Scientists stunned by ‘city-killer’ asteroid that just missed Earth(seattletimes.com)
seattletimes.com
Scientists stunned by ‘city-killer’ asteroid that just missed Earth
https://www.seattletimes.com/nation-world/scientists-stunned-by-city-killer-asteroid-that-just-missed-earth/
160 comments
Ok little pet peeve of mine:
Every other time I hit some arbitrary Twitter limits of a post and 5 minutes later I can access it.
At this point I believe it is to bully me into an account or using the app or something.
I have a bunch of profanities in reply to this.
Every other time I hit some arbitrary Twitter limits of a post and 5 minutes later I can access it.
At this point I believe it is to bully me into an account or using the app or something.
I have a bunch of profanities in reply to this.
Twitter for mobile (web) is filled with dark patterns like these. They do everything in their power to make you download their app, including limiting and/or sabotaging features that would obviously work on any web browser.
For example, you can see someone's tweets but you can't click on the mentions or media tabs. Search is downright unusable. Try searching for something and scrolling to the top to get the latest results.
I know I make no difference at all for the folks at Twitter, but they certainly lost me as a loyal user after witnessing such shady practices.
For example, you can see someone's tweets but you can't click on the mentions or media tabs. Search is downright unusable. Try searching for something and scrolling to the top to get the latest results.
I know I make no difference at all for the folks at Twitter, but they certainly lost me as a loyal user after witnessing such shady practices.
"We've detected that you are not willing to execute arbitrary code we hand you. Would you like to proceed to legacy Twitter?"
[Yes]
[Yes]
I have the same issue on Chrome on Android and I always reload the page (not the Twitter reload button), which always seem to work for me. I don't know if they do this on purpose, but it does make you wonder. I do not want the Twitter-app on my phone.
Indeed, reloading the page seems to work for me. Seems like an intentional dark pattern to force people to register and download the app.
Are you using Firefox on Android? Using that I almost always get the rate limit error. Never seen it otherwise.
You can bypass this by using the 'Request Desktop Site' checkbox.
Ironically, requesting the desktop site uses more bandwidth, defeating the purpose of a rate limit.
Ironically, requesting the desktop site uses more bandwidth, defeating the purpose of a rate limit.
Resubmitting the url without the 'mobile' subdomain also works for me every time for some reason. Same setup setup with Firefox on Android. It's infuriating.
I get the limit in Android with both Chrome and Firefox. All the time.
Yeah I get the rate limited error every time. I think Twitter just marks anyone not using the app as a bot
what does '2019 OK' mean, is that the rock name?
It would be good if your bot attached some sort of 'oh shit' scale, based on size and closest approach
It would be good if your bot attached some sort of 'oh shit' scale, based on size and closest approach
It seems to be a naming convention for provisional names (https://www.quora.com/How-are-asteroids-named)
2019 OK :
- "2019" => discovered in 2019
- O => discovered in 2nd half of july
- K => 10th object discovered in this period
2019 OK :
- "2019" => discovered in 2019
- O => discovered in 2nd half of july
- K => 10th object discovered in this period
Why isn’t I in the second table?
Probably to prevent confusion with "1"
'2019' = present year,
'OK' = we didn't get wiped out
Does it handle the case when something doesn't miss?
No, but it's open source, so maybe future surviving generations can pick up that issue?
https://github.com/tomtaylor/lowflyingrocks
https://github.com/tomtaylor/lowflyingrocks
How would it bypass the fail whale?
This is fantastic, thank you!
That is awesome, thank you!
This is actually really common for smaller ones:
2015: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
2016: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
2017: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
2018: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
All the ones coloured red in the tables (the majority) weren't discovered until after their closest approach.
2015: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
2016: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
2017: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
2018: https://en.wikipedia.org/wiki/List_of_asteroid_close_approac...
All the ones coloured red in the tables (the majority) weren't discovered until after their closest approach.
"More than 90 percent of those (extinction-level) asteroids, which are 1 kilometer, 0.62 miles, or larger, have already been identified by NASA and its partners."
How do they know it's 90%? I mean, if the denominator is unknown? If the denominator is known, then doesn't that mean they've identified them?
How do they know it's 90%? I mean, if the denominator is unknown? If the denominator is known, then doesn't that mean they've identified them?
