By Casey Frye, CCNN Writer
One of the most well-known comets is Halley’s Comet. It sails across Earth’s skies roughly every 76 years and is bright enough to be seen with the naked eye. According to Columbia University scientists, a deadly piece of the comet may have slammed into our planet 1,500 years ago, causing massive planetary chaos!
Researchers were examining ice in Greenland, which was formed sometime between A.D. 533-540. The analysis showed large amounts of dust from the atmosphere, including chemicals such as tin, which are more common on comets than they are on Earth. “I have all this extraterrestrial stuff in my ice core,” said study leader Dallas Abbott from Columbia University’s Lamont-Doherty Earth Observatory.
Interestingly enough, the chemicals seem to have been deposited in the Northern Hemisphere during the spring time, which coincides with the Eta Aquarid meteor shower – a stream of meteors trailing Comet Halley. “Of the two brightest apparitions of Comet Halley, one of them is in 530,” Abbott said. “Comets are normally these dirty snowballs, but when they’re breaking up or they’re shedding lots of debris, then that outer layer of dark stuff goes away, and so the comet looks brighter.”
Earth passes through these meteor showers at least twice a year, and according to the researchers, a mega piece of the comet likely crashed into our planet. This impact, and possibly another event such as a volcanic eruption, may have been responsible for cooling the planet by at least 5.4 degrees around 530 A.D. Drought and starvation would have followed the change in temperature, making mankind more vulnerable to disease and death. This weakness might have even caused millions to catch the Plague of Justinian – one of the first recorded instances of the Black Death in Europe. Named after the Eastern Roman Emperor Justinian I, the plague killed millions from A.D. 541-542.
Researchers don’t know how large the meteor was or where exactly it struck the Earth, but according to scientific estimates, it only needed to be 2,000 feet wide to explode in the atmosphere and spread dust around the globe.
Halley’s Comet is expected to return to Earth’s skies around 2061, but don’t start setting your doomsday clocks just yet. Even if it was once the cause of destructive planetary cooling, that was 1,500 years ago! So, it’s safe to say, such an event is truly rare.
Featured image courtesy of NASA.