An archeological dig has uncovered evidence of a massive cosmic airburst event approximately 3,600 years ago that destroyed an entire city near the Dead Sea in the Middle East. The event was larger than the famous Tunguska airburst event in Russia in 1908, with a blast 1,000 times more powerful than the Hiroshima atomic bomb. The event flattened the thriving city of Tall el-Hammam, located in what is now Jordan.
Using evidence unearthed in the dig along with an online impact calculator, the researchers estimate a space rock approximately 50 meters wide exploded about 4 km (2.5 miles) above the Earth, sending a blinding flash and a wave of heat at 2,000 degrees (3,600 F). This would have immediately incinerated wood structures and bodies, and melted any metal objects like swords or spears, and even pottery and mudbrick structures.
But the destruction wasn’t over. A few seconds later, a massive shockwave leveled everything, including a 4-to-5-story palace complex and a large 4-m-thick mudbrick fortification wall.
The authors of the paper, published in Nature Scientific Reports, say that although this doesn’t fall into their area of expertise, “an eyewitness description of this 3600-year-old catastrophic event may have been passed down as an oral tradition that eventually became the written biblical account about the destruction of Sodom.” Sodom was the city, which, according to biblical texts, was destroyed for its lecherousness, with stones and fire falling from the sky. However, this story originates from a time when many natural disasters were blamed on the anger of the gods.
In many sites in the Middle East, archeological digs or studies reveal several layers of past habitation that have religious or nationalist significance for more than one ethnic group, where the victor of wars or conquests built upon the ruins of the city or buildings it just conquered – with the cycle repeating over the millenniums.
The region around Tall el-Hammam is different however, in that since the end of the Middle Bronze Age, this region in eastern Jordan suffered some sort of civilization-ending calamity, and remained unoccupied for the next five-to-seven hundred years. Additionally, this area was originally one of the most productive agricultural lands in the region, and which had supported flourishing civilizations continuously for at least 3,000 years. But suddenly the soil in the region was inundated with salts where nothing would grow.
This mystery is being investigated by researchers from multiple universities and organizations and archeologists have been working at the Tall el-Hammam site since 2005. Even the earliest archaeological excavations revealed the presence of unusual materials, including melted mudbrick fragments, melted pottery, ash, charcoal, charred seeds, and burned textiles, all intermixed with pulverized mudbrick. Additionally, further digs revealed incredible destruction.
The researchers eliminated the usual suspects, such as warfare, fires, volcanic eruption, or earthquakes because these events were unlikely to cause the kind of destruction they found at the site, and none of those events could have produced the intense heat required to cause the melting that they found. But then the excavators found spherules of shocked quartz, a tell-tale sign of an intense and sudden high-temperature event such as a cosmic impact.
“After eleven seasons of excavations, the site excavators independently concluded that evidence pointed to a possible cosmic impact,” the team wrote in their paper. “They contacted our outside group of experts from multiple impact-related and other disciplines to investigate potential formation mechanisms for the unusual suite of high-temperature evidence.”
While an asteroid impact could have created all the evidence found by the archaeologists, that type of event was dismissed because there was no evidence of a crater in the area.
Using an impact calculator, a group of 21 researchers determined the most likely cause of the destruction was a cosmic air burst caused by a comet or meteor. Their calculations showed such an event would result in the unusal destruction found by archaeologists, such as pottery sherds with outer surfaces melted into glass, some bubbled as if they were boiled, mudbrick fragments and “extreme disarticulation and skeletal fragmentation in nearby humans.”
Also, an airburst-related influx of salt produced hypersalinity in the surrounding soil, making agriculture impossible, causing a 600-year-long abandonment of about 120 regional settlements within a 25-km radius.
“We think the explosion may have vaporized or splashed toxic levels of Dead Sea salt water across the valley,” wrote a group of research collaborators in an article in The Conversation (archaeologist Phil Silvia, geophysicist Allen West, geologist Ted Bunch and space physicist Malcolm LeCompte). “Without crops, no one could live in the valley for up to 600 years, until the minimal rainfall in this desert-like climate washed the salt out of the fields.”
Read the team’s paper in Nature Scientific Reports
More information about the Tall el-Hammam excavation can be found at this website
Lead image caption: This is an artist’s depiction of a 10-kilometer (6-mile) diameter asteroid striking the Earth. Credit: Don Davis/Southwest Research Institute.