Abundance estimation is a big problem in ecology (and other fields), and they’ve developed some clever ways to estimate population sizes without doing an exhaustive census.
One popular approach is a capture-recapture experiment. On your first trip, you find as many of your targets as possible and mark each one. With turtles, you might paint something on the shell; here, it might be something like determining its orbit and other characteristics. You wait a bit, and search again (starting from scratch), but this time you separately record the number of “new” specimens and the number recaptured. A tiny bit of algebra from these three numbers gives you an estimate of the population size.
One popular approach is a capture-recapture experiment. On your first trip, you find as many of your targets as possible and mark each one. With turtles, you might paint something on the shell; here, it might be something like determining its orbit and other characteristics. You wait a bit, and search again (starting from scratch), but this time you separately record the number of “new” specimens and the number recaptured. A tiny bit of algebra from these three numbers gives you an estimate of the population size.
It comes with a bias though, since your searches will bias towards finding asteroids that are easiest to find using your search method.
Correct, and since that bias is towards larger NEOs, which are relatively easier to detect then smaller objects, they can be reasonably confident about that estimate.
It is the medium to small size NEOs that are the most worrisome. They are harder to detect, and hence harder to estimate how many are out there.
Seems like a bigger problem for turtles than for asteroids.
I mean, asteroids don't deliberately hide.
Sure, some are darker and/or have a less visible radar profile or whatever, but the variations seem manageable.
I mean, asteroids don't deliberately hide.
Sure, some are darker and/or have a less visible radar profile or whatever, but the variations seem manageable.
They don't deliberately hide, but (as mentioned in the article) they can vary dramatically in how visible they are to us over time if, for example, they have a highly eccentric orbit.
Show me a measurement that doesn't come with bias
I have one apple.
Oops, it was an Asian pear: https://en.wikipedia.org/wiki/Pyrus_pyrifolia
Survivorship bias
You took a bite off it though, so your measurement is in fact biased. Other people might measure 0.75 apple instead.
It’s a statistical argument based on the observed distribution of asteroids. It’s not precisely true, and could even be widely incorrect, but they think it’s likely to be in the correct neighborhood.
Also, after a certain size things become significantly easier to detect with your existing instruments, so there is some confidence from that.
Also, after a certain size things become significantly easier to detect with your existing instruments, so there is some confidence from that.
Related to this (though maybe not directly applicable), in certain scenarios there is a difference between what can be reliably detected vs tracked. For example, in the context of debris orbiting the earth, our radars can take LEO census measurements down to 3-4mm, even though we can only reliably track things on the ~10cm size range.
We can therefore semi-confidently say we know how many 1cm objects there are out there, even if we can’t predict the trajectory of any single one. (Similar to atoms, really)
We can therefore semi-confidently say we know how many 1cm objects there are out there, even if we can’t predict the trajectory of any single one. (Similar to atoms, really)
The mark-recapture method has been mentioned. Additionally, you can create fake data and run it through your search algorithm to get an estimate of your detection efficiency.
IIRC, the 90% estimate is based on how often searches encounter previously cataloged objects.
It missed Earth by 73,000 kilometers; Earth has radius 6,371 kilometers.
(79371 * 79371) / (6371 * 6371) = 155.2
This was a game of darts in a galactic pub. The dart hit the dart board, but not the bullseye (Earth). One in every 155 times we play this game, it ends badly.
(79371 * 79371) / (6371 * 6371) = 155.2
This was a game of darts in a galactic pub. The dart hit the dart board, but not the bullseye (Earth). One in every 155 times we play this game, it ends badly.
How often do we play this same game, though? If a 1Km size asteroid seems to hit the Earth about once every 500,000 years, it would seem like they would pass this close to the Earth only once every 32,000 years or so.
So either the 500Ky figure is wrong, or we've been extremely lucky to witness a once-in-30Ky event, or we're missing something.
So either the 500Ky figure is wrong, or we've been extremely lucky to witness a once-in-30Ky event, or we're missing something.
This was only 100m. Those probably hit semi-regularly and would have usually gone unnoticed or at least unrecorded before modern times.
Incredibly in Australia there are impact events recorded in indigenous oral tradition dating back thousands of years.
http://www.aboriginalastronomy.com.au/content/topics/craters...
http://www.aboriginalastronomy.com.au/content/topics/craters...
