A Massive Meteor Hit Earth Last Year; Almost No One Noticed
A massive meteor explosion over the Bering Sea three months ago went completely unnoticed until just now, when scientists reviewed low-frequency acoustic wave data picked up by global recording stations. The 32-foot diameter meteor exploded on Dec. 18, releasing 173 kilotons of energy – about 10 times that of the atomic bomb dropped on Hiroshima.
This latest meteor explosion was the second largest impact in the past 30 years, coming in behind the Chelyabinsk meteor of 2013 which caused a number of injuries and was widely captured on video.
But unlike Chelyabinsk, this recent explosion took three months to be detected by a scientist studying infrasound data, which is inaudible to humans, but recorded by 16 monitoring stations around the world. The explosion is even being compared to the Tunguska event of 1908, during which a meteorite leveled an area of Siberia that included somewhere in the range of 80 million trees.
The explosion occurred in an incredibly remote area of the planet over an ocean where, luckily, no air traffic was passing through at that moment. But the fact that meteors this size with devastating potential, can enter the atmosphere almost undetected is a little unsettling.
While it wasn’t witnessed or officially recognized until now, footage from a Japanese weather satellite happened to capture an image of the explosion as it entered the atmosphere between Russia and Alaska.
Scientists often refer to a meteorite this size as a city-buster due to its potential to level an entire city, and bolides this size tend to enter our atmosphere a few times per century.
Reassuringly, most of the larger asteroids floating in our general vicinity have been mapped out and are regularly monitored by scientists at various observatories – even if we don’t necessarily have the means to deflect them if they were on a crash course with Earth.
But these mid-size rocks are particularly troubling, especially as man-made space debris can lead to collisions and changes in trajectory.
The technology and cataloging of 90 percent of all near-Earth asteroids larger than 450 feet in diameter is underway, but may take several decades. But these are only the rare nation-busters that would wipe out an entire country; mapping out all of the smaller city-busters is something that hasn’t really been considered, if it’s even possible.
Seems like it might be time someone builds a machine learning algorithm to do that for us.
For more on near-miss asteroids check out this episode of Beyond Belief with Dan Durda:
What's Sending These Mystery Signals From 4,000 Lightyears Away?
A mysterious repeating radio signal from space has been detected that scientists have not seen before. What or who is sending this signal?
Scientists have detected a radio signal from somewhere out in deep space some 4,000 light-years away.
The signal pulsed every 18 minutes and 18 seconds, for 30 to 60 seconds — every time, 18 minutes and 18 seconds. It did this for three months then it stopped. Scientists assume it is a naturally occurring rotating object that, like a lighthouse shining its beacon, will send what appears to be a repeating signal.
But Natasha Hurley-Walker, whose study into this repeating signal was recently published in the journal Nature told Vice, “[T]here are no models that produce such bright radio emission from two objects in orbit with each other, with such precision, and any that would produce any kind of radio waves would also produce X-ray emission, which we don’t see.”
Some think this might be coming from a highly magnetized star called a magnetar. So what does this all mean? Astronomer and Gaia News contributor Marc D’Antonio weighed in on the subject.
“Maybe this strange signal is some weird kind of magnetar that is rotating, but we’re not used to seeing it rotate every 18 minutes, that means a rather slow rotation. So, this is kind of weird, it’s something that doesn’t match any model that we know, and I think it takes us down a new research path to try to figure out just what it is we’re looking at,” D’Antonio said.