Are there really more BIG fireball class meteors than there were in the past?

So with all the talk of fireballs since Chelyabinsk which was just over a year ago now, I thought it's worth putting together a thread that attempts to put this phenomena into perspective. I came across a link in another ATS member's post which in turn led me to this page which has a collection of reports of historic bolides (a bolide is a very bright/large fireball) that occurred over Britain. There is also a mention of reports collected from around the world:

Those evanescent phenomena known as ‘shooting stars’ superficially resembled bolides, but the latter were larger, brighter, and rarer. They were often as bright as the Moon, and sometimes exceeded even the Sun in brilliance. The paths of these fireballs were hundreds, occasionally thousands, of miles long; like the ‘terrific meteor’ of 5th September, 1868, which, as R.S. Ball said, “broke into visibility at a great height above the Black Sea, and had not expended its stupendous energy until it passed over the smiling vineyards of France.” Some scientists believed that there was a spectrum of bolides, with shooting stars at one end and the monstrous apparition of 1868 at the other, whilst others considered the phenomena to be distinct. The second opinion proved to be correct. ’Shooting stars’ were the dust of comets, whilst bolides originated as asteroidal fragments. Shooting stars were certainly far more common than fireballs. The former could be seen on any clear night,whilst a major bolide was a once in a lifetime experience. During meteor showers, shooting stars fell in their thousands, but a bolide merited a letter to a scientific journal. A record of bolides gathered from all over the world from mid-1877 to mid-1878 produced a total of only 86. (Of course, many went unreported). A limited area such as the British Isles, despite being thronged with eager observers, recorded such things even less frequently, However, as bolides took no note of terrestrial geography, a brilliant example was as likely to be seen there as anywhere else.

Bold text added by myself

Note that ordinary fireballs are not recorded in the mid-1877 to mid-1878 study, where as today ordinary fireballs and bolides are usually lumped together.

Just out of interest, can anyone here show me 86+ reports of BOLIDES from the past year?



The great bolide of June 20th, 1866 hurtles over Kent before exploding above the coast of France, 10.45 a.m.



Here is a selection of those reports - please visit the link above for more:

1719 March 19 (O.S.)
At about 8 p.m., London was suddenly illuminated by a light almost as bright as the Sun. The stars and the waxing Moon were blotted out, and candles gave no light. A great fiery body, estimated to be over a mile in diameter, raced over southern England at 21,000 miles an hour before exploding thirty miles above the English Channel. At Stoulton in Worcestershire, about two minutes after the meteor passed, “a great howling noise (was heard) in the air”, and about five minutes after, “such a crack...as could not be made by the largest cannon.” The detonation shook the windows and doors of houses, and at Tiverton a looking-glass fell out of its frame and was broken. It is fortunate that the colossal energy of this meteor (which was a classic ‘aerolitic fireball’) was expended in the Earth’s atmosphere with no more effect than this.

1737 December 5
Dr. Thomas Short described a meteor ‘like a great ball of fire’ which burst over Kilkenny in Ireland. The explosion “shook a great part of the Island, and set the whole Hemisphere on Fire, which burnt most furiously, till all the Sulphureous Matter was spent.” Dr. Short held to the pre-Aigle view that bolides were entirely insubstantial manifestations created in the upper atmosphere.

1850 February 11
A fragment of interplanetary debris entered the atmosphere about 84 miles above Warwickshire at 10.45 p.m. It became a fiery globe a third of a mile across, with a tail several miles long; a few moments later the body exploded 19 miles over Biggleswade in Berkshire. In Oxfordshire, the detonation shook houses. A scattering of luminous remnants descended to within ten miles of the earth. Near Aylesbury, the meteor appeared as “a great mass of fire darting across the sky from west to east: a report like thunder followed about two or three minutes after the extinction.”