Even if it hit the earth the odds of it landing anywhere near a city are slim. 3/4 of the time it hits the ocean, Siberia, the Canadian north, or the Antarctic.
Although an asteroid of that size, depending on its makeup, can have other damaging effects. For example, by area, the pacific ocean covers a lot of the planet. An asteroid hitting the pacific can cause a tsunami that could seriously damage any coastal city in range.
Even a 390 ft nickel-iron asteroid wouldn’t have enough energy to create a meaningful tsunami. We’re talking energy along the lines of Castle Bravo, not the asteroid that killed the dinos.
An asteroid of this size would need to land within 1000 ft of shore to have any meaningful wave height, and would only significantly impact maybe a mile of shoreline. You need to move an impressively large volume of water to create a Fukashima-type event.
Serendipitously cooling the surface of the earth down by exactly 2.2 C.
Perhaps the solution to climate change is dropping a rock the size of a stadium on Canada every few years.
Mine some ice from an asteroid and drop it into the ocean, with larger blocks every few years as pollution increases :-)
Much of the ice would vaporise on entry. Water vapor is a greenhouse gas.
Yes. But more importantly, that was a Futurama reference: https://www.youtube.com/watch?v=6cjx4gJFME0
It can either both prevent sunlight from entering or leaving depending on the altitude.
[deleted]
Bring it, punk!
One thing to note: the Tunguska meteor was ~50-200m in diameter, and was equivalent to a 3-30 mega-tonne explosion.
You massively underestimate the destruction caused by a 1km asteroid. Remember some scientists estimate the asteroid that killed dinosaurs was as small as 11km. In other words a 1km one may be 1/10th the diameter needed to cause an extinction-level event.
A 1km asteroid will cause massive casualties no matter where it impacts. If it hits the ocean it will cause a tsunami. If it hits a remote land it will eject so much debris in the atmosphere that they will block sunlight around the globe and reduce temperatures by multiple degrees, thus reducing food crop yields and causing worldwide food shortages and famine.
A 1km asteroid will cause massive casualties no matter where it impacts. If it hits the ocean it will cause a tsunami. If it hits a remote land it will eject so much debris in the atmosphere that they will block sunlight around the globe and reduce temperatures by multiple degrees, thus reducing food crop yields and causing worldwide food shortages and famine.
This was a 100m asteroid (city killer), not 1km.
And a factor of 10 difference in linear size (radius, diameter, etc.) implies a factor of 1000 difference in mass.
How does the math change when you take into account the fact that Earth exerts a gravitational pull on the asteroid?
It probably has no effect: objects that are not in stable orbits around the earth are going to be in hyperbolic orbits relative to the Earth's gravitational field. A dangerous asteroid would need a periapsis lower than the Earth's radius by a certain amount to hit the Earth, so the risk of collision is still roughly proportional to Area. If gravity is a factor I would expect it to be a high order term. Atmospheric effects are probably more significant.
Interesting question, not sure. As the speed of the astroid is goes up, the relevance of gravity goes down. As the speed goes down, the damage it can do also goes down, and also reduces the probability of an encounter.
The degree of gravitational focusing depends on the speed of the incoming object, but I seem to recall that for typical interplanetary velocities it's of order 1, ie not huge.
It may not change this encounter much, but it could change
the orbit just enough for some future earth-orbit
crossing - as could the gravitational effect of any of
the other planets, their moons, and all the other asteroids
change the orbits of anything out there. Solar systems
can be messy places, over geologic time frames.
Sometime, sooner or later, we will have a significant
impact.
And does that make it more likely to miss? Ie it gets slung around by gravity instead of hitting?
Thinking out loud time! My favorite!
To matter for a single pass, the object must be small and/or traveling slowly. Otherwise, itll just keep on cruising.
Iteratively is a different story. Many objects repeatedly cross earths path. How that orbit changes over time i suppose is a function of the other gravity wells the objects pass when they arent near earth. I expect there are so many confounding gravities that only a certain belt\torus exists in the universe where, inside that torus, space stuff is capable of running into us.
Side note: this article is clickbaity because it implies no one knew asteroids almost crash into us without us knowing, but thats not true. People know. There are hard reset buttons floating around in space and we might just press one without warning.
https://en.m.wikipedia.org/wiki/Potentially_hazardous_object
To matter for a single pass, the object must be small and/or traveling slowly. Otherwise, itll just keep on cruising.
