The glowing object was a bolide, fireballs that explode in a bright flash, according to experts. It streaked across Mexico’s predawn skies on Wednesday.
For a few brief moments on Wednesday, a bright fireball lit up the predawn skies near Mexico City. The display awed residents and online viewers alike as videos of the object quickly spread.
The glowing object was a bolide, according to The Associated Press. Bolides are fireballs that explode in a bright flash, often with visible fragmentation, according to the American Meteor Society.
Whereas a meteorite is a space rock that reaches the ground, a bolide is “just the luminous phenomenon” associated with the object’s atmospheric entry, said Jérôme Gattacceca, the editor of The Meteoritical Bulletin of the Meteoritical Society, an organization that records all known meteorites.
Meteors that are brighter in our sky than Venus are called “fireballs,” Dr. Gattacceca said. While meteors and fireballs are common, bolides are less so — though “still not rare,” he said.
This echoes what Guadalupe Cordero Tercero, a researcher at the UNAM Institute of Geophysics and head of the Mexican Meteor Network project, told UNAM Global Magazine.
It’s “estimated that every two and a half days an object at least one meter in diameter enters the Earth’s atmosphere,” Dr. Cordero Tercero said, according to the magazine. However most of these objects fall into the ocean or uninhabited areas, so they often go unnoticed.
Denton Ebel, a curator of meteorites at the American Museum of Natural History in Manhattan, said that while he had seen only some footage of the fireball and heard stories, “it sounds really exciting.”
Meteors are “not as uncommon as many people think,” Dr. Ebel said, but they are being reported more frequently because of fireball networks, which are cameras parked atop buildings that capture the objects as they enter the atmosphere.
UNAM Global Magazine also reported that the fireball roared after streaking across the dark sky. A sonic boom is associated with its breaking apart, Dr. Gattacceca said.
“This noise is usually a good indicator that the object fragmented at relatively low altitude and that meteorites actually reached the ground,” he added.
The rumbling can sound almost like a freight train, Dr. Ebel said.
Meteors are all created by space rocks hitting the atmosphere at high speed, Dr. Gattacceca said, and most of these space rocks originate from the asteroid belt.
Their high velocity means that small rocks, even the ones as small as a walnut, will “generate a fireball because of its elevated speed,” Dr. Gattacceca said.
The object’s dazzling display caught the attention of many of the more than 22 million people who live in Mexico City, who had nothing to fear.
“Nobody has ever been killed by a falling meteorite in historical times,” Dr. Gattacceca said, adding, “So, not dangerous.”
Source: Elections - nytimes.com
