(Press-News.org) Analysis of ocean sediments has surfaced geochemical clues in line with the possibility that an encounter with a disintegrating comet 12,800 years ago in the Northern Hemisphere triggered rapid cooling of Earth’s air and ocean. Christopher Moore of the University of South Carolina, U.S., and colleagues present these findings in the open-access journal PLOS One on August 6, 2025.
During the abrupt cool-off—the Younger Dryas event—temperatures dropped about 10 degrees Celsius in a year or less, with cooler temperatures lasting about 1,200 years. Many researchers believe that no comet was involved, and that glacial meltwater caused freshening of the Atlantic Ocean, significantly weakening currents that transport warm, tropical water northward. In contrast, the Younger Dryas Impact Hypothesis posits that Earth passed through debris from a disintegrating comet, with numerous impacts and shockwaves destabilizing ice sheets and causing massive meltwater flooding that shut down key ocean currents.
However, the impact hypothesis has been less well supported, lacking any evidence from ocean sediments. To address that gap, Moore and colleagues analyzed the geochemistry of four seafloor cores from Baffin Bay, near Greenland. Radiocarbon dating suggests the cores include sediments deposited when the Younger Dryas event began. To study them, the researchers used several techniques, including scanning electron microscopy, single-particle inductively coupled plasma time-of-flight mass spectrometry, energy dispersive spectroscopy, and laser ablation inductively coupled plasma mass spectrometry.
The analysis detected metallic debris whose geochemistry is consistent with comet dust. These occurred alongside microscopic spherical particles whose composition indicates a mostly terrestrial origin, with some materials believed to be extraterrestrial—suggesting these microspherules could have formed when comet fragments exploded just above or upon hitting the ground, melting materials together. The analysis also uncovered even smaller nanoparticles with high levels of platinum, iridium, nickel, and cobalt, which can be signs of extraterrestrial origin.
Together, these findings indicate a geochemical anomaly occurring around when the Younger Dryas event began. However, they do not provide direct evidence supporting the impact hypothesis. More research is needed to confirm whether the findings are indeed evidence of impact, and to firmly link an impact to climate cooling.
Dr. Christopher R. Moore adds: "Our identification of a Younger Dryas impact layer in deep marine sediments underscores the potential of oceanic records to broaden our understanding of this event and its climatological impacts."
Dr. Mohammed Baalousha adds: "It is great to implement our unique nano-analytical tools in a new area of study, namely the analysis of 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."
Dr. Vladimir Tselmovich adds: "Collisions of the Earth with comets led to catastrophes leading to climate change, to the death of civilizations. One of these events was a catastrophe that occurred about 12,800 years ago. 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. 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. The results obtained confirm the hypothesis that the Earth collided with a large comet about 12,800 years ago."
Author interview: http://plos.io/4lTL04w
In your coverage, please use this URL to provide access to the freely available article in PLOS One: http://plos.io/4mfhOEH
Citation: Moore CR, Tselmovich VA, LeCompte MA, West A, Culver SJ, Mallinson DJ, et al. (2025) A 12,800-year-old layer with cometary dust, microspherules, and platinum anomaly recorded in multiple cores from Baffin Bay. PLoS One 20(8): e0328347. https://doi.org/10.1371/journal.pone.0328347
Author countries: U.S., Russian Federation, U.K., Czechia, Australia
Funding: This work made use of the University of Utah USTAR shared facilities supported, in part, by the MRSEC Program of the NSF under Award #DMR-1121252. G.K. appreciates the support from the Czech Science Foundation (Grant 23-06075S). We also thank the thousands of donors and members of the Comet Research Group (Grant 24-01) who have been crucial in making this research possible. In particular, we thank Eugene Jhong, who provided substantial gifts supporting this research to the University of South Carolina (C.R.M.) and the University of California, Santa Barbara (J.P.K). V.A.T.’s research was carried out within the framework of the Borok Geophysical Observatory, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, state task nos. FMWU-2022-0026. The funders had no role in study design, data collection and analysis, decision to publish, or the preparation of the manuscript.
