All articles tagged with #chicxulub
A 10-km asteroid hit the Yucatán 66 million years ago, vaporising sulfur-rich rocks beneath it and lofting sulfur-bearing gases and dust into the atmosphere; the impact angle and local geology amplified the effect, triggering global cooling and a mass extinction, though the exact atmospheric recipe is still being refined by researchers.
A new study argues that a thick layer of fine silicate dust formed from rock vapor at the Chicxulub impact may have trapped heat and amplified Earth's post-impact heat pulse to about 3.5 times higher than models considering only the spherules, potentially igniting grass, lichens, and pine needles and delivering roughly 17 times the lethal thermal dose to exposed animals. This dust layer could also help block sunlight, fueling a prolonged “impact winter.” Global wildfire evidence is not yet confirmed beyond North America, but the proposed mechanism is published in JGR Biogeosciences (July 28).
The article asks if humanity could detect an extinction-level asteroid before impact, using the dinosaurs’ 10 km carbonaceous impactor as a case study. It explains that warning time depends on the object’s origin, speed (~21 km/s), and whether it brightens from outgassing; best-case scenarios could offer weeks to a month of naked-eye visibility if the body comes from the night side and becomes bright, but more typical cases might yield only days or hours, or no warning at all if it’s sun-ward or depleted of volatiles. It also highlights how albedo and orbital geometry affect detectability, and stresses the need for planetary defense to gain decades of lead time for meaningful intervention.
About 66 million years ago, a 10–15 km asteroid hit the Yucatán, creating the Chicxulub crater (~180 km across) and releasing energy equivalent to about 5 billion Hiroshima bombs. The impact ejected vast material, lofting dust, soot, and aerosols that blocked sunlight and likely caused a prolonged “impact winter,” leading to the mass extinction of non-avian dinosaurs and roughly 75% of species. Survival was uneven: around 12% of land species persisted, while freshwater life fared better (~90%). The crater’s link to the extinction was established in the 1990s, with 2016 drilling confirming deep-Earth material in the peak ring; scientists continue debating the exact roles of soot versus sulfur and how long the dark interval lasted.
The Chicxulub impact 66 million years ago released molten debris that heated the upper atmosphere and sulfur- and soot-rich aerosols that blocked sunlight for years, triggering a drastic cooling that collapsed photosynthesis and reshaped life on Earth; while fires may have started in some regions, debates continue about how much the global die-off was due to heat, dust, or smoke, with survivors mainly among small, burrowing or detritus-eating species.
New modeling suggests the Chicxulub impact's global killing power hinged on striking hydrocarbon-rich, sulfur-bearing coastal rocks. The study estimates such geology could generate enough stratospheric soot to trigger 8–11°C global cooling, a major driver of the mass extinction, whereas rocks with lower hydrocarbon content would have caused milder effects. The claim is model-based and contingent on late-Cretaceous geology and the impact angle, and while it fits with related research, it remains not a settled consensus.