solar System, particularly asteroids, which have been observed to be even denser than osmium. This density perplexes scientists, as asteroids lack the mass to press minerals into such an ultradense state.
These observations have given rise to the idea that there could be undiscovered stable elements beyond our known periodic table. Elements with atomic numbers exceeding 118 haven’t been observed to date.
However, theoretical research indicates a potential “island of stability” around atomic number 164. These superheavy elements could be resistant to rapid radioactive decay.
33 Polyhymnia, an asteroid nestled in the asteroid belt with a diameter of 50 to 60 kilometers, presents one such puzzle. It has been reported to have a density of 75.28 grams per cubic centimeter, categorizing it as a potential compact ultradense object (CUDO).
Although such an extreme measurement is generally suspected to be inaccurate, physicists from the University of Arizona, Evan LaForge, Will Price, and Johann Rafelski, decided to explore the possibility of its physical plausibility.
Using the Thomas-Fermi model, a basic yet effective model of atomic behavior, the researchers delved into the atomic structures of these hypothetical superheavy elements. Their findings supported the theorized “island of stability” around atomic number 164.
Furthermore, they determined the density of this element to lie between 36 and 68.4 grams per cubic centimeter, intriguingly close to the density ascribed to 33 Polyhymnia.
To be clear, this doesn’t confirm that 33 Polyhymnia is indeed ultradense. It simply suggests that if the asteroid’s extreme density measurement is accurate, there’s a plausible explanation rooted in known physics, rather than speculative mystery matter.
The physicists believe their work underlines the effectiveness of the Thomas-Fermi model in analyzing the attributes of potential superheavy elements and sets the stage for further detailed studies.