Scientists have uncovered compelling new evidence from the ocean floor supporting the controversial theory that a disintegrating comet triggered a dramatic global cooling event 12,800 years ago.
The findings, reported by University of South Carolina scientists, involve the discovery of several examples of direct evidence that Earth experienced a series of impacts from a disintegrating comet 12,800 years ago, which caused a period of cooler global temperatures lasting more than a millennium (Editor’s Note: On February 11, 2026, the study discussed in this article was retracted; additional details on the Plos One editor’s decision in this matter can be found here).
Although no direct evidence of the proposed ancient comet was found during the study effort, the researchers believe their findings offer strong geochemical support for a theoretical series of impacts, or more likely, an airburst event, as the cause of a brief and unexplained reversal in warming at the end of the last ice age.
The results offer strong support for the hypothesis “that the Earth collided with a large comet about 12,800 years ago,” study co-author, Dr. Vladimir Tselmovic, said. “The amount of comet dust in the atmosphere was enough to cause a short-term ‘impact winter,’ followed by a 1,400-year cooling period.”
Previous attempts to explain the 1,200-plus years of cooling that began unexpectedly in the middle of an overall global warming trend, known as the Younger Dryas, have resisted the inclusion of a cometary impact. Instead, most models account for the 10-degree Celsius drop through an increase in cold glacial meltwater that flooded the northern Atlantic Ocean. According to those theories, this meltwater runoff significantly weakened currents responsible for transporting warmer tropical water north.
To locate more concrete evidence for the comet impact hypothesis, study leader Dr. Christopher Moore and colleagues reexamined deep ocean floor core samples that include sediments confirmed by radiocarbon dating as being from this time period. Based on the best theoretical impact sites, the team used cores taken from Baffin Bay near Greenland.
To search for clues of comet impacts in the samples, the team employed multiple tools and techniques. According to the team’s statement, they employed scanning electron microscopy, single-particle inductively coupled plasma time-of-flight mass spectrometry, energy-dispersive spectroscopy, and laser ablation inductively coupled plasma mass spectrometry.
When analyzing the findings from the varying tests, the team found chemical traces of metallic debris “whose geochemistry is consistent with comet dust.” The tests also found microscopic spherical “particles” made of mostly terrestrial materials. However, the team stated that spectrographic analysis of the particles revealed materials “believed to be extraterrestrial.” This combination of terrestrial and extraterrestrial materials found in the same location as the metallic debris, they conclude, suggests the microspherules “could have formed when comet fragments exploded just above or upon hitting the ground,” resulting in the two materials melting together.
Finally, the core sample analysis revealed the presence of several smaller nanoparticles with high concentrations of iridium, nickel, platinum, and cobalt. The team notes that these concentration levels “can be signs of extraterrestrial origin.”
“Having studied in detail the microscopic traces of this disaster in Baffin Bay, we were able to find multiple traces of cometary matter, which was identified by the morphology and composition of the microparticles found,” Tselmovich said.
Because the study did not find direct evidence of a cometary impact, such as a crater, the researchers say additional research is required. However, they do propose that taken all together, the test results “indicate a geochemical anomaly occurring around when the Younger Dryas event began.”
“Collisions of the Earth with comets led to catastrophes, leading to climate change, to the death of civilizations,” Dr. Vladimir Tselmovich added. “One of these events was a catastrophe that occurred about 12,800 years ago.”
When describing the value of the team’s research, co-author Dr. Mohammed Baalousha said the study offered an unprecedented opportunity to leverage his group’s “unique nano-analytical tools” for analyzing nanoparticles generated or transported to the Baffin Bay core site during the Younger Dryas.
“We are always happy to implement our tools to support our colleagues and explore new frontiers,” the researcher said.
Dr. Christopher R. Moore agreed, noting that the team’s identification of a Younger Dryas cometary impact layer in deep marine sediments “underscores the potential of oceanic records to broaden our understanding of this event and its climatological impacts.”
The study “A 12,800-year-old layer with cometary dust, microspherules, and platinum anomaly recorded in multiple cores from Baffin Bay” was published in PLOS One.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.