1866 June 20
“One of the largest class of bolides’ appeared about 10.45 a.m., in daylight, and was seen from Kent, Sussex, Boulogne, Lille, and Delft in Holland. From Penshurst in Kent, an observer (Mr. Naysmyth) described the meteor as “a bright red comet-shaped object rapidly moving across the clear blue sky...It is impossible to convey...the impression left by the appearance of this mysterious object, majestically traversing the clear blue sky during brilliant sunshine.” At Boulogne, the concussion of the detonating bolide sent alarmed persons running into the streets, where they saw the smoky train of the disintegrated meteor hanging in the sky.

1868 October 7
Once more nocturnal London - in fact the whole of south-east England and northern France - was illuminated by the light of a bolide. One observer said that everything in St. Paul’s Churchyard was suddenly “as clear as day, the cathedral...standing out in bold relief against a brilliant sky, the lights in the gas-lamps being for the time invisible.” From the suburb of Wimbledon the bolide was seen as “a red ball emitting bright sparks, and having a flaming tail of great length.” The bolide exploded somewhere between the Channel and Paris, at least sixty miles up. There were rumours of meteorite falls in various parts of France, but nothing definite was found.

Aerolitic fireballs may explode in the atmosphere and produce a shower of meteorites, but these fall under the influence of gravity for miles, and those who see the meteor rarely witness the descent to earth of the meteorite which created it. Most meteorite falls are unwitnessed and unfound, The ones that are seen usually take their observers by surprise.

1813 September 10
The morning was fine but sultry in County Limerick, Ireland, until at about 9 o’clock a solitary cloud appeared in the east. Soon after, strange sounds reverberated down from the sky. Eleven detonations, like the ‘discharge of heavy artillery’ seemed to emanate from the cloud; then ‘a considerable noise (like) the beating of a large drum’ followed by ‘an uproar’ resembling mass musket fire. At last a hissing noise was heard, and several bodies fell from a darkening sky, ‘which directed their course with great velocity in a horizontal direction towards the west.’ One object was seen to fall to earth near Pobuck’s Well; it was immediately dug up, still warm, and having a sulphurous smell. It weighed about 17 pounds. Two other large stones (and several small ones) were found a few days later; one weighed 24 pounds and the other 65 pounds.

METEOR Bolides over Britain

Now keep in mind Britain is a small place, and these are reports of very large fireballs, in some cases likely on par with Chelyabinsk.

This phenomena is nothing new, and it's certain that if anything there were periods in the past when there were more fireballs and bolides than today. It may well be true that there are more people reporting fireballs now than in recent years, but the average number of individual reports per event has also gone up, suggesting that rather than more fireballs, it could well be that there are more people watching and reporting fireballs as well as other factors such as increased ease of reporting events/better comms./more and better cameras/increased public awareness.

It might also turn out to be true that we have had a few better than average years for fireballs in a row, but so what? Like many natural systems there are bound to be fluctuations from year to year, and due to my past experience of this field it seems to me that people touting an increase in fireball rates are tending to misinterpret the data because they do not take factors such as those mentioned in the paragraph above and are thus wildly over exaggerating the fluctuations.


Before anyone comes here with the almost perquisite "move along, nothing to see here" line, let me just say that ever since I first became interested in the subject (1998) I have tried to raise awareness. Whilst bolides are usually harmless, there is a potential for larger bolides to cause significant localized damage and loss of life if one were to detonate directly above a city. With that said, the likelihood of something like that occurring is very low, and it has always been low, so there's no point loosing any sleep over it.


Related links:
AMS Fireball Stats Analysis released
Asteroids, comets threaten humanity: protection system is much-needed
It's Fireball Season!
The American Meteor Society Fireball FAQs
Wikipedia - Chelyabinsk meteor
Chelyabinsk one year later

Recent noteworthy fireballs:
Argentina-18 February 2014 - suspected bolide airburst shakes homes
UK/Europe-15 February 2014 - fireball caught on multiple cameras

Hey Fireball, with all due respect, I disagree. I think you are very wrong on the idea that these fireballs are ‘normal,’ so much so that I’m not quite sure what agenda you have. I, myself have been studying this phenomenon for more than a year and I am convinced that fireballs have definitely increased in a big, big way, almost to the point of several of these bolides every passing day. Many of them are spotted and reports have been made. Many are felt as there have been daily reports somewhere in the world of loud booms that shake and rattle homes, some with light flashes just prior to the explosion. Some of these may even be meteors, but we just don’t know.