END
Ocean sediments might support theory that comet impact triggered Younger Dryas cool-off
Northern Hemisphere cooling 12,800 years ago generally thought to be caused by glacial meltwater; new geochemical evidence might support comet impact
2025-08-06
ELSE PRESS RELEASES FROM THIS DATE:
Waiting in line: Why six feet of social distancing may not be enough
2025-08-06
August 6, 2025
Waiting in Line: Why Six Feet of Social Distancing May Not Be Enough
Study, led by undergraduate physics majors at UMass Amherst and researchers at University of Cadiz, sharpens our understanding of how airborne-communicable diseases travel
AMHERST, Mass. – We all remember the advice frequently repeated during the COVID pandemic: maintain six feet of distance from every other human when waiting in a line to avoid transmitting the virus. While reasonable, the advice did not take into account the complicated fluid dynamics governing how the airborne particles ...
Toxic well water will affect household pets first, new study finds
2025-08-06
Dogs drink water wherever they happen to find it — a puddle, a pond, a toilet. But the stuff in their actual water bowls almost always comes from the same tap their owners use. When that water is contaminated, both dogs and humans may suffer.
The risk is especially high for the 15 million American households that rely on private wells, according to a new Virginia Tech study in the journal PLOS Water. In dog drinking water sampled from wells across the country, 64 percent contained excessive levels of at least one potentially toxic heavy metal, such as lead, iron, sulfur, or arsenic.
Whatever’s ...
Some young suns align with their planet-forming disks, others are born tilted
2025-08-06
(Santa Barbara, Calif) — Researchers at UC Santa Barbara, The University of Texas at Austin, Yale University and National Taiwan Normal University have found that a fair number of sun-like stars emerge with their rotational axis tilted with respect to their protoplanetary disks, the clouds of gas and dust from which solar systems are born.
“All young stars have these discs, but we’ve known little about their orientations with respect to the spin axis of the host stars,” said UCSB associate physics professor Brendan Bowler, who studies how planets form and evolve through their orbits and atmospheres, and is senior author of a study in ...
Neighbors matter: Community cohesion boosts disaster resilience, Texas A&M study finds
2025-08-06
A study from the Texas A&M University School of Public Health sheds new light on the relationship between community cohesion prior to a natural disaster and resilience after one, with possible policy applications for public health and emergency preparedness practitioners.
“Recent events have reminded us that resilience isn’t just about bricks and budgets,” said community health expert Garett T. Sansom, who led the study. “In part, it’s also about bonds between neighbors.”
Until now, he added, little has been known about the mechanisms ...
Virtual reality shows promise in easing stress for cardiac patients, UCLA Health study finds
2025-08-06
Virtual Reality Shows Promise in Easing Stress for Cardiac Patients, UCLA Health Study Finds
Living with cardiovascular disease often takes a serious emotional toll - and with stress known to worsen heart health, there’s growing interest in low-risk, innovative ways to help patients cope. New research from UCLA Health suggests that virtual reality (VR) may offer a promising tool to ease psychological stress and support heart health.
In a pilot study involving 20 patients from UCLA’s ...
MBARI researchers deploy new imaging system to study the movement of deep-sea octopus
2025-08-06
MBARI researchers have developed an innovative imaging system that can be deployed at great depths underwater to study the movement of marine life. The team used the system to study deep-sea octopus and shared their findings in the scientific journal Nature.
EyeRIS (Remote Imaging System) can capture detailed three-dimensional visual data about the structures and movement of marine life in their natural deep-sea habitat. MBARI researchers integrated EyeRIS on board a remotely operated vehicle to observe deep-sea pearl ...
Scrambled RNA nudges millions of people towards type-2 diabetes
2025-08-06
Mutations in a single gene, HNF1A, are known to cause MODY3, a rare, early onset form of diabetes. Smaller scale mutations in the very same gene are also common and quietly nudge millions of people toward type-2 diabetes. A study published today in Cell Metabolism reveals why.
Researchers at the Centre for Genomic Regulation (CRG) in Barcelona show it’s fundamentally a problem of insulin-producing β‑cells. Using mouse models, they switched HNF1A off in different tissues and cell types including the liver, the gut and both α and β‑cells in the pancreas, ...
