Near-Earth objects and close calls

[Ca.]

Are they prepping to search for the sun's sister?

The following article is about an extension of an observatory atop a mountain in the Pyrenees:

Un projet de deux nouveaux bâtiments au Pic du Midi de Bigorre

L'université Toulouse III - Paul Sabatier annonce le lancement d'un projet de création de deux nouveaux bâtiments à vocation scientifique pour une surface de 500 m2 au sommet du Pic du Midi de Bigorre. Pour un coût de 4,5 millions d'euros.

www.larepubliquedespyrenees.fr

publié le 15 novembre 2019 à 11h10.
Toulouse III University - Paul Sabatier announces the launch of a project to create two new scientific buildings for an area of 500 m2 atop the Pic du Midi de Bigorre. For a cost of 4.5 million euros.

A new real estate project begins at the summit of the Pic du Midi. With the creation in extension of two new buildings, the base of observation increases its capacity of reception and scientific accommodation of more than 500 m ².

The selection of the Tryptique architectural firm marks the first stage of this large-scale project led by the University Toulouse III - Paul Sabatier, funded for 500,000 euros by the State, 500,000 euros out of its own funds. and 3.5 million euros by the Occitania Region (including 3 million euros of European ERDF funds which it manages).

 

[Cosmos]

Came across this today and currently trying to wrap my mind around it:

Asteroid the size of the Great Pyramid could hit Earth in 2022

Scientists from the American space agency claim that asteroids the size of a football field collide with our planet every 2000 years, with another giant rock now heading towards the Earth. NASA just announced when a giant asteroid, known as JF1,...

www.sott.net

Something doesn't quite add up for me at this point, especially after creating the table mentioned above. Probably I'm missing data here. Notice that the story has gotten a lot of traction in the last days and that in almost no article you can find the actual full name of the object. You read "JF1", but very seldom the full name of the object, which you need to figure things out. I also noticed that I couldn't find the actual statements all those articles talk about "from NASA" in context of this object. At this point, I'm try to figure out what is going on exactly.

It is kind of a mystery to me at this point and somewhat odd. I've two possible candidates for now; "2009 JF1" or "2019 JF1". The odd thing though is that "2009 JF1", which seems to be the one they refer to, is listed at NASA as a max of 23 Meters in diameter (as opposed to around 130 as stated in the articles). Further, 2009JF1 is not listed at the same NASA page as coming close to earth at the stated date in the article, while on ESA's NEO risk page (which I discovered today!) it is listed as a substantial risk for earth at the stated date in the article (while also being a lot smaller than stated in the article). "2009 JF1" is not listed in my table above as coming close to earth at said time, while "2019 JF1" isn't listed there at all. Notice also that ESA currently lists 990 objects in their risk list for earth compared to the around 600 or so NEA's listed in my table above that came and will come closer to earth than the moon. Something doesn't quite add up here. How close will "2009 JF1" actually come in 2022? I couldn't find that data point anywhere as of now, including in all those articles. If it is "2009 JF1" they talk about, how can it be so dangerous to earth when it is not listed anywhere to come close to earth in any shape or fashion? Meaning nowhere close to 1 LD.

 

[Niall]

Are they prepping to search for the sun's sister?

The following article is about an extension of an observatory atop a mountain in the Pyrenees:

Un projet de deux nouveaux bâtiments au Pic du Midi de Bigorre

L'université Toulouse III - Paul Sabatier annonce le lancement d'un projet de création de deux nouveaux bâtiments à vocation scientifique pour une surface de 500 m2 au sommet du Pic du Midi de Bigorre. Pour un coût de 4,5 millions d'euros.

www.larepubliquedespyrenees.fr

c.a., I've edited your post to demonstrate how it should be done.

Posting a claim ("they're finding the sun's sister") then quoting an entire French media article that contains no reference whatsoever to either the sub-topic you're bringing in (the 'twin sun') or the actual topic of the thread - which is currently actively gathering data about NEOs - is a no-no. You can make your point - even if it is quite the s t r e t c h - but only discretely.