You show some historical records as your evidence that these fireballs are nothing new, but at that time, the 1700 and 1800’s, there was absolutely no light pollution to interfere with a clear night, so yet, the chances per capita of seeing fireballs was greater, but at the same time, there are no photographic or video evidence of what people saw. We only have their individual eyewitness accounts to just how dramatic and brilliant the fireball actually was. Without light pollution, I’m sure a fireball may have appeared much brighter at that time.

Also, this handful of major fireballs you show is stretched out over centuries. Today, we’ve had more of these major fireballs documented in just one year…in Britian alone.

Major fireballs are happening every day throughout the planet. Sometimes they can even be coined as an ‘outbreak’ such as four different fireballs over Japan last month in one day, one of them was even a dramatic day time fireball caught on camera. A simple You Tube search will find these fireballs.

In January, the U.S. saw a couple of ‘fireball outbreaks’ as well.

I find it hard to believe that anyone can claim these fireballs are not on the increase, especially one who ‘watches.’ Well, I guess so, I watch and I still haven’t been fortunate enough to see one either and this is a year later since our last discussions on this matter. Trust me, I’ve been watching. My wife actually saw two though in this last year. She saw one in Florida two months ago and she also saw one of the ones that made news headlines last fall that streaked north across TN, KY, OH, IN, MI. She was in central Wisconsin and saw it. She told me about it and after we checked it out, it was the same time as the reports started coming in and in the same direction that fireball followed. Good for her.

Anyways, I expect that at the rate these fireballs are increasing, I’ll be seeing them soon to right along with many other unsuspecting folks.

Here is a quote from a story but I won’t sight the source because I’m not sure if that one is allowed by ATS moderators.

So many new comets were discovered last year that astronomers named 2013 the 'Year of the Comet'. Less popularized was the noticeable increase in fireball meteors observed in the Earth's atmosphere. Another year has passed and fireballs are still raining down like never before, with their rate apparently increasing exponentially.
has been cataloguing fireball events since 2002, and a couple of other websites have sprung up since then, but in general the lack of record-keeping and media coverage of this phenomenon is shocking, especially given how extraordinary the phenomenon is (or rather, was - apparently it's 'normal' now!) and whatever it may portend for civilization, sometime in the future, if not immediately.
One relatively new resource is the American Meteor Society’s ‘Fireball Logs', a database where eyewitnesses have been submitting reports of fireball events in the U.S. The AMS does subsequent checks to verify events with the All-Sky Fireball Camera Network set up by NASA's Meteoroid Environment Office (MEO) and other observation networks. Their stats are remarkable, yet they do fit with what we've noticed in recent years: the numbers just keep going up and up, and at an ever increasing rate!
Using the AMS data, which begins in 2005, I've created the following tables to give readers a visual for what's going on. Check this out:



The table below shows the number of fireball reports submitted to AMS between the years 2005 and 2013.



You say fireballs are very common but I disagree. Even observers from the All-Sky Camera Network would disagree. In an article from WayneIndependent.com about a fireball flash captured on camera in early 2013, a Thomas Cupillari observes the night sky through the Keystone College Observatory where one of these All-Sky cameras is set up. He said that it’s very unusual for fireballs to be so bright and stay so long. He said that only once he saw a fireball that stayed bright for more than 5 seconds. This is a person who studies the phenomenon every night.

The all sky camera is a fish eye lens that is pointed straight up into the air and can see 360 degrees around. The camera is in a network with Sandia National Laboratory through New Mexico State University. They are set up at various locations so common events that overlap can be tracked.
"The information from the cameras allows the laboratory to track where it came from, how high it was, and more," Cupillari explained. "It helps separate nature from manmade events."
The nearest location to the observatory is 80 miles south in Ottsville, which overlaps coverage.
"Regular meteors can be seen on clear nights and sometimes you can see several in one night, but fireballs aren't very common," Cupillari said. "One night our camera picked up 32 meteors and none of them were fireballs."