Iteratively is a different story. Many objects repeatedly cross earths path. How that orbit changes over time i suppose is a function of the other gravity wells the objects pass when they arent near earth. I expect there are so many confounding gravities that only a certain belt\torus exists in the universe where, inside that torus, space stuff is capable of running into us.
Side note: this article is clickbaity because it implies no one knew asteroids almost crash into us without us knowing, but thats not true. People know. There are hard reset buttons floating around in space and we might just press one without warning.
https://en.m.wikipedia.org/wiki/Potentially_hazardous_object
Why would the size of the object matter in this instance?
Mass, not really size. The smaller the object relative to earth, the more its course is changed by earths gravity.
You may want to refer to Galileo's leaning tower of pisa experiment...
Assuming no other conditions change, and that the object crosses Earth's orbit as the planet is passing by, and so on.
I'd be willing to bet, however, that this object's orbit permutes a bit with every pass, especially dipping that deeply into the gravity wells of other, much more massive, objects.
I'd be willing to bet, however, that this object's orbit permutes a bit with every pass, especially dipping that deeply into the gravity wells of other, much more massive, objects.
It was described as "astronomically small" that something like this would hit us so I imagine there's factors not being considered here
How often do we play this game?
How often would it hit something we care about on the dartboard?
How often would it hit something we care about on the dartboard?
You can browse recent approaches at:
https://cneos.jpl.nasa.gov/ca/
To isolate to really near stuff, choose +/- 30 days, and Nominal distance <= 1LD (lunar distance).
The asteroid in OP is linked to here: https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2019%20OK -- there's an orbit diagram.
https://cneos.jpl.nasa.gov/ca/
To isolate to really near stuff, choose +/- 30 days, and Nominal distance <= 1LD (lunar distance).
The asteroid in OP is linked to here: https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2019%20OK -- there's an orbit diagram.
The interactive 3D orbital graphic is great for visualizing the orbits and how they cross the Earth's path.
If this sort of thing concerns you, you might want to consider supporting this organization:
https://b612foundation.org
https://b612foundation.org
I honestly think we have bigger problems right now, like spending money on ways to reduce greenhouse gasses. We need to develop alternatives to non-renewables and, until we can use the alternatives, work on removing the gasses from the atmosphere.
Putting my money where my mouth is: I've been looking into this and as soon as I get my credit card (to be able to pay, I've never needed a CC before), I will sign up with https://climeworks.com to recapture some of my CO2. They seem to be one of the few that are actually capturing right now, so the money will be used for real capture, not just R&D that might yield results in the future. But to spread the risk, I am also going to spend money on the more traditional method of planting trees (which company is TBD, I have yet to find one that actually guarantees that they (or the locals) won't rip the tree out before it had a chance to capture its promised CO2). On the reduction side, I travel to work by public transport, work from home (it stays naturally cool) instead of using our office air conditioning unit, have a 100% renewable energy contract at home, etc.
Putting my money where my mouth is: I've been looking into this and as soon as I get my credit card (to be able to pay, I've never needed a CC before), I will sign up with https://climeworks.com to recapture some of my CO2. They seem to be one of the few that are actually capturing right now, so the money will be used for real capture, not just R&D that might yield results in the future. But to spread the risk, I am also going to spend money on the more traditional method of planting trees (which company is TBD, I have yet to find one that actually guarantees that they (or the locals) won't rip the tree out before it had a chance to capture its promised CO2). On the reduction side, I travel to work by public transport, work from home (it stays naturally cool) instead of using our office air conditioning unit, have a 100% renewable energy contract at home, etc.
It's called B612 Foundation and not a single reference to the Little Prince on the homepage besides the name? Weird.
Yeah, there is an explanation, but it's well hidden:
https://b612foundation.org/ever-wondered-where-the-name-b612...
https://b612foundation.org/ever-wondered-where-the-name-b612...
I imagine without early and widespread warning, an asteroid impact could be mistaken by nation-states for an attack. What safeguards (if any) might we have or develop to prevent an asteroid hitting country 1 from causing a “counter” strike by country 1 against country 2?
Very unlikely that China, Russia, or US (and its allied countries) would misidentify a nuclear attack. There are massive surveillance resources dedicated toward atmospheric sampling, etc. etc. and a non-nuclear explosion would be correctly identified as such in very short order.