 

[Ca.]

It's my speculation and I should have stated so. Oh, not saying they found anyhting but feel that they are preparing for something.
But thanks I am getting the hang of it more now and understand your emphasis.
So thanks for the correction.

 

[Oxajil]

It is kind of a mystery to me at this point and somewhat odd. I've two possible candidates for now; "2009 JF1" or "2019 JF1". The odd thing though is that "2009 JF1", which seems to be the one they refer to, is listed at NASA as a max of 23 Meters in diameter (as opposed to around 130 as stated in the articles). Further, 2009JF1 is not listed at the same NASA page as coming close to earth at the stated date in the article, while on ESA's NEO risk page (which I discovered today!) it is listed as a substantial risk for earth at the stated date in the article (while also being a lot smaller than stated in the article). "2009 JF1" is not listed in my table above as coming close to earth at said time, while "2019 JF1" isn't listed there at all. Notice also that ESA currently lists 990 objects in their risk list for earth compared to the around 600 or so NEA's listed in my table above that came and will come closer to earth than the moon. Something doesn't quite add up here. How close will "2009 JF1" actually come in 2022? I couldn't find that data point anywhere as of now, including in all those articles. If it is "2009 JF1" they talk about, how can it be so dangerous to earth when it is not listed anywhere to come close to earth in any shape or fashion? Meaning nowhere close to 1 LD.

Yes, it's not quite clear where the articles get their information from. I went to the risk page you found, and set Table Settings to "All available data" and downloaded the Excel file (containing information about 22730 NEOs/objects). I found several JF1 NEOs. One that passed the Earth in 1955, one in 1982, one in 2019 (Sept 16th), and one that is said to make a close approach on July 3rd, 2029, and lastly one on Sept 29th, 2046. The maximum diameter of some of these JF1s is 100. I only found one 2009 JF1 and according to their data, it made a close approach in 2009. I couldn't find a JF1 one that fits the description of the article. Perhaps it hasn't been registered yet, or estimations change(d) (?). Hope this helps.

 

[thorbiorn]

Impact crater in Australia happened far more recently -- Sott.net stated:

In the state of Western Australia sits the famous Wolfe Creek crater, the aftermath of a 14,000-tonne meteorite crashing into Earth thousands of years ago.

For comparison the Chelyabinsk meteorite was 12-13,000 tonnes.
In the above article they make some estimates:

Extrapolating that for the rest of the planet isn't straightforward, but it gives researchers somewhere to start.

"Taking into account that arid Australia is only about one per cent of the surface, the rate increases to one every 180 years or so," says Barrows.

Previous studies have estimated Wolfe Creek-sized impacts should occur every 13,000 years, with smaller craters of about 150 metres across being left about every 500 years.

We are getting closer, but recall that Tunguska was not 180 years ago.

 

[MikaelYosef]

In the state of Western Australia sits the famous Wolfe Creek crater, the aftermath of a 14,000-tonne meteorite crashing into Earth thousands of years ago.

For comparison the Chelyabinsk meteorite was 12-13,000 tonnes.

I did a double take of the approximate weights for both meteorites. The Wolfe Creek crater is noticeable and a permanent(-ish) feature, versus the Chelyabinsk meteorite which punched through a frozen lake and left a relatively small hole. I know of the F=ma equation, but in simple analogies, two big trucks hit the earth - one caused a massive crater and the other one didn't. Would this only be due to the surface it hit or do the angles of entry, speeds and composition of both meteorites also contribute?

If I had to guess - I would say the Wolfe Creek meteorite could have smacked the earth at a perpendicular angle (i.e. head on), fast, and composed of something that didn't break up in the atmosphere easily versus the Chelyabinsk meteorite which came in at an angle, slowed down quickly relative to its initial approach speed in space and left a trail of debris burning up in the atmosphere.