"Flash in the Sky" is a meteor

Notice how he states in the article that fireballs are not common. Thirty meteors in one night and not one of them was a fireball. If you look up all the sightings that have been occurring world wide over the past two years at the AMS site, you’ll see comments like this one quite often.

Kai L. of Livermore commented on the website, "I have done a considerable amount of stargazing in my 41 years on this earth and I have never seen anything this bright in the sky (besides the sun and the moon). I was completely stunned.”

I am 42 years old and this is exactly what my response would be if I were fortunate enough to witness one of these events. I have yet to witness something of this caliber other than the usual shooting star. At this increasing rate, I have no doubt in my mind that I will become one of these witnesses soon.

Let me chime in firstly we got to see why this sudden increase of reported sightings are happen..

1990 - only a phone to report sighting on depending how many people can be bothered reporting it.

1999 - Internet and phone to report sighting on depending how many people can be bothered reporting it.

2014 - internet, phone and phone app. The phone app would be increasing these sightings as more people find it easier to report it this way.

You see where I am coming from. as technology progressed so did the sightings after it made it easier to report them.

We aren't seeing a increase we are just aware of occurrences now due to more reports being made.

Do like i did check it out for yourself

Feb 08/2014

Nov 09 2013

Rez, likewise, with all due respect...

Rezlooper
Hey Fireball, with all due respect, I disagree. I think you are very wrong on the idea that these fireballs are ‘normal,’ so much so that I’m not quite sure what agenda you have.

I have no other agenda other that what I stated - to attempt to put the phenomena into historical context. There is no argument that there are many fireballs about - I just have not seen any convincing evidence that there are more now than in previous years.

Rezlooper
I, myself have been studying this phenomenon for more than a year and I am convinced that fireballs have definitely increased in a big, big way, almost to the point of several of these bolides every passing day. Many of them are spotted and reports have been made. Many are felt as there have been daily reports somewhere in the world of loud booms that shake and rattle homes, some with light flashes just prior to the explosion. Some of these may even be meteors, but we just don’t know.

Well, I don't want to get into a pissing contest, but one year is not a long time, and certainly not long enough to get a bit of perspective of this subject. I would argue that 15+ years studying this phenomena gives me a better overall picture - but there are people who have been involved in this subject for many decades who also share the same view as me. Should we ignore all this experience, and if so, why should we give more weight to your view on the subject?

Rezlooper
You show some historical records as your evidence that these fireballs are nothing new, but at that time, the 1700 and 1800’s, there was absolutely no light pollution to interfere with a clear night, so yet, the chances per capita of seeing fireballs was greater, but at the same time, there are no photographic or video evidence of what people saw. We only have their individual eyewitness accounts to just how dramatic and brilliant the fireball actually was. Without light pollution, I’m sure a fireball may have appeared much brighter at that time.

Light pollution has very little to do with it. It certainly would affect observations of meteors, and possibly might make it a little harder to observe border-line fireballs, but a bolide (the only type of fireball that was looked at in this study) is at the very least defined as a fireball that is significantly brighter than a full moon.

Even in the most light polluted locations it's easily possible to observe Venus (magnitude -4.5) on a clear night. A fireball (when observed high in the sky) is defined as a meteor of at least the brightness of Venus, so the majority of fireballs could easily be observed under heavily light polluted sky.

Something as big and bright as the Moon (magnitude -12) stands out like a sore thumb in even the most light polluted sky. Even in broad daylight the Moon is easy to see, and you can't get much more light polluted than that! BUT a bolide is still brighter at a MINIMUM of magnitude -14. Each more negative step in magnitude is an increase in brightness of 2.5x, so "-13" is 2.5 x as bright as "-12" and "-14" is 2.5 times brighter than "-13".

Basically the argument that light pollution has any significant on observation of bolides is moot. Even the dimmest bolides would be easily observable in daylight, and a significant portion rival the Sun (magnitude -26 about 400,000 times brighter than mean full moon) for brightness.

