Sciency Words: The Tunguska Event

Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us all expand our scientific vocabularies together. Today’s term is:

THE TUNGUSKA EVENT

June 30, 1908, was a bad day to be a tree. At least, it was a bad day for a heck of a lot of trees in the middle of nowhere, Russia.

Something—there’s debate over what exactly is was—fell from space that day. It didn’t make it to the ground. Instead, it exploded midair above the Tunguska River.

According to human eyewitnesses, who were many miles away, the sky appeared to be split in two by fire. They heard a series of loud booms. The ground shook, and there was a sudden and intensely hot burst of wind so strong it apparently knocked people off their feet.

According to tree eyewitnesses… actually, we can’t ask the trees what they saw. They died. About 2,000 square kilometers (almost 800 square miles) of forest were scorched and flattened.

Scientific debate continues over what caused the Tunguska Event. It could have been an asteroid; however, asteroid debris can usually be identified by the presence of certain rare metals, such as iridium and osmium. These metals have not been found in the Tunguska region, at least not in quantities that would be atypical for Earth.

Another possibility (which makes the most sense to me) is that is was a comet. Comets are composed of lighter, more volatile chemicals like water. So when the Tunguska comet exploded, it would have been completely vaporized, leaving no debris.

The absurdly huge asteroid that killed the dinosaurs gets a lot of attention in popular culture, but asteroids (and comets) don’t have to be mass-extinction-sized to cause considerable damage. If the Tunguska Event had been the New York Event, there would be no more New York. And if something that big fell over the ocean, the resulting tsunamis could obliterate hundreds of miles of nearby coastlines.

Much like the Carrington Event of 1859, the Tunguska Event serves as a warning. Space is dangerous. Space is deadly. Earth can’t protect us from everything.