Big heart, acute senses key to explosive radiation of early fishes
2025-08-06
An international team led by scientists from the Canadian Museum of Nature and the University of Chicago reconstructed the brain, heart, and fins of an extinct fish called Norselaspis glacialis from a tiny fossil the size of fingernail and found evidence of change toward a fast-swimming, sensorily attuned lifestyle well before jaws and teeth were invented to better capture food.
“These are the opening acts for a key episode in our own deep evolutionary history,” said Tetsuto Miyashita, who is a research scientist with the ...
Getting sticky: The highest-performing underwater adhesive hydrogel polymer
2025-08-06
Hydrogels are a permeable soft material consisting of polymer networks and water with applications ranging from bio-medical engineering to contact lenses. Intrinsic to hydrogels is the ability to endow diverse characteristics by modifying their polymer networks. Professor Gong’s research lab at WPI-ICReDD, Hokkaido University, specializes in hydrogel technology and has engineered hydrogels with self-strengthening, self-healing, underwater adhesion properties and more. For adhesive hydrogels, achieving instant, strong, and repeatable underwater adhesion is a prevailing challenge.
Through a combination of data mining and machine learning, Professor Gong, Professor Takigawa, Professor ...
The health impact of wildfires in Los Angeles County and Maui
2025-08-06
The Health Impact of Wildfires in Los Angeles County and Maui
JAMA and JAMA Network Open
EMBARGOED FOR RELEASE: 11:00 A.M. ET, WEDNESDAY, AUGUST 6, 2025
About The Studies: JAMA and JAMA Network Open are publishing studies examining the health impact of wildfires in Los Angeles County in January 2025 and in Maui in August 2023. Among the findings:
JAMA
Excess Deaths Attributable to the Los Angeles Wildfires
While there were only 30 direct fatalities from the Los Angeles wildfires, this study estimates that 440 deaths from January 5 to February 1, 2025, were attributable to the wildfires. These additional deaths likely reflect a combination of factors, including increased ...
LAST 30 PRESS RELEASES:
Transcatheter or surgical treatment of patients with aortic stenosis at low to intermediate risk
Promising new drug for people with stubborn high blood pressure
One shot of RSV vaccine effective against hospitalization in older adults for two seasons
Bivalent RSV prefusion F protein–based vaccine for preventing cardiovascular hospitalizations in older adults
Clonal hematopoiesis and risk of new-onset myocarditis and pericarditis
Risk of myocarditis or pericarditis with high-dose vs standard-dose influenza vaccine
High-dose vs standard-dose influenza vaccine and cardiovascular outcomes in older adults
Prevalence, determinants, and time trends of cardiovascular health in the WHO African region
New study finds that, after a heart attack, women have worse prognosis when treated with beta-blockers
CNIC-led REBOOT clinical trial challenges 40-year-old standard of care for heart attack patients
Systolic blood pressure and microaxial flow pump–associated survival in infarct-related cardiogenic shock
Beta blockers, the standard treatment after a heart attack, may offer no benefit for heart attack patients and women can have worse outcomes
High Mountain Asia’s shrinking glaciers linked to monsoon changes
All DRII-ed up: How do plants recover after drought?
Research on stigma says to just ‘shake it off’
Scientists track lightning “pollution” in real time using NASA satellite
Millions of women rely on contraceptives, but new Rice study shows they may do more than just prevent pregnancy
Hot days make for icy weather, Philippine study finds
Roxana Mehran, MD, receives the most prestigious award given by the European Society of Cardiology
World's first clinical trial showing lubiprostone aids kidney function
Capturing language change through the genes
Public trust in elections increases with clear facts
Thawing permafrost raised carbon dioxide levels after the last ice age
New DNA test reveals plants’ hidden climate role
Retinitis pigmentosa mouse models reflect pathobiology of human RP59
Cell’s ‘antenna’ could be key to curing diseases
Tiny ocean partnership between algae and bacteria reveals secrets of evolution
Scientists uncover cellular “toolkit” to reprogram immune cells for cancer therapy
Blocking protein control pathway slows rhabdomyosarcoma growth in mice
2026 Hertz Fellowship Application Now Open
[Press-News.org] Ocean sediments might support theory that comet impact triggered Younger Dryas cool-offNorthern Hemisphere cooling 12,800 years ago generally thought to be caused by glacial meltwater; new geochemical evidence might support comet impact