On top of that, even a 30-meter asteroid impact would release more energy on impact than a typical nuclear warhead. A 250-meter asteroid might release more energy than ALL nuclear weapons used in the world to date.
On top of that, even a 30-meter asteroid impact would release more energy on impact than a typical nuclear warhead. A 250-meter asteroid might release more energy than ALL nuclear weapons used in the world to date.
Atmospheric sampling is definitive but slow, because it necessarily propagates at wind speed. I do agree misidentification is very unlikely.
They would identify initially using the global seismic network..
Would country 1 counter-strike without getting confirmation that it was, in fact, country 2? How would they know it wasn't country 3, 4, or 5?
If you ask what the known U.S. procedures and plans have been, the answer is a resounding YES, they would have nuclearly attacked ALL their enemies at once according to the man whose job was to evaluate these procedures and plans of the U.S. military:
https://www.bloomsbury.com/uk/the-doomsday-machine-978140888...
Just a sample quote:
"I soon discovered that in the plans of Pacific forces, from top to bottom, there was no provision at all for attacking only the Russian targets in their sphere. In every plan for war with the Soviet Union, Chinese targets (including every major city in China) were also struck."
In the whole book there are many accounts on that, on the various levels of the chain of command, even intentionally designed to act independently.
More transparency is still needed there, probably much less was changed in the following years than it ever admitted to any civilian, including the presidents, again according to the book, so the state is more than scary and when I read that insider info, I consider these involved really completely mad. Most of them Nazi-like "we just follow the orders" mad, and some simply pure evil mad.
https://www.bloomsbury.com/uk/the-doomsday-machine-978140888...
Just a sample quote:
"I soon discovered that in the plans of Pacific forces, from top to bottom, there was no provision at all for attacking only the Russian targets in their sphere. In every plan for war with the Soviet Union, Chinese targets (including every major city in China) were also struck."
In the whole book there are many accounts on that, on the various levels of the chain of command, even intentionally designed to act independently.
More transparency is still needed there, probably much less was changed in the following years than it ever admitted to any civilian, including the presidents, again according to the book, so the state is more than scary and when I read that insider info, I consider these involved really completely mad. Most of them Nazi-like "we just follow the orders" mad, and some simply pure evil mad.
I think apart from the energy release there are few similarities with a nuclear explosion (no EMP, no radioactive fallout) plus I have to imagine any air defense radar system could detect the incoming asteroid in its final moments.
This is a legitimate concern with the "young" nuclear powers, like India and Pakistan. Their detection technology is less mature; their command-and-control systems are less mature; there's a higher level of tension between the two. Neither country is incompetent or hungry for war, but it's worrying to me. I'd expect them to behave rationally, but if the timing happened to coincide with a particularly combative episode, things could get out of control. I'm not even going to speculate about how North Korea might react; they're a total wildcard.
This is just alarmist. The bravado shown on TV is surely not taken seriously by the authorities themselves for they know the consequences. So even if the point of impact coincides with the crescendo of tension to the T, sanity will prevail despite it seeming otherwise.
That is a very naive point of view. You don't know that their systems are "less mature". And do you really think thousands of seasoned scientists on both sides are going to misclassify any such event?
Not sure, but that scenario does sound like a interesting plot for a book or movie.
Niven and Pournelle thought so as well when they wrote "Lucifer's Hammer" [1] in which "...China, anticipating the coming ice age launches a preemptive nuclear attack on Russia. The last Soviet Premier reassures the US that they are not the target, and he requests help against the unprovoked attack."
[1] https://en.wikipedia.org/wiki/Lucifer%27s_Hammer
[1] https://en.wikipedia.org/wiki/Lucifer%27s_Hammer
Major nuclear powers all operate satellite based infrared launch detection systems. A rocket launch is a very unique thermal signature. I imagine China and Russia have satellites watching the north Dakota icbm fields, and vice versa.
One big safeguard is that no launch would be detected?
Failure to automatically launch the missiles.
In that case that might even be planned incompetence.
In that case that might even be planned incompetence.
Second asteroid hitting country 2
And of course, causing a counter-counter strike from country 2 against country 1. Messy!
[deleted](3)
Also, it really could be an attack. It's within the realm of plausibility for country 1 to launch a nudging vehicle to push a space rock into a collision course with country 2.
