Dinosaurs may have met their end not over months or years, but in the span of a brutal afternoon. A new study in the Journal of Geophysical Research: Biogeosciences argues that the asteroid that hit Mexico's Yucatán 66 million years ago likely cooked much of the life on land within hours, thanks to a superheated shroud of rock vapor in the atmosphere, Popular Science reports. Using computer models and dust evidence from the impact layer, researchers found that this vapor blanket could have driven ground temperatures to lethal levels, igniting near-instant wildfires worldwide. "We're in the realm where we might be essentially killing off everything within that first hour or two," co-author and Purdue planetary scientist Brandon Johnson says in a release.
Previous studies found chunks of condensed rock vapor were blasted into the sky before raining down, generating intense heat, but not enough to instantly cook plants. The new study found the extra dust layer significantly increased surface heat to the point of instantaneous kills, bolstering the idea that the strike itself—not just the long, cold "impact winter" that followed—was immediately catastrophic for dinosaurs. Yet the work may also fit with the slower-death hypothesis: once the fires burned out, the same dust that trapped heat could have then blocked sunlight for years, starving ecosystems, researchers say. Evidence for truly global wildfires remains sparse outside North America, and scientists say more data is needed to confirm just how fast the world of the dinosaurs burned.
,
uBlock 
,
and
Ghostery 
)