What would have had an effect on the number of events reported, and likely a very significant effect is that back then the world had 1/10 of the population it has today, and much larger areas of extremely sparsely populated (or unpopulated) wilderness, so that alone would ensure that many more large events went unnoticed then than go unnoticed today.

Rezlooper
Also, this handful of major fireballs you show is stretched out over centuries. Today, we’ve had more of these major fireballs documented in just one year…in Britian alone.

It's hardly surprising that there would be more major fireballs documented today - there are more people now, and most people now are well enough educated to understand when they are looking at a fireball. That is not to mention that communications have improved hugely since than.

So could you provide a list of all the major (big enough to cause sonic booms or determined to be significantly brighter than the Moon) fireballs that occurred over the course of a year over Britain? Even 2 or 3?

Rezlooper
Major fireballs are happening every day throughout the planet. Sometimes they can even be coined as an ‘outbreak’ such as four different fireballs over Japan last month in one day, one of them was even a dramatic day time fireball caught on camera.

Irrelevant, unless you can show that it was part of a trend, and not just a coincidence. Where does it say that fireballs have to occur at regular time spacings?

Rezlooper
I find it hard to believe that anyone can claim these fireballs are not on the increase, especially one who ‘watches.’ Well, I guess so, I watch and I still haven’t been fortunate enough to see one either and this is a year later since our last discussions on this matter. Trust me, I’ve been watching. My wife actually saw two though in this last year. She saw one in Florida two months ago and she also saw one of the ones that made news headlines last fall that streaked north across TN, KY, OH, IN, MI. She was in central Wisconsin and saw it. She told me about it and after we checked it out, it was the same time as the reports started coming in and in the same direction that fireball followed. Good for her.

Your wife was certainly fortunate to see two fireballs... but she is not the first to do so, and won't be the last. Luck will play it's part, but so does the way you live your life (if you tend to be outdoors a lot and/or look up more than most).

I think that you are missing the point though. There are so many variables in human behavior that trying glean useful data even from 10's of thousands of people's RANDOM observations (let alone one or two people) is impossible.

As I've said in the past, the only way to get definitive answers is monitor the sky 24/7, over a wide area, and over a few years (preferably decades).

Rezlooper
Anyways, I expect that at the rate these fireballs are increasing, I’ll be seeing them soon to right along with many other unsuspecting folks.

Keep your eyes open as well as spending more time outdoors, and sooner or later you will see one irrespective of fluctuations in frequency. When I say "one" I mean a fireball by technical definition, ie any meteor brighter than Venus. Three or four hours observing one of our annual meteor showers like the Perseids or Geminids on it's peak night from a reasonably good location (with fairly unobstructed views of the sky) and a clear sky is virtually certain to net you a fireball class meteor belonging to the meteor shower you are observing.

You are not any more likely to see a bolide type fireball than on any other clear night (or day) however since most are caused by asteroidal material and are random in occurrence unlike most fireballs seen during the annual meteor showers that are (mostly) cometary in origin. It is an important distinction to make, since we know that the kind of big and relatively deeply penetrating (into the atmosphere) fireballs (AKA "bolides") are 99 times out of 100 (if not more) caused by asteroids/fragments of asteroids entering the atmosphere.

You or I could easily go our whole lives without seeing a true bolide, although you can improve your chances a bit by being outdoors and looking up more often, but it only takes a moment of taking your eye off the sky to miss one! It's basically pure luck if you get to see one unless you take up living outdoors 24/7.

Rezlooper
Here is a quote from a story but I won’t sight the source because I’m not sure if that one is allowed by ATS moderators.

So many new comets were discovered last year that astronomers named 2013 the 'Year of the Comet'. Less popularized was the noticeable increase in fireball meteors observed in the Earth's atmosphere. Another year has passed and fireballs are still raining down like never before, with their rate apparently increasing exponentially.
has been cataloguing fireball events since 2002, and a couple of other websites have sprung up since then, but in general the lack of record-keeping and media coverage of this phenomenon is shocking, especially given how extraordinary the phenomenon is (or rather, was - apparently it's 'normal' now!) and whatever it may portend for civilization, sometime in the future, if not immediately.
One relatively new resource is the American Meteor Society’s ‘Fireball Logs', a database where eyewitnesses have been submitting reports of fireball events in the U.S. The AMS does subsequent checks to verify events with the All-Sky Fireball Camera Network set up by NASA's Meteoroid Environment Office (MEO) and other observation networks. Their stats are remarkable, yet they do fit with what we've noticed in recent years: the numbers just keep going up and up, and at an ever increasing rate!
Using the AMS data, which begins in 2005, I've created the following tables to give readers a visual for what's going on. Check this out:

The table below shows the number of fireball reports submitted to AMS between the years 2005 and 2013.