 

[Cosmos]

Yes, it's not quite clear where the articles get their information from. I went to the risk page you found, and set Table Settings to "All available data" and downloaded the Excel file (containing information about 22730 NEOs/objects). I found several JF1 NEOs. One that passed the Earth in 1955, one in 1982, one in 2019 (Sept 16th), and one that is said to make a close approach on July 3rd, 2029, and lastly one on Sept 29th, 2046. The maximum diameter of some of these JF1s is 100. I only found one 2009 JF1 and according to their data, it made a close approach in 2009. I couldn't find a JF1 one that fits the description of the article. Perhaps it hasn't been registered yet, or estimations change(d) (?). Hope this helps.

Yeah I didn't get it either so far. I would also strongly guess that what those articles refer to is "2009 JF1". The given date for its close approach in the articles coincides with the risk list by ESA. Its size according to both NASA and ESA doesn't fit the size given in the article at all though. And yes that close approach is not listed in the NASA data table even though according to this flyby simulation (in which you can type in 2009 JF1) it comes a lot closer than 0.2 AU (29.920.000 Kilometers) to earth and thus should be listed at NASA, which it isn't. And with its supposed 2.000.000 Kilometers or so distance during its close approach in 2022 (which is a data point I could only figure out via the simulation and nowhere else so far) it will be a distance away from earth of well over 5 Lunar Distances. So why are the articles telling us that it poses so much of a danger to earth? And why is ESA also listing it as pretty dangerous object while NASA doesn't even list that close approach?

Something doesn't add up so far. Maybe estimations have really changed or something to that extent? Or it is indeed another object they are talking about that hasn't been added yet? (Which is in this case rather unlikely I think due to the way they number objects) Maybe the way ESA calculates the risk to earth isn't necessarily dependent/ascertained primarily by the distance to earth but also by other factors such as uncertainty which they give more weight?

Something along the line of the following could thus also be happening I guess (my speculation):

Let's suppose they find a new NEO which is only observed shortly before it disappears into the dark again. Due to the short observation there is probably a high uncertainty assigned to it in regard to its size and flight path and thus its close approach. Let's assume they calculate the close approach of this object at a distance of 5 LD. Let's further assume they have discovered another object that they were able to observe/track for a long time which then accordingly is assigned a much lower uncertainty in regard to its size and flight path and thus its close approach. Let's assume they calculate the close approach of this second object at a distance of 0.2 LD (much, much closer to earth). It could very well be I guess, that due to the large uncertainty of the first object, ESA gives the first object (via the priority they give to certain factors in their calculations) a much higher potential risk factor of impact, even though from what they have calculated it will pass much further away from earth. In other words; the risk page they developed doesn't have to reflect reality at all in terms of which object will really be a risk. Or so it seems to me at this point!

Having said that, in general, I've been rather skeptical (and now even more so, after looking closer into it) how certain they can be at all in regard to sizes and flight paths in terms of how close and dangerous NEO's can really get. There are quite a number of huge uncertainties involved, some of which they probably don't even take into account in their calculations; such as potential disruptions of NEO orbits by electric/gravitational forces acting on the object when it flies by an unknown larger object (or cluster of objects and dust) for example. They can neither know nor calculate something like that (because it is an unknown factor) even though it probably happens more often than not. Let's say for example they observe the orbit of an object with high certainty (lets say with a close approach of 0.1 LD) and then it disappears again. Then lets say this objects encounters another Unknown object on its orbit after it has disappeared from our radar, which changes its orbit, even just slightly, due to electric/gravitational forces. How could they ever know how the new orbit after this encounter looks like? I would say, to know that is pretty much impossible.