Eh maybe. It strains plausibility. We can't even accurately predict where deorbiting satellites will end up... It's pretty hard to imagine a nudge with the required delta-V and accuracy to hit a specific nation. Too far away and you get too much uncertainty, too close and you don't have enough dV for the push. Even if it could be done with today's technology, the potential for error is high, and if you screw up, you've accidentally started another war or "bombed" your own country. Can't imagine that a military with the requisite technology to pull this off wouldn't be able to think of a less-risky way to obliterate their enemy.
”We can't even accurately predict where deorbiting satellites will end up...”
I think that’s because they are so small. The impact of earth’s atmosphere on a 100m solid rock will be negligible in comparison.
Their speed perpendicular to earth also is very low, meaning they spend more time in the athmosphere. I guess they may even bounce of it a couple of times. If so, computing impact location requires calculating how many times a skipping stone will skip.
(But no, I don’t think we have the technology to make this an effective weapon. I would go for that rail gun on the moon instead. Still not quite within reach, but it would be a lot easier to get targeting accuracy)
I think that’s because they are so small. The impact of earth’s atmosphere on a 100m solid rock will be negligible in comparison.
Their speed perpendicular to earth also is very low, meaning they spend more time in the athmosphere. I guess they may even bounce of it a couple of times. If so, computing impact location requires calculating how many times a skipping stone will skip.
(But no, I don’t think we have the technology to make this an effective weapon. I would go for that rail gun on the moon instead. Still not quite within reach, but it would be a lot easier to get targeting accuracy)
[deleted]
JPL Horizons is awesome for this.
You can easily obtain the information on your own using the ephemerides at https://ssd.jpl.nasa.gov/horizons.cgi#top :
- minimum distance of 71350 km (44,334 miles vs 45,360 in article)
- Speed around 24.5 km/s (15.2 miles/sec vs 15 in article)
- Closest on july 25 at 01:21 UTC
Here's a rendering of the trajectory of the asteroid and the moon in july to get an idea of how close it came (moon orbits around 384,000 km from earth): https://imgur.com/a/3JaakFJ
- minimum distance of 71350 km (44,334 miles vs 45,360 in article)
- Speed around 24.5 km/s (15.2 miles/sec vs 15 in article)
- Closest on july 25 at 01:21 UTC
Here's a rendering of the trajectory of the asteroid and the moon in july to get an idea of how close it came (moon orbits around 384,000 km from earth): https://imgur.com/a/3JaakFJ
The original article (https://www.washingtonpost.com/nation/2019/07/26/it-snuck-up...) includes links to some interesting background information, including the event leveling a huge forest area. And it correctly uses square km/miles instead of "square acres".
For those interested, you can watch Joe Rogan's podcast with Randall Carlson on this topic: https://www.youtube.com/watch?v=R31SXuFeX0A
The likelihood it would hit a highly populated area is still incredibly slim even if it did strike earth. I wonder if there are some smaller asteroids on rare occasions just landing in the ocean that we don't really know about.
The distribution of orbits, and hence strikes, is an interesting problem.
Here is a plot of population against latitude:
https://www.themarysue.com/world-population-latitude-longitu...
I assume a bias to the ecliptic, hence the area within the tropics is more likely to get hit. Big spikes for Jakarta, Dhaka, Shanghai/PRD, Delhi/Mumbai/Karachi/Lahore, Kinshasa, Lagos ...
I also suppose you could attack the problem in two ways: historical strikes (confounded by erosion, tectonics and subduction), and orbital statistics, perhaps weighted by asteroid size.
Anyone have refs for this?
Here is a plot of population against latitude:
https://www.themarysue.com/world-population-latitude-longitu...
I assume a bias to the ecliptic, hence the area within the tropics is more likely to get hit. Big spikes for Jakarta, Dhaka, Shanghai/PRD, Delhi/Mumbai/Karachi/Lahore, Kinshasa, Lagos ...
I also suppose you could attack the problem in two ways: historical strikes (confounded by erosion, tectonics and subduction), and orbital statistics, perhaps weighted by asteroid size.
Anyone have refs for this?
So here's what I was wondering for quite some time: if, let's say, hypothetically, there were an object approaching Earth at nearly the speed of light, is there any way in our frame of reference to even detect it?
And is it possible for such an object to exist in our universe, and if not, why?