This is just the same RAW data being presented as before. As explained here an increase in reports does not necessarily equate to there being more fireballs. The raw data does not take into account for changes to the report form which made it easier to use, or that when the on-line report form first became available few people would have been aware of it compared to now, which is probably in part at least due to fireballs becoming newsworthy. Fireballs generally only make the news if there is footage, and up till a few years ago there were much fewer cameras (CCTV, fireball camera networks, Dash cams, phone cams). Prices have fallen and continue to fall whilst quality/performance has steadily increased, so more people own them now than ever. More cams means more fireballs being caught, and more making the news which increases public awareness and interest in the subject, which is bound to lead to more people looking for an online report form when they see a fireball, or simply coming across one when they are researching the subject.

I can think of 18 cameras (of various types) that are on my property (owned by my partner and myself) at this moment in time (and I'm expecting another in the next few days + I plan to buy another couple at least in the near future if finances allow). A decade ago it was just 5. 15 years ago it was just 2 or 3.

Mind if I ask how many "camera devices" you own/have owned previously?

Rezlooper
You say fireballs are very common but I disagree. Even observers from the All-Sky Camera Network would disagree. In an article from WayneIndependent.com about a fireball flash captured on camera in early 2013, a Thomas Cupillari observes the night sky through the Keystone College Observatory where one of these All-Sky cameras is set up. He said that it’s very unusual for fireballs to be so bright and stay so long. He said that only once he saw a fireball that stayed bright for more than 5 seconds. This is a person who studies the phenomenon every night.

The all sky camera is a fish eye lens that is pointed straight up into the air and can see 360 degrees around. The camera is in a network with Sandia National Laboratory through New Mexico State University. They are set up at various locations so common events that overlap can be tracked.
"The information from the cameras allows the laboratory to track where it came from, how high it was, and more," Cupillari explained. "It helps separate nature from manmade events."
The nearest location to the observatory is 80 miles south in Ottsville, which overlaps coverage.
"Regular meteors can be seen on clear nights and sometimes you can see several in one night, but fireballs aren't very common," Cupillari said. "One night our camera picked up 32 meteors and none of them were fireballs."

"Flash in the Sky" is a meteor

Notice how he states in the article that fireballs are not common. Thirty meteors in one night and not one of them was a fireball. If you look up all the sightings that have been occurring world wide over the past two years at the AMS site, you’ll see comments like this one quite often.


Kai L. of Livermore commented on the website, "I have done a considerable amount of stargazing in my 41 years on this earth and I have never seen anything this bright in the sky (besides the sun and the moon). I was completely stunned.”

Fireballs are rare when you compare them to meteors... and visible meteors are rare when you compare them to micro-meteors (detectable by radio), but putting things into context like this is only useful in certain situations and if the reader has actual experience observing.

In this case we are discussing someone who appears to be a reasonably experienced (if not very experienced) observer, and like I was saying earlier, if you put in the time you can increase your chances of seeing something big... however, I'd argue that he was "cheating" by using a camera that monitors the sky 24/7. His chances of seeing a big fireball were greater to begin with since most people can't monitor the skies constantly.

If you then consider big fireballs on a continental or global scale then they become relatively more common. In the context of one relatively small fireball camera network very big fireballs don't come along very often.

reply to post by FireballStorm


You make some good points...sure, some of this has to do with better reporting mechanisms, but regardless of the reporting mechanisms and communication sources, we would have heard about exploding fireballs. We just didn't hear about them and now we do, quite often I might add. You cited another exploding fireball over Argentina. IMO, the current thread about thunder in PA that shattered windows was most likely another exploding fireball. It occurred during the major storms that swept the nation so it was easy to dismiss this as thunder, but highly unlikely. I've never heard of thunder that shatters windows throughout a part of a city, but I've heard of fireballs doing this, a few times now this past year.

