An international team of researchers may, just may, have made a radical breakthrough that could rewrite physics and chemistry textbooks.

They claim to have discovered a naturally occurring element with an atomic number (number of protons) of 122 — 30 notches on the periodic table ahead of uranium, long considered the heaviest naturally occurring element.

For decades, physicists have been making artificial elements in supercolliders, only to see most of their creations disintegrate within a short time.

Most elements above atomic number 100 are inherently unstable and get progressively more usntable as you travel upward. The highest discovered one, ununoctium or atomic number 118, has a half-life of 89 milliseconds.

• Click here to visit FOXNews.com's Natural Science Center.

But according to theory, there exists an "island of stability" further out along the periodic table where certain configurations of protons and neutrons would create superheavy but also superstable elements.

So a team led by Amnon Marinov of the Hebrew University of Jerusalem took a different approach. They figured that if superheavy, superstable elements really are possible, then they ought to already exist in nature.

Taking a relatively large amount of thorium, a natural element with the atomic number 90, they fired each and every nucleus in the pile through a mass spectrometer, which catches the atomic weight of nuclei (protons plus neutrons) by analyzing how beams of ions pass through them.

The two isotopes of thorium, with atomic weights of 230 and 232, were most abundant, as were various impurities in the sample.

But there was something else — something with an atomic weight of 292, something never before seen.

The researchers aren't certain, but they figure their unknown substance probably has an atomic number of 122, whose slot on the periodic table already has the temporary name "ununbibium," or "one-two-two-bium."

They also figure its half-life is at least 100 million years — meaning the shores of the long-sought "island of stability" may finally have been reached.

They're ruled out various errors, and are ready to defend their paper, posted Thursday on the math and physics Web site arXiv.org.

• Click here for a relatively easy-to-understand summary of the finding, and here for the PDF version of the highly technical paper.