Cnet recently published a story about several objects that fell from the sky, turned into fireballs as they passed through the atmosphere, and then crashed into the scrub on the island of Chiloe off the coast of southern Chile, starting several fires. The story began to get interesting when Chile’s National Service of Geology and Mining ruled out the possibility that the objects were part of a meteor.
Rocks hit the Earth from space all the time. Most of the time, the meteors are small enough that they burn up in the atmosphere and create a nice light show. Sometimes, though, enough of a meteor survives that it hits the ground, creating craters and, in certain cases, causing property damage. The Planetary Science Institute notes that about 500 objects per year hit the Earth after entering the atmosphere from space.
Usually, meteors that reach the Earth are of interest, besides the locals, to scientists who are interested in studying space objects and treasure hunters interested in selling them as novelty items on eBay and elsewhere. From time to time, meteors can cause worldwide news, such as the one that exploded over Siberia in 1908, flattening eight million trees and killing uncounted reindeer with a force 185 times greater than the atomic bomb that destroyed Hiroshima. In 2013, another object exploded over the Urals, shattering glass and injuring 1200 people.
The most famous impact of all took place 65 million years ago and caused a worldwide firestorm and then a years-long “nuclear winter” that killed the dinosaurs. NASA has become increasingly concerned about a similar event destroying all human life on the planet.
However, if the Chiloe Island objects were not natural, what were they?
Naturally, the human imagination starts thinking about an alien spacecraft that suffered a mishap and crashed to Earth. Most people know of the story of the alien spaceship that allegedly crashed near Roswell, New Mexico.
The incident involved a “flying disk” that landed in the desert and was then, so the story goes, retrieved by the US military. Roswell has generated decades of conspiracy theories of aliens visiting the Earth and the government covering the “fact” up. The story has had an impact on popular culture, being the subject of numerous movies and TV shows, “The X-Files” being the most famous example.
However, the best guess of the geologists on the scene of the crash is that the objects were likely not alien in origin, but human-made space debris. Cnet reports:
“With meteorites ruled out, that would seem to indicate it was pieces of an old satellite or maybe a rocket booster that roasted bits of Chile. The geologists who investigated the scenes told TVN they’re performing a more detailed analysis of soil samples and will release their conclusions later in October.
“This could mean geologists found bits of metal that might indicate human-made space junk started the fire, but they’re double-checking what type of material they’ve found. It makes sense to ensure they haven’t collected some other sort of metal or perhaps even a new element created by a far-off alien civilization that likes to announce itself by torching bushes.”
Barring something unexpected, such as the discovery of exotic metals or perhaps the alien version of a black box, space debris makes the most sense as the cause of the Chiloe Incident. Humans have created hundreds of thousands of pieces of space junk since the space age began.
These range from tiny pieces of metal to spent satellites and boosters, causing a potential navigation hazard. On occasion, the International Space Station has to be moved to avoid a collision. NASA, other space agencies, and commercial companies have been mulling how to clean up the swarms of space debris before they start becoming a real problem for space travelers.
From time to time, space debris will enter the Earth’s atmosphere and will burn up safely. But just as with meteors, enough space junk can survive to hit the ground and potentially cause problems for people and property.
The most famous reentry of space debris happened when Skylab, the first American space station, hit the atmosphere in 1979. The event was marked with mixed humor, with commemorative t-shirts being sold, and great concerned out of fear that pieces of the orbiting lab might cause injury and property damage, but by a stroke of sheer luck, Skylab broke up over the Australian Outback and, so far as anyone knows, did not cause damage to human beings or property.