Here are some more recent fireballs; Puerto Rico, Sri Lanka and the UK. All coastal countries and this is several fireballs in the UK in recent days, which goes along with my theory about methane in the atmosphere having something to do with this flux of meteors penetrating deeper into the atmosphere. There's more methane release near the coasts from the thinner continental shelves due to land ice melt in Greenland and Siberia, but I won't get into all that right now. The UK has been hammered with relentless winds, waves and rain lately. It all fits.

Recent fireball around the world

Here's my thread on why I think fireballs are increasing;

Fireballs, comets and asteroids, oh my

fireballs are objects in the atmosphere...traveling at low speed ( close to 17,000 mph )

whereas meteorites or boloids, asteroids are traveling much faster --- say 20K 75K mph


ergo the increased 'fireballs' are likely orbiting space junk & possibly satellites entering the atmosphere... rather than cosmic (one off) visitors from distant places




rezlooper.... i liked your linked thread : "Recent fireball around the world "
but i think you are over analyzing the phenomena with methane in various levels of the atmosphere....

a fireball is like a Sci-Fi 'B' Movie depiction... with a flame and smoke trail...

reply to post by Rezlooper


Thank you for the reply Rez, and I appreciate your acknowledgement that you think at least some of the points I made are valid.

We will have to continue to agree to disagree on the main premise though - although I don't think we can say for sure that there has been a significant increase, it is possible that there might be more. It is just a question of waiting till researchers can get their hands on data that is independent of the human "quirks" that make the AMS fireball report data basically useless for this purpose.

To your credit, you are tenacious when it comes to this subject. I think Trillium's idea is a good one - if you are that passionate, then why not get your own fireball cam and monitor it? Then you could see for yourself, although obviously you won't get any answers overnight, and it will take a bit of funding. If you're interested feel free to drop me a u2u - there is a lens available on ebay right now that is usually quite hard to find which would be ideal for your purposes IMO, and very cheap too ($15). The CCD camera itself would cost you anywhere between $150-300 (a rough guess), depending on how good a camera you want, and software (UFO capture) costs $250. So not cheap by any means, but IMO worth doing if you can.

I am actually in the UK BTW, and we are getting another battering right now, although not quite as bad as in recent weeks. This kind of freakish weather is something that has been predicted for a long while as a consequence of climate change though.

reply to post by Rezlooper

At this increasing rate, I have no doubt in my mind that I will become one of these witnesses soon.

The only rate that has been shown to be increasing is reports not actual events.

I, myself have been studying this phenomenon for more than a year and I am convinced that fireballs have definitely increased in a big, big way, almost to the point of several of these bolides every passing day. Many of them are spotted and reports have been made.

What convinced you in your studies that the actual number of bolides is increasing and not the number of reports due to more interest, more people looking up and more people using the net?

Also, this handful of major fireballs you show is stretched out over centuries. Today, we’ve had more of these major fireballs documented in just one year…in Britian alone.

Its a 1 year period where 86 were documented between mid 1877-78.

Thanks for your reply St Udio...

St Udio

fireballs are objects in the atmosphere...traveling at low speed ( close to 17,000 mph )

whereas meteorites or boloids, asteroids are traveling much faster --- say 20K 75K mph

Hope you don't mind, but I'm used to talking about hyper-velocity objects in terms of km/s rather than mph, which gets confusing for me as I keep having to convert to km/s.

I think you are a little confused with the definitions and velocities - allow me to explain...

The vast majority of objects that hit the atmosphere are orbiting the Sun. These objects are divided in to two basic classes: Cometary and asteroidal material.

Asteroids originate in the inner solar system (the asteroid belt), and when they are nudged towards us (and therefore also closer to the Sun), as all objects in orbit do when they approach the Sun, they speed up.

