Date:13 December 2017
Earth’s atmosphere is even stronger than previously thought. According to new research out of Purdue University, atmospheric air particles penetrate the porous interiors of meteors as they hurtle towards the planet.
By David Grossman
Once inside Earth’s atmosphere, the devilish air particles create pockets of high pressure that eventually cause the space rocks to explode from the inside.
“There’s more going on than what had been thought before,” says Jay Melosh, a geophysicist at Purdue in a statement. “Bottom line is that the atmosphere is a better screen against small impacts than we had thought.”
NASA estimates that 48.5 tons (44,000 kilograms) of meteoric material falls on our planet every day. Meteors are essentially piles of rubble smashed together, air particles infiltrate every pore and fracture they can.
Melosh and his colleagues studied the largest object to enter Earth’s atmosphere in over a hundred years. It is the 2013 Chelyabinsk meteor that exploded over western Russia. It exploded with 26 to 33 times as much energy as the Hiroshima atomic bomb. Running Chelyabinsk through a simulator that accounted for porosity made all the difference in understanding why it exploded the way it did.
“I’ve been looking for something like this for a while,” Melosh said in another press statement. “Most of the computer codes we use for simulating impacts can tolerate multiple materials in a cell, but they average everything together. Different materials in the cell use their individual identity, which is not appropriate for this kind of calculation.”
A renegade asteroid might someday overwhelm the Earth’s natural defenses. However, NASA is working on taking proactive measures against the threat. As for now, once they crash they mainly exist as phenomenally expensive rocks.
From: PM USA