A Huge Meteor Exploded Over Earth
But nobody noticed! This was all because, as Forbes reported, of where it burnt out in the sky, and obviously the size of it!!
The largest meteor impact on Earth since the Chelyabinsk incident is chewing up headlines, despite the fact that it happened weeks ago and no-one noticed.
NASA’s Fireballs and Bolides Report page noted the impact of a largeish space rock on February 6 over the ocean off the coast of Brazil. The meteor was probably around five to seven metres wide, about the size of a living room as colourfully noted by Bad Astronomer Phil Plait, making it the biggest to hit since the one over the Russian city of Chelyabinsk that shattered glass and injured hundreds of people.
But since it happened over the sea, no-one noticed this one. In fact, even if it had hit over a populated area, it probably wouldn’t have done any more than rattle a few windows and give folks some great pictures and a smashing anecdote.
The meteor was picked up by NASA astronomer Ron Baalkein a tweet and then analysed by Bad Astronomer Phil Plait in a post for Slate. As Plait points out, the energy released by the blast from this space rock was roughly equivalent to the detonation of 13,000 tons of TNT. That sounds like a lot, but not when you know that Chelyabinsk was more like the equivalent of 500,000 tons of TNT.
More than a thousand people were injured by the explosion over Chelyabinsk three years ago, most from flying glass broken by the blast. The fireball over the Atlantic burnt up around 30km over the ocean and a thousand kilometres off the coast of Brazil and was unlikely to have been seen by anyone.
NASA estimates that around 30 small space rocks burn up in Earth’s atmosphere every year (these are called “impacts” even though they usually don’t make it through for a landing). The vast majority of these are unnoticed by human observers because they enter the atmosphere over the 70 per cent of our planet that’s water. Even if a meteor does happen to hit over land, Earth is actually relatively sparsely populated, so the chances of a hit like Chelyabinsk are quite low.
With no-one around to see these impacts, they’re picked up by military instruments monitoring for atmospheric explosions (for obvious reasons) like satellites, seismic monitors and atmospheric microphones. It’s likely that the various world militaries monitoring our skies don’t always pass on the information when they spot a meteor hit, but only when doing so doesn’t give away their technology and capabilities, so there may be many more small impacts than scientists know about.
NASA’s Fireballs and Bolides page lists many hits a month, but most of them have a total impact energy of under one kT, compared to 13 for the February 6 impact and 440 for the Chelyabinsk meteor.
Are you interested in what goes on above our heads? Way above our heads, and for many years over our heads, Space has fascinated many! Here at The Sheffield College we are just as fascinated too. We offer fantastic Science courses and we think you should check them out now!