I'm not even sure how reliable their calculated orbits, sizes and close approaches of NEO objects is in general (present, past and future). So even if they think they know with high certainty what the size and flight path of an object is, there might be a number of factors which makes the reality of this rather difficult to ascertain. Have they for example ever really been able to truly check their theoretical calculations of sizes and orbits of such objects by rather close and reliable inspections/measurements/observations? I would guess that this has never really happened due to the nature of the phenomena. Let's say for example that they have discovered an object 2 LD away which they have calculated with a rather specific size and orbit. In order to truly check if what they calculated is in actuality happening, I would assume that such an object has to come pretty close to earth in order to countercheck/measure against this theoretical calculation? Has that ever happened to a reliable degree that is not loaded with assumptions and uncertainties? I mean, even if such an object is hitting our atmosphere or the ground even, we have a very hard time to give it a precise size or orbit.

I'm also reminded of how even the C's make it rather clear how difficult it is (for them!) to ascertain the true orbit and "timeframe" that such an object could get dangerous to earth. We haven't even taken into account non-linear (quantum) forces and actions in all of that. So even if you only consider the nuts and bolts mechanical and electrical forces, there is already so much uncertainty involved.

 

[Carl]

I did a double take of the approximate weights for both meteorites. The Wolfe Creek crater is noticeable and a permanent(-ish) feature, versus the Chelyabinsk meteorite which punched through a frozen lake and left a relatively small hole. I know of the F=ma equation, but in simple analogies, two big trucks hit the earth - one caused a massive crater and the other one didn't. Would this only be due to the surface it hit or do the angles of entry, speeds and composition of both meteorites also contribute?

If I had to guess - I would say the Wolfe Creek meteorite could have smacked the earth at a perpendicular angle (i.e. head on), fast, and composed of something that didn't break up in the atmosphere easily versus the Chelyabinsk meteorite which came in at an angle, slowed down quickly relative to its initial approach speed in space and left a trail of debris burning up in the atmosphere.

This sounds about right. If it was a more shallow trajectory it could have a way longer time travelling through the atmosphere in order to burn up. Then you also have the initial speed that it comes in at, and perhaps the composition of the asteroid, the density of the material, the electric charge and probably more that I'm not aware of.

 

[thorbiorn]

I know of the F=ma equation, but in simple analogies, two big trucks hit the earth - one caused a massive crater and the other one didn't. Would this only be due to the surface it hit or do the angles of entry, speeds and composition of both meteorites also contribute?

As you mention there are other variables besides mass. Below I will try to address some of them, including speed and composition and using a little mathematics and phycis from high school.

What is the importance of the speed?
The kinetic energy, Ekin is calculated as 1/2*m'v^2 That is half of the mass of the object multiplied by the velocity squared. That is why when we drive a car the braking distance is four times greater when we double the speed. In other words we need to be much much more aware and look much much further ahead when we drive and increase the speed of the car we drive. In terms of a meteor if the speed is double it has four times more energy than one of the same mass with only half the speed. Consequently a crater, its size and depth would be affected very much by the speed of the object.

If one looks at the Wiki for the Wolfe Creek meteorite they say it was about 50,000 tons which is much more than 14,000 tons. We do not know what is the truth, but to defend the number of the 14,000 tons in the recent article an object of 14,000 tons with less than twice the speed (1,89 times the speed) of a 50,000 tons object would have the same kinetic energy. Isn't that amazing?

What is the importance of composition?
How come the object in Chelyabinsk did not leave much of a crater compared to the Wolfe Creek crater, when the estimated mass was comparable 12,000-13,000 vs 14,000 tons. We have already mentioned the issue of speed, but if for a moment we assume the speeds where within the same range and the only difference was the slightly lower mass then how to explain the difference? From what we hear the hole in the ice was pretty round and the crater in the creek was too, so although there probably was an angle, it was not a very flat one, at least not in the final phases. One question to ask would be WHEN were the meteors having the weights mentioned. Here we know that the 12,000-13,000 tons in Chelyabinsk was at the time of entry into the atmosphere of the Earth, before hitting Earth, while the largest fragment found was less than 600 kg and other parts found were not big. The rest of the Chelyabinsk meteorite is estimated to have burned up or left behind as dust in the atmosphere.

