I have a Birdweather puck (https://birdweather.com) that listens for birds in our backyard in suburban Boston. It also measures sound pressure level (30 second sample rate).
Our puck showed a 90.8dB sound level compared to a 55dB baseline.
We thought a tree had hit the house because of the double boom. That was a repeated observation across all the local social media groups. The local UPS driver, who was outside at the time, said he "felt it in his chest".
Interesting this also happened in South Carolina and Ohio within the past few months.
Feels like a proper movie that political boundaries like state lines would be significant for all concerned. One meteor for Rhode Island, one for Texas... Any questions? (Asks the alien overlord of his minions in his crisp British accent)
> Interesting this also happened in South Carolina and Ohio within the past few months.
Not that interesting, apparently this scale of meteor happens on average multiple times a year, just not usually over such an urban area.
The 2013 Chelyabinsk meteor (1) was larger and caused ground damage and injuries from e.g. flying glass from broken windows.
> Sounds like the beginning of an alien invasion movie. Sleeper ships buried themselves into every state.
Based on the last Alien invasion book that I read (2), it would rather start with air bursting the bioweapons, spreading the plagues to weaken us. Which ah, also fits this incident.
Okay that thing is cool. I made my own a while back with Pi 4 running https://www.birdweather.com/birdnetpi and I made my own fancy microphones with solder and a fuzzy cover. Worked amazingly well.
I’m around 8 miles west of Boston. I was playing on the floor with my daughter and had my ear to the ground- suddenly heard all of the windows shaking, the floor rumbled and an explosion louder than I’ve ever heard before.
Honestly what spooked me the most was seeing nothing on the horizon to help explain it! I am shocked and grateful it didn’t break any windows or cause further damage.
I'm in Watertown on a busy road and was near an open window when it exploded. I thought a truck had slammed into my building and was baffled when I saw everything was fine.
It's just earlier this week we have an HN front-page news on the sophisticated Rubin telescope [1].
According to its Wikipedia entry, "Rubin is expected to catalog millions of supernovae, more than five million asteroids (including ~100,000 near-Earth objects), and image approximately 17 billion stars and 20 billion galaxies." [2]
I guess this this reported meteor is the one that got away, or perhaps it's beyond its scope of monitoring the Southern sky. But even if it's monitoring the Northern hemisphere it will most probably going to miss it due to the puny size of the meteor, more like a small tent instead of a skyscrapper.
>The meteor was about five feet wide, according to the space agency, with a mass of 5.6 metric tons (that's about the weight of a large elephant.)
[1] Rubin Tracks Skyscraper-Size Asteroids and Failed Supernovas:
The day was somewhat stormy. I was in my kitchen in my north-suburban-Boston house, when I suddenly heard a BOOM. I thought it was a very large branch falling on my house, so I ran outside to check out the roof. Saw nothing, and only later heard about the meteor.
We had a meteor 15 years ago or so. I happened to open the side door just as it was overhead. It looked like late afternoon by the light, but it was long after dark by the clock. I had just a moment to question both my watch and my sanity before it went dark again.
A few years ago I heard a bang and my whole house shook. My roommate and I both thought a car had hit the house. Never did find out what caused it, I think it must have been a sonic boom, most likely a military aircraft. The way it shook the house though, it was hard to believe that something didn't hit the building.
That’s what a small earthquake with a nearby epicenter feels like. The first time it happened to me it felt like a tree hitting the house. (“Small” is circa 3.0 magnitude.)
The devastation we are seeing is unparalleled. Judging from early estimates - millions dead. A state in ruins. The meteor was shot out of orbit by Bug Plasma that derived from Klendathu, the Arachnids home planet. Nothing lives in what was once called the Turkey Paradise. Massachusetts…has been wiped off the Earth. The US Congress met moments ago and voted unanimously for mobilization to destroy the Arachnid threat.
Apparently it fell into the water. Maybe it can be recovered and made into the second coolest rock exhibit in Massachusetts (first is Plymouth Rock obviously).
This time Malcolm X’s line about “Plymouth Rock landed on us” would apply to everyone. And Plymouth Rock is very much not cool. It’s the anticlimax of a million school field trips.
Plymouth Rock is one of the greatest pranks ever played. There‘s so much history in the region—the story of the founding of this massive country—and the capstone is this “world’s largest ball of twine” level attraction. Brilliant.
I was at a beachhouse north of Boston and I thought someone fell out of bed or dropped something really heavy upstairs. It was loud and the whole house shook. All of us were scouring the internet for like an hour, finding absolutely nothing "official" or any mention of it on news sites- just tons of subreddits and other social media blowing up all over the Northeast wondering what the heck it was.
I heard it in Boston and with initial reports saying it broke up over Cape Cod I was kind of surprised and just assumed a very big kaboom. There was a strong storm with 30knt wind from the North at the time. It makes a lot more sense that the shockwave was produced North of here at the NH border and travelled with the wind and the remnants falling East of here in the Bay.
Everyone knew it didn't hit Boston when the boom wasn't followed by the sound of keyboards every government office rushing to get rid of all the rules they never wanted in the first place.
It's the most common unit for describing the explosive yield of a nuclear weapon. So, it's a lot smaller than the bombs dropped on Japan in WWII, but a lot bigger than a Davy Crockett. That's a sort-of-useful frame of reference.
The only other things I can think of that would create a similar kind of blast are a volcanic eruption or something like that fertilizer explosion in Beirut in 2020 (~1100 tons TNT equivalent.)
PSA: meteors have nothing to do with explosions. The shockwave comes from meteor's movement alone, the parts never move apart with any speed comparable to their common forward motion.
A breakup will increase surface area and therefore kinetic energy to shockwave transfer efficiency, still not an explosion.