Comets on the other hand originate in the outer solar system, and their orbits are much larger, which means that when they get nudged inwards they pick up even more speed by the time they get close to the Earth/Sun.

This basically means that cometary material is generally going faster than asteroidal material when it enters our atmosphere, although there are exceptions, but in the main it does hold true.

So at the high end, the maximum velocity cometary material in solar orbits attains (when entering the atmosphere) is around 72 km/s (eg Leonid meteors), and this high velocity is partly due to Earth traveling the opposite way, resulting in a head-on collision where the velocities of both objects are combined. Any faster than this and the object exceeds the escape velocity of our solar system, so it's no longer in a solar orbit, and barring any collisions would leave the solar system.

At the low end of the spectrum we have asteroidal material, which can enter the atmosphere at speeds as low as 10 km/s when it's traveling in the same direction as Earth and catches up with us. I'm not actually sure off hand what the max asteroidal velocity would be, but I would guess about 45-50 km/s tops.

Let's look at the definitions now...

A fireball is simply a meteor that is brighter than a certain value - speed is basically irrelevant, and they can be caused by either cometary material or asteroidal material. The definition of a "bolide" is much looser, but it's basically the same as a fireball - just a lot brighter. Bolides are brighter than fireballs because the objects that cause them are more massive, so they tend to penetrate deeper into the atmosphere where the air is more dense, and dense air/large mass means more light produced.

Asteroidal material tends to be significantly denser than cometary material, which combined with relatively low speeds means that a large enough fragment of asteroid can survive atmospheric passage to a lower altitude, but at around 50 km the air suddenly becomes much denser. It's at this point that many asteroids, due to hitting the "50 km wall", simply explode due to the increased forces and stresses. Any surviving fragments are too small to maintain momentum, and atmospheric drag quickly slows them down to free-fall velocity. It's only once the fragments reach the ground that they are called "meteorites", so technically meteorites don't travel fast at all unless someone finds them and takes them away. This is the category of objects that is responsible for all the "window rattling" type fireball events.

Cometary material tends to be so non-dense (some of it can be similar in density to cigarette ash!) that almost all of it disintegrates as soon as it enters the atmosphere - it just goes "splat"! It gives us our annual meteor showers, but it is not generally implicated with "window rattling" fireball type events.

St Udio
ergo the increased 'fireballs' are likely orbiting space junk & possibly satellites entering the atmosphere... rather than cosmic (one off) visitors from distant places

It's true that there is plenty of stuff in orbit, and that the occasional satellite does reenter resulting in a fireball, BUT, anything large is tracked, so even if they are not recognized as reentries at the time, most will be picked up later.

As well as that, a significant portion of fireballs today are caught on multiple cameras by fireball camera networks, which makes it possible to work out altitude, speed, and orbit. It's generally easy to tell a natural fireball from an artificial reentry, since they all have very shallow reentry angles, and the speed will never be more than 10 km/s - faster than this and they leave Earth orbit.

There is a little speed overlap between fast reentries and super-slow natural fireballs, but fireball cam data tells us that most fireballs are in the 20-25 km/s ballpark (Chelyabinsk was 19 km/s for example), which is way too fast to be a reentry.

Another good example is the 15 February UK fireball that I posted a link to in the OP, which was quite slow at 16 km/s, and has an orbit that suggests it originated in the asteroid belt:



Having said all that, you could be right that some of the small/small-medium size reported fireballs are caused by smaller fragments of junk in orbit that are not tracked.

Currently, about 19,000 pieces of debris larger than 5 cm (2.0 in) are tracked, with another 300,000 pieces smaller than 1 cm below 2000 km altitude.

Source: Wikipedia

So far though, I have yet to come across a case of a camera network catching a reentry, although I'm certain some must have. That to me suggests they are fairly rare compared with their natural counterparts.

There might also be a chance that satellite flares are occasionally misidentified as fireballs, since they resemble a very slow fireball, especially in extreme cases. Given that Iridium flares alone can be seen as often as 4-6 times from the same location on a quite busy night, it would not surprise me if a few snuck in unnoticed.