One reason for this large difference between the estimated initial mass and the mass found in the case of the Chelyabinsk meteorite may be due to it being a chondrite. Chondrites are stony meteorites; they are the most common ones, have a lower density and fragment much easier than iron rich meteorites. Iron meteorite - Wikipedia explains:

• They are much more likely to survive atmospheric entry, and are more resistant to the resulting ablation. Hence, they are more likely to be found as large pieces.

It turns out the meteor at Wolfe Creek is estimated to have been a iron meteorite. This is what the Wiki has and one paper abstract explains:

[...] fragments of the impacting meteorite (a medium octahedrite) have been recovered.

The reference is: C. O'Neill & C. Heine (2005) Reconstructing the Wolfe Creek meteorite impact: deep structure of the crater and effects on target rock, Australian Journal of Earth Sciences, 52:4-5, 699-709, DOI: 10.1080/08120090500170450

And about octahedrites there is in the Wiki:

Octahedrites are the most common structural class of iron meteorites. The structures occur because the meteoric iron has a certain nickel concentration that leads to the exsolution of kamacite out of taenite while cooling.
[...]
Octahedrites derive their name from the crystal structure paralleling an octahedron. Opposite faces are parallel so, although an octahedron has 8 faces, there are only 4 sets of kamacite plates.

This means that if we have two meteors that have the same speed and the same mass, but one has a stony composition and the other a metallic iron rich composition, then the metallic one is going to tolerate the impact with the Earth atmosphere much better, because it can withstand greater external forces without fragmenting. Compare beating a stone with a hammer with hammering away at a piece of iron. Children in middle school can safely repeat the experiment, if they and any onlookers use safety glasses. From this consideration it makes sense that the Wolfe Creek impact crater is much more substantial than the impact site on the frozen lake near Chelyabinsk.

Here is the gif link, which one needs to click to watch for an illustration from the Wiki of the process of fragmentation as a large meteor or bolide enters the Earth atmosphere:

Bolide - Wikipedia

en.wikipedia.org

Along the way of trying to explaining this case I found out that indigeneous Australians said about the crater at Wolfe Creek that: "when a rainbow serpent fell into the crater". The story is below:

Serpents, meteorites and murder — the many stories of Wolfe Creek Crater

Rare audio recordings reveal Aboriginal people may have worked out how Wolfe Creek Crater was formed, years before scientists arrived and it become a destination for fans of the eponymous horror movie.

www.abc.net.au

Why Wolfe Creek Crater attracts scientists, Indigenous traditional owners and horror movie fans

ABC Kimberley
By Erin Parke
Updated 7 Jul 2019, 2:50am

[...]

PHOTO: Dr John Goldsmith has recorded the creation stories of Wolfe Creek Crater. (Supplied: John Goldsmith)
[...]

The Indigenous stories
Incredibly, the vast crater was not noticed by white people until 1947, when geologists surveying the remote Kimberley spotted the circle from the sky.

But for thousands of years prior it was a gathering place for the Jaru and Walmajarri people.

While the stories associated with the area are rich and varied, Jaru woman Katie Darkie agreed to share those passed on within her family.

"My grandfather's and my mother's country is the Wolfe Creek Crater and around there … it's a really special place to our people," she said.

[...]

"In gudia [whitefella] world they say the meteorite fell from the sky to the crater, but Aboriginal people, when they were living there for many, many years, they said it was from when a rainbow serpent fell into the crater, and that's the dreaming of our people."

Ms Darkie said local families called the crater Kandimalal, which means no potatoes, as local people noticed the tasty bush potato didn't seem to grow in the area around the crater.

She has another story that was shared to her as a girl.

"The old people would tell us the story of one old man who went hunting from Sturt Creek [40km east], and he went through the river and he was hunting birds with his dingo and he heard the bird singing on the other side but he didn't know where he was going," she said.

