Scientists have long debated the likelihood and impact of cosmic airbursts, a type of extraterrestrial event that can cause extreme damage through high temperatures and pressures. Now, new research suggests that these events may be more common than previously believed.
According to Professor James Kennett of UC Santa Barbara, touchdown airbursts are a form of cosmic impact that don’t necessarily form craters, but still have devastating effects on the environment. The researchers have identified evidence for several cosmic airbursts in different locations around the world, including the North Atlantic deep-sea floor and ancient desert civilizations.
The study found impact proxies, such as rare elements and minerals, molten glass, and shocked quartz, which are formed when extraterrestrial material explodes above ground. These findings were presented in four recently published papers, providing new evidence for the high temperatures and pressures associated with cosmic airbursts.
One significant discovery was made at Baffin Bay, where researchers found impact proxies in ocean sediments associated with the Younger Dryas Impact Hypothesis (YDIH). This hypothesis proposes that a fragmented comet exploded above Earth 12,800 years ago, triggering an anomalous global cooling period and mass extinctions.
The study also sheds light on the difficulty of detecting touchdown airbursts. Since these events don’t typically form craters, researchers must rely on indirect evidence, such as impact proxies in marine sediments or shallow seasonal lakes.
Recent discoveries have confirmed that a shallow seasonal lake near Perkins, Louisiana, may be an impact crater formed during the Younger Dryas Boundary event. The researchers also analyzed sediment from the Tunguska event in Siberia and Tall el-Hammam in Jordan, finding evidence of cosmic airbursts.
These findings suggest that cosmic impacts, particularly touchdown airbursts, may occur more frequently than previously thought. Professor Kennett notes that these events possess much more destructive potential than classic crater-forming asteroidal impacts, emphasizing the importance of studying these phenomena to better understand their effects on our planet.
Source: https://www.futurity.org/cosmic-airbursts-3290482