PSA: The word "explosion" has multiple definitions, plenty of which are actually quite reasonable to apply to meteors! It can refer to the sound alone, for example. The people reporting an explosion in Massachusetts were not incorrect!
It would however, be incorrect to claim that the meteor had noting to do with explosions.
No? There is no violent expansion or bursting, even if the sound is similar. It is as much an explosion as a supersonic jet passing by, and that is not much.
The term makes people think atmospheric heating causes an actual steam explosion and that's the source of shockwave, which can't be further from truth.
Meteor Chelyabinsk suffered catastrophic fragmentation, a rapid, violent release of energy accompanied by a pressure wave with debris, which would satisfy the definition of an explosion (an in fact the energy released was equivalent to 400-500 kilotons of TNT.)
Do you not consider Tunguska an explosion? It’s always described as such. IIRC, it never even hit the ground. Sure, a lot of the damage was caused by the air being compressed from above, but it created an air burst, which would have released a lot of energy in every direction.
The Wikipedia article on "meteor air burst" has an explanation that basically matches yours, although they do use the word "explosion" to describe it. Which makes sense to me: whatever one chooses to call it, it's a nearly instantaneous spontaneous disassembly that is very bright, very hot, and very loud.
The speed scale for disassembly is nowhere near the forward speed; you never get anywhere close to 45 degree debris divergence angle. It's also, again, not the disassembly that causes it to be bright, hot and loud. Wikipedians can also be wrong.
The meteors made only of iron alloy and/or silicate rocks do not explode, but they may fragment into many smaller bodies.
The meteors that contain great amounts of volatile substances (water, carbon compounds and sulfur compounds) may explode if the interior becomes hot enough to convert the volatiles into gases. When such a meteor rich in volatiles fragments, some of the fragments may explode, while others may reach the surface of the Earth intact.
jojobas and NASA's statements aren't contradictory.
NASA states: "the fragmentation of the fireball unleashes large amounts of energy, which also generates a pressure wave that can produce a very loud boom, even shaking houses."
Fragmentation of a fireball, whilst not explosive itself (the particles needn't diverge at a supersonic relative velocity) are nonetheless part of a supersonic / hypersonic particle field relative to the atmosphere they are passing through. Expanding the diameter of that particle field will increase the size of the resultant shockwave, whether the particle separation itself is "explosive" or not.
The "explosion" then is of the deceleration (aerobraking) shockwave, not the bolide separation. But the bolide separation increases the intensity of the shockwave, with more (and lighter) particles interacting with the atmosphere over a shorter distance than an intact, small-diameter bolide would.
Some of this depends on what definition of "explosion" one chooses, or whether people are intending an explosion specifically, or an explosive sound (sonic boom). That's confounded by bolide separation, the bright light emitted on entry, and sonic effects, all of which are semantically associated with other explosive events. Language is a consensus phenomenon.
I'd tend to call the event an explosion, though not in the expanding particle field sense.
Your statement is not supported by, and is somewhat at odds with, physics. As described in this source, observed terminal brightening/"burst" of a bolide is tied to the body's material behavior (fragmentation, rapid lateral expansion, ablation), and not to a free-standing "deceleration shockwave" that exists independently of the body breaking up.
Some meteors really explode, because water and other volatile substances contained in them transform from solids into high temperature gases that expand quickly and cause the explosion of the body.
This is the same like how many kinds of water containing things, e.g. raw meat, eggs, fruits, can explode in a microwave oven if the microwave power is too high.
The meteor bodies belong to several classes of chemical compositions. Some of them contain very little volatiles, and they are made either of iron alloy or of silicate rocks or of a mixture of iron alloy and silicate rocks. These do not explode, at most they fragment into many smaller bodies.
Other classes contain great amounts of volatiles, e.g. water, organic compounds and sulfur compounds, and they frequently explode, depending on their size, shape and trajectory, i.e. if there is enough time for the interior to be heated to high temperatures, causing the phase change of the volatiles to gases.
I didn't state that the shockwave is independent of whether or not the body breaks up, I wrote, emphasised, "Expanding the diameter of that particle field will increase the size of the resultant shockwave, whether the particle separation itself is "explosive" or not."
Which your article (partially read, sorry, incredibly shitty reader) largely substantiates, largely in the itemised list in section 2.2. Pancaking of a bolide through fragmentation increases frontal area, has multiple points of mass interacting with the atmosphere over a larger area and with less mass at each point, and the (undiscussed) light-emission mechanism which itself largely derives from compressive heating and ionisation of the atmosphere (rather than friction against the atmosphere or heating of bolide particles themselves). Increasing the number, and surface areas, of particles increases the region and intensity of this effect.
As your source discusses, most fragmentation is a result of mechanical rather than thermal forcing of the bolide.
You are correct in class 9 physics book in India we have a mention of supersonic planes producing a sonic "boom" so the suprsonic planes don't themselves explode but their fast movement makes the air produce the boom. So you were correct as far as I can tell. But meteors do get smaller and smaller due to extreme friction from air and they do break into several pieces so that can also add to the sound.
Without disagreeing with you, what should the event be called?
Breakup, impact, fly-by? all those could be incorrect if all you know is a space object entered the atmosphere, made a sound, and flashed some light. What do you call that? Especially because you don't automatically know if it impacted the surface. At which point it becomes a meteorite, so even calling it a meteor is not fully correct. Or do you get ultra technical and say that when it made the sound and flash, it had not yet reached the ground, therefore it was a meteor at the time?
https://b612.ai/
The ".ai" stands for "Asteroid Institute." It was started by two former astronauts, Ed Lu and Rusty Schweickart.
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