"Then he came up at the other side, he came up through the Wolfe Creek Crater, and so all the people said, in the old days, that there was a tunnel that runs through the ground from Sturt Creek to the crater."
[...]

 

[Ca.]

https://twitter.com/x/status/1198836267779346432

Snip Last Paragraph:

In addition to finding evidence that Scholz’s star had an ancient interaction with the Oort cloud, the team also determined that eight of the objects they studied (including the recent interstellar visitor ‘Oumuamua) are traveling so quickly that they likely originated from outside the solar system. Furthermore, these eight objects all have radiants that are relatively well separated from the others, which suggests their orbital paths are unique and uncorrelated. Two of these objects, C/2012 SI (ISON) and C/2008 J4 (McNaught), have extreme velocities of around 9,000 miles (14,500 km) per hour, which strongly indicates they are interstellar objects zipping through our solar system.

Although more research is needed to confirm the study’s findings, the results show that astronomers may not need to wait to study an interstellar object until it serendipitously slingshots around the Sun like ‘Oumuamua did. Instead, statistical studies like this could be used to help astronomers proactively identify the most likely extrasolar visitors for future analysis.

A free pre-print version of the study is available online at arXiv.org.

https://twitter.com/x/status/1197666049585537024

 

[Wu Wei Wu]

As it happens, a couple of days before you asked your question, I started to get curious about apparent recent influx of objects coming fairly close to earth. Up front, it should be stated that the subject matter, of really putting a hard undeniable finger on whether an increase is happening is a very complex subject matter because of the very nature of the subject. You would also have to define what exactly "normal" is in that context. There are so many variables and uncertanties involved, not just on the technical dimension, but also on the human dimension, that it is pretty much impossible at the moment to say anything for certain or with "100% proof".

Having said that, from my pretty extensive dive into the subject for years, I can tell you that the idea that there is a fairly stark influx of comet/asteroid bodies both in the solar system as a whole, as well as close to earth recently, is a fairly good estimate that is supported by many data points and seems to be true. As itellsya pointed out though, this estimation is based on a whole set of areas. If you want to have one source of data that conclusively proofs or disproofs this idea, I can tell you that this is pretty much impossible with this subject matter at hand.

If however, one wants to put a finger on it, that might come to a rough approximation of the current state of affairs, I think the Data-Sets provided by the American Meteor Society are the most reliable in terms of a single source showing what most likely is going on at the moment. A old table (last updated 2017) including graphics can be found here. A new updated table that includes 2017 and 2018 looks like this now, and can be found here:

View attachment 32377

One of the reasons I think the AMS data is probably closest to the truth in terms of single source is the way the data is gathered, selected and processed. It is based on people reporting seeing fireballs in the atmosphere of the earth. This de facto makes the argument of "improved technology" rather hard to defend in explaining this exponential increase. As Pierre also pointed out in his book "Earthchances and the Human Cosmic Connection", that dataset is hard to explain by improved technology, especially considering the significant dips in reports in 2015 and 2018 (while climbing up before and afterwards), while still being orders of magnitude higher than just 10 years earlier.

How likely is it that people within the US all of a sudden started to look more into the sky, considering all the distractions, including cellphones and light pollution, that makes seeing things in the sky more difficult? How likely is it that more people take notice of what is happening in the sky around them and therefore report more of this? In fact, if anything, the exact reverse seems to be happening; ever more people seem to take less notice of what is happening above their heads and instead looks at their screens. So how can this explain the exponential increase? And are we to assume that the technology wained down in 2015 and 2018 respectively or that people in those years where just less interested in looking above their heads?

There is also a pretty consistent exponential increase noticeable in pretty much every other data-set you can look at, that closely parallels with this fireball increase. Just a coincidence and explainable with "improved technology"? In itellsya post, you can find some of those data sets, that go beyond just earth itself, out into the solar system. And then we also have all the new moons around the outer planets being discovered. Here also, Pierre made some good arguments in his book that speak against the idea that this all might be due just do to "better technology" over the years. Also thorbions posts above is important in understanding the complex nature of the subject as well as the vast distances and spaces involved.

