A fireball breaking apart in Earth's atmosphere.

Well folks, it’s still not aliens.

It’s common for speeding rocks from space to blow up in our atmosphere, events called « fireballs. » In 2014, such a meteor exploded over the Pacific Ocean, somewhere near Papua New Guinea. An intrigued group of scientists led by Harvard astronomer Avi Loeb — who to the chagrin of the astronomical community makes dubious extraterrestrial claims — followed a seismometer ping to the region and then searched the nearby seafloor in 2023. They plucked up some tiny metallic spheres (which are found on seafloors globally), and concluded the material could have come from another solar system, or might have an « extraterrestrial technological origin. »

Now, a group of seismologists, who are experts in analyzing vibrations picked up by seismometers, have thrown cold water on that conclusion.

The seismic reading that attracted Loeb and company almost certainly wasn’t an exploding meteor. Instead, the seismometer on the ground in Papua New Guinea had picked up a far more mundane event.

« The most likely explanation is probably a truck dropping someone off or picking someone up — not an interstellar meteor or aliens, » Benjamin Fernando, a planetary seismologist at Johns Hopkins University who led the research, told Mashable.

That means the tiny round objects the fireball-hunters found, called « spherules, » almost certainly weren’t from the meteor that exploded over the expansive Pacific Ocean. These tiny objects are likely just normal cosmic material found all over Earth. You can even commonly find these tiny meteorites on your roof.

« They look very similar to things we see at the bottom of the ocean all over the world, » Fernando said.

The new seismology research, which has been submitted for peer-reviewed publication in a science journal, will be presented on March 12 at the Lunar and Planetary Science Conference in Houston, Texas.

« The most likely explanation is probably a truck dropping someone off or picking someone up — not an interstellar meteor or aliens. »

The results underscore the particular seismometer reading in Papua New Guinea — that the meteorite-hunters used to pinpoint the trajectory of their suspected interstellar fireball — wasn’t unusual or unique. In fact, for months that specific seismometer had recorded hundreds of similar signals.

These vibration signals weren’t happening randomly, Fernando emphasized. They were specifically happening during daytime, just like the purported fireball reading. « That’s a strong indicator of something caused by humans, » he said.

Indeed, as the satellite images below show, a road travels right by the seismometer. What’s more, the seismometer signal follows the direction of the road. And the waves reflect the activity of a rumbling truck; not an exploding meteor.

An image showing the truck road traveling right by the seismometer. This seismometer regularly detects signals, likely from passing trucks, during the daytime.
An image showing the truck road traveling right by the seismometer. This seismometer regularly detects vibration signals, likely from passing trucks, during the daytime. Credit: Google Earth / CNES / Airbus

The truck road shown in yellow. The seismometer is at center.
The truck road shown in yellow. The seismometer is at center. Credit: Google Earth / CNES / Airbus / Johns Hopkins University

As for the fireball that did indeed explode over the Western Pacific Ocean in 2014, the seismologists found that other seismometer detections, located in Australia and Palau, show the blast likely happened over 100 miles from where the supposedly interstellar spherules were taken.

« The fireball location was actually very far away from where the oceanographic expedition went to retrieve these meteor fragments, » Fernando added in a statement. « Not only did they use the wrong signal, they were looking in the wrong place. »

To further buttress their argument, Fernando said the team would like the opportunity to test the seismometer readings when a truck was actually driving by — but haven’t found someone with the capacity to work with them, yet.

In August 2014, a NASA camera spotted a bright fireball exploding over Tennessee.
In August 2014, a NASA camera spotted a bright fireball exploding over Tennessee. Credit: NASA

There remains zero evidence that life exists anywhere beyond our planet. And claims about evidence of life or that some material was produced unnaturally in the deep cosmos demand an extremely high-bar of proof — or more accurately, many lines of proof.

Astronomers, planetary scientists, and astrobiologists, however, are carefully scrutinizing objects in our solar system and beyond for places that might support life as we know it. These include ocean worlds in our own solar system, like Enceladus and Europa, and planets many light-years away in our Milky Way galaxy. There are likely trillions of planets beyond our solar system (called « exoplanets« ) in just our galaxy alone, NASA explains. Perhaps, for example, there might be suitable conditions for life on a distant « super-Earth » that harbors the right temperatures for liquid water to exist.

« So far, the only life we know of is right here on our planet Earth, » the space agency said. « But we’re looking. »