Strangelets are tiny but dense clumps of matter that were theorized two decades ago, but no one has ever seen them or proved they exist. They are thought to have formed during the Big Bang and inside dense stars and are made of subatomic particles called quarks and strange quarks. They are presumed to be 10 million times more dense than lead and to travel largely undetected through space at roughly 1 million mph.

If they are firmly determined to exist, strangelets could help explain some of the so-called dark matter of the universe, missing mass that scientists say must be there based on the behavior of galaxies that could only be caused by gravity from some unseen stuff.

A team of researchers from Southern Methodist University in Texas dug through old seismic records looking for signs of strangelets passing through, according to the article. They reportedly found two separate 1993 events in which localized earthquakes occurred and were matched seconds later by similar events on another part of the planet.

One event was recorded by seismometers in Turkey and Bolivia, then followed 26 seconds later by some shaking near Sri Lanka. The other event began in Australia and Bolivia and was apparently matched 19 seconds later off Antarctica.

Researchers believe other entirely harmless particles, called neutrinos, routinely pass through Earth undetected.

It is not clear what if any effect a strangelet impact might have on inhabited areas.

"It's very hard to determine what the effect would be," said Eugene Herrin in the Telegraph article. "There would probably be a tiny crater but it would be virtually impossible to find anything."

Herrin said the seismic records were consistent with the theory of strangelets. But Frank Close, a particle physicist at Oxford University, said more examples would have to be found and studied to rule out other possibilities.

SPACE.briefs: Strange Tidbits from around the Universe