Which brings me to what I originally wanted to post about; Close encounters with NEO's since the record began till present and future and how that might compare to all of this other data. Even more interesting though, are the questions and conclusions that could be drawn from the data-set I'm about to present below and possible ways to discover connections with the fireball data (observed by people on earth) and things happening on the globe in other areas.

See next post.

Thanks for doing this. It looks like great work.

Is there any data available on website traffic to AMS? How do we know there isn't just more people calling in sightings, due to the ease of accessing and finding AMS? That could account for the fireballs and explain why the numbers are levelling off: more people have been seeing fireballs, then they google it, then they report it, but eventually the numbers stabilize as most sightings are reported (and remain somewhat regular from year to year).

I'm not saying fireballs should follow a normal distribution, but we should make sure we aren't fooling ourselves here.

Though this would be a much weaker explanation for the NEOs. For the NEO increase, the question to ask is:
Do we have better NEO monitoring tech than we once did? and... (Better tools getting us more visibility, to the degree justifying the increase)
Do we have more people using the NEO monitoring tech finding more NEOs? (An increase in the utilization of existing tools, to the degree justifying the increase)

I don't really know how to find answers to these NEO questions.

 

[goyacobol]

Though this would be a much weaker explanation for the NEOs. For the NEO increase, the question to ask is:
Do we have better NEO monitoring tech than we once did? and... (Better tools getting us more visibility, to the degree justifying the increase)
Do we have more people using the NEO monitoring tech finding more NEOs? (An increase in the utilization of existing tools, to the degree justifying the increase)

I don't really know how

@Wu Wei Wu ,

Not to alarm you but does it matter whether we now have better detection systems or does it make sense to be prepared for the worst possible scenario since it depends on the quality of what we have now as sources of accumulating data that supports possible NEOs .

If you have any confidence in what the Cs have been saying for years now then you should realize it is not a matter of "proof" but that intrinsic gut feeling at times that things are heating up both earth-wise and cosmically.

If you are enamored of current scientific expert opinion then we should just all go vegan and enforce carbon taxes to prevent global warming and ignore the solar minimum and approaching ice age.

Never mind a possible brown dwarf star that our "existing tools" are only beginning to detect.

I don't know what to say to you in that respect other than I would give it a second thought.

For now, I would just say consider what we do not really know yet:

Session 21 December 2012:

Q: (L) There was something else I wanted to ask about. (Andromeda) What about that humming sound that we all heard awhile back in the office?

A: Electrical charge.

Q: (L) How come we can't measure things like that?

A: Everything else including instruments are within the system.

There is so much we do not know and trying to measure what is to be expected will be dependent on many factors that are difficult and almost impossible to ascertain whether these increases in frequency being reported are new or repetitions of past cycles that have gone before.

 

[thorbiorn]

The data shows more surprise NEO flybys to be expected - at the going rate about one per week

You can find all the graphs above in more detail here as well as the main table from which all of this is derived here. There is a lot more interesting data that can be pulled out. For example, we haven't even mentioned the future encounters or how the past ones might relate to happenings on earth.

Great work Pashalis. Your question gave the idea to use your data to generate an estimate of what the outlook is. What kind of surprise discoveries of NEO's and near misses within one Lunar distance can we expect in the next couple of years based on the published data?

The procedure was to make a copy, order the data according to difference between discovery and close passage. When one does that one discovers that there is a lot between plus to minus 13, but then it is minus - 366 (close passage a year ago from date of discovery) and then plus 192 (close passage more than half a year in advance). For this reason, I decided to hide all the data outside plus minus 13 days which then leaves us with the surprise discoveries that comes out of deep space. After that I ordered the less than two week surprises by year and counted them, but I didn't bother about finding out whether there in recent years has been more on the plus side than the minus side, a quick review of the colours shows little has changed. Below is the diagramme and to give a true picture I inserted the years where nothing was observed or noted.


