Posted on 03/15/2022 7:59:46 AM PDT by Red Badger
A fireball over San Francisco Bay Area on 17 Oct 2012. (NASA/Robert P. Moreno Jr)
On 11 March 2022, at around 9:20 pm UTC, a small asteroid entered Earth's atmosphere.
This is not unusual. Space rocks enter Earth's atmosphere all the time. What makes this asteroid so amazing is that an astronomer spotted it before it made its rendezvous with atmospheric entry. It's named 2022 EB5, and it's only the fifth asteroid we've ever managed to spot prior to impact.
The object, thought to measure around two meters across (6.5 ft), was spotted by astronomer Krisztián Sárneczky of Konkoly Observatory's Piszkéstető Station in Hungary, at 7:24 pm UTC.
5th Earth impactor from Piszkéstető Obs: 2022 EB5 Yesterday at 19:24 UT an unknown moving objects of 17 mag was found by K. Sárneczky on images from 0.6-m Schmidt telescope. Acquired data 30 min later showed that it was going to collide with Earth in 2 hours time. pic.twitter.com/NdLUcF1MnM
— Stefan Kurti (@KurtiStefan) March 12, 2022 It entered Earth's atmosphere two hours later, at 9:22 pm UTC, over the Arctic Ocean just South-West of Norway's Jan Mayen island, at an entry speed of around 18 kilometers per second (11 mps).
Not long after that, infrasound instruments in Greenland and Norway picked up an explosion, likely from the object shattering in the sky before falling into the ocean.
According to those detections, the blast had a yield of about 2,000 tons of TNT.
Infrasound detection from 2022 EB5 impact off the coast of Iceland at I37NO between 2223-2227 UTC. Below is I18DK infrasound data in Greenland. Arrival near 2340 UTC. From this data yield is approximately 2-3 kT TNT. At 15 km/s, this is roughly 3-4 m diameter. @WesternU #2002EB5 pic.twitter.com/FYI9jn7zCb
— Peter Brown (@pgbrown) March 12, 2022 The previous four asteroids detected prior to impact were 2008 TC3, which was around 4 meters across and exploded with the energy of up to 2,100 tons of TNT; 2014 AA, at 3 meters and up to 1,000 tons of TNT; 2018 LA, at 3 meters and 400 tons of TNT; and 2019 MO at 6 meters and 6,000 tons of TNT.
Most objects of this type will explode as they fall through Earth's atmosphere, turning into what we call a bolide. Scientists think this occurs when air enters the object's body through small fractures in the meteor, causing a build-up of pressure as it flies through the atmosphere at high speed.
Fragments of the asteroid may fall to Earth, but anything left of 2022 EB5 after burning probably fell into the ocean. This, too, is normal: most of Earth's surface is covered by water, so it stands to reason that most space rocks will end up there.
Impact! When 2022 EB5 struck the Earth north of Iceland this morning, it became the 5th asteroid to be discovered prior to impacting Earth. pic.twitter.com/kYsQ40uuFq
— Tony Dunn (@tony873004) March 12, 2022 However, the discovery of 2022 EB5 is amazing for another reason.
The increasing number of asteroids detected prior to impact, as well as their decreasing size, bodes well for our hazardous asteroid detection capabilities. 2022 EB5 was never large enough to be considered hazardous, but if we can detect small, non-hazardous objects, that suggests our detection capabilities are getting better.
People in Norway or northern Iceland may have seen a brief flash light up their skies for a few seconds as the burning bolide streaked across the sky. If you were one of them, you can report your sighting to the International Meteor Organization here.
Asteroid - rock in space
Meteoroid - rock in atmosphere
Meteorite - rock on ground
I believe a meteoroid is a rock that has not yet entered our atmosphere. That would be a meteor.
Again, the distinction is not made with asteroids.
Correct
I’ve been on forums where I respond to someone, and then see a post that I immediately want to send a short quip to, and I get a “must wait 10 seconds to post again”. If I immediately try to post again, it will say, “must wait 8 seconds...” Etc.
If it’s rock going 11 miles/sec, the atmosphere is going to cause it to break up at high altitude.
A solid iron meteor might stay together long enough to reach the ground.
An asteroid smashing into San Francisco?
Missed it by this much, darn!
God always gives a warning shot................
Meteoroids are one meter or less in diameter. Asteroids are larger. A meteoroid becomes a meteorite when it impacts the earth.
...so Wikipedia tells me.
What’s the difference between a meteoroid and an asteroid?
A big meteoroid destroys dinosaurs.
asteroid just flies by earth.
If my calculations are correct, that thing was moving about 40,000 mph.
Atmospheric density drops off markedly with altitude, so its pretty tenuous for most of the trip, and at 11 mi/sec will meet up with, and make the entire journey through most of the atmospheric mass in the final one second.
The Earth's surface (and us) receive more protection from the random nature of all the millions of orbits (in three dimensions) and distances involved. Despite that, the Earth is and has been continually bombarded by mostly-water solar system debris for billions of years.
Composition is important, but so is mass. A carbonaceous chondrite that starts out about the size of a car will probably litter its way through the atmosphere, but there's a decent chance a piece the size of some kind of sports ball will reach the ground. Metallic chunks are less likely to break up on the way in.
Thanks IYAS9YAS, Erik Latranyi, and BradyLS.
Folks in Newfoundland took time-lapse photos of it’s passing and what it looked like on the streets. No one caught the actual asteroid, though. Pity. I’m sure it was spectacular.
Seems plausible...................
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