From the above diagramme, we see that there most certainly has been an increase and in spite of technological advances and more focus on the subject, the surprises keep coming at a rate of one per week. This trend has been steady and even rising for the past four years, which means that there is a good chance we can expect at least that many surprises in the next few years.

In the above diagramme one NEO did not make it, it was the Chelyabinsk super bolide. A super bolide is at least 100 times brighter than the full moon. The Chelyabinsk meteor was many time more than big enough to have qualified as a NEO danger had it been discovered in time. Actually there are many others that did not enter the diagramme, because they did hit the planet, as surprises before they got listed as NEO of which the max size of the smallest one in the official table is 1.4 meters, the next 2.1 meter and up: From Fireballs there is a most recent picture of impacts in the last about 30 years. We have seen image before, but in this context is shows what is being missed from the tables and diagrammes of potential threats.

 

[thorbiorn]

An attempt to estimate the real number of superbolide size NEO flybys within one Lunar distance
There was in Near-Earth object - Wikipedia

the number of asteroids brighter than H = 30 (larger than 3.5 m (11 ft)) is estimated at about 400±100 million—of which about 0.003 percent had been discovered by February 2016.[96]

This means that the reporting of NEO flybys discoveries, even if the above half a billion are not, or are not yet within 1 Lunar distance, the potential for NEO flybys within 1LD to take up quite a few headlines in the coming years is substantial. In case the reporting of these gets reduced or twisted, the direct observations on the ground coupled with a knowledge of how to extrapolate will help, because the real figure of NEO flybys should be something like what we see fall on Earth every year multiplied by 200,000.

If we instead take the distance to the Moon, then the average distance is 238,855 miles. To find the ratio of misses to hits we first have 238,855 miles /4000 miles per each Earth radius. This gives us close to the equivalent of 59-60 Earth radii between the center of the Earth and the Moon. 59^3 is 205.379. In other words, for every strike there will be around 200,000 misses passing by within the space of a celestial globe around the Earth that extends to the average distance of the Moon.

The above discussion raised some questions about bolides. How big are they?
I tried to look up the size of a bolide to see if there is a match with the NEO range of sizes. One opinion is found in a book published in 2004 by Cambridge University Press but can be had cheaper from Amazon It is edited by M. J. S. Belton, Michael J. S. Belton, Thomas H. Morgan, Nalin H. Samarasinha, Donald K. Yeomans:


In a chapter called Physical properties of comets and asteroids inferred from fireball observations pages 153-166 written by Mario Di Martino and Alberto Cellino there is on page 155 a description of the various velocities of these objects. Knowing the relation between mass, velocity and energy we can calculate that an object moving at 11 km/s compared to a similar object moving at 72 km/s will only have 2.3% of the energy and this would affect what we observe if they entered the atmosphere simultaneously. The faster object would be more spectacular.

And on page 156 they inform us about what optical effects generated by a fast moving meteoroid entering the atmosphere.

The above taken together means - including observed superbolides on Earth and the size of the space out to one Lunar distance - that to obtain a rough real number of superbolide size NEO flybys within 1 LD, we could take the number of observed superbolides on Earth and multiply it by 200,000, because no matter where in this space where I would put the Earth in this space measuring 200,000 times its size, it would assuming an equal distribution of superbolide size NEOs on avearage be hit by the same number.

Suppose there are five (5) superbolides a year observed on Earth, then it would mean there are 1 million (5x200,000) superbolide size flybys within 1 LD. This is an intimidating number, I wish a mathematical physicist could tell me the model I am using is faulty, that the number of superbolide size NEO flybys is only a fraction, but then on the other hand, perhaps the problem is not the model or the numbers, but to imagine the vastness of cosmic space, how small we really are, and how little we in spite of all our technology actually know about what is out there.