The math seems to work out such that the object the size of a US quarter (5.67g) at 0.999 C will have a relativistic kinetic energy around 2.6MT of TNT.
And is it possible for such an object to exist in our universe, and if not, why?
The math seems to work out such that the object the size of a US quarter (5.67g) at 0.999 C will have a relativistic kinetic energy around 2.6MT of TNT.
If something travels nearly the speed of light we couldn’t detect it. Any kind of information from this object would at maximum travel at the speed of light so this information would arrive only a little sooner.
Asking for a friend, is it not possible to park phased array satellites out at 43,000 KM orbit looking for faint smaller asteroids with current technology?
Technically, yes. Politically? We don't use the word sense with politics.
I might be wrong, but in a previous comment [0] a few days ago I noted that the asteroid composition is mostly ice, which means it should be much less dangerous than a "rock".
[0]: https://news.ycombinator.com/item?id=20508618
[0]: https://news.ycombinator.com/item?id=20508618
Similary, the Seattle Post writes:
> Lakdawalla said that while the asteroid’s close brush with Earth may have sparked some concern, “it is zero percent danger to us. It’s the kind of thing where you learn about something that you didn’t know about, like things flying close by us, and your inclination is to be scared,” she said. “But just like sharks in the ocean, they’re really not going to hurt you and they’re really fascinating to look at.”
> Lakdawalla said that while the asteroid’s close brush with Earth may have sparked some concern, “it is zero percent danger to us. It’s the kind of thing where you learn about something that you didn’t know about, like things flying close by us, and your inclination is to be scared,” she said. “But just like sharks in the ocean, they’re really not going to hurt you and they’re really fascinating to look at.”
Planetary defense from Planetary Society if you want to help or participate http://www.planetary.org/explore/projects/planetary-defense/
Sir Arthur Clarke describes the impact itself nicely in Rama intro: https://youtu.be/yMPA25SGlpA?t=88
As I understand, the mayor threat is the dust which doesn't settle for many months. This could starve world's population and pose a major existential risk. Maybe we can use our spy satellite network and just turn all sensors outwards?
As I understand, the mayor threat is the dust which doesn't settle for many months. This could starve world's population and pose a major existential risk. Maybe we can use our spy satellite network and just turn all sensors outwards?
I have no reason to doubt this story - that it caught everyone by surprise. But if such an asteroid was discovered in advance and it was determined we were at high risk of being hit, I'm not so sure the public at large would be notified in every circumstance. If the impact would be large enough and/or the warning short enough, getting people panicky might do more harm than good.
The problem with this idea is that it rests on two incorrect assumptions - that there is some governing body that would be able to prevent the release of such information, and that we would immediately know upon detection that the asteroid was on a collision course.
In fact, in this case, the asteroid was detected independently by the SONEAR survey in Brazil and the ASAS-SN telescope network run by Ohio State University. Neither of these would fall under the "jurisdiction" of NASA or any governmental organization that would effectively be able to prevent them from talking about it. ASAS-SN tweeted the discovery, and I'm quite sure they didn't have to ask anyone permission to do so.
Secondly, the first few observations of a newly-discovered near-Earth object are generally not enough information to calculate the object's orbit accurately enough to know if it will hit Earth or not. So what do scientists do when they discover one? They immediately report it to the IAU and get the word out to as many other astronomers as possible, in order to obtain more observations & accurately determine the orbit.
As a result, it's hard to imagine how such a discovery could be kept secret.
In fact, in this case, the asteroid was detected independently by the SONEAR survey in Brazil and the ASAS-SN telescope network run by Ohio State University. Neither of these would fall under the "jurisdiction" of NASA or any governmental organization that would effectively be able to prevent them from talking about it. ASAS-SN tweeted the discovery, and I'm quite sure they didn't have to ask anyone permission to do so.
Secondly, the first few observations of a newly-discovered near-Earth object are generally not enough information to calculate the object's orbit accurately enough to know if it will hit Earth or not. So what do scientists do when they discover one? They immediately report it to the IAU and get the word out to as many other astronomers as possible, in order to obtain more observations & accurately determine the orbit.
As a result, it's hard to imagine how such a discovery could be kept secret.
>The problem with this idea is that it rests on two incorrect assumptions - that there is some governing body that would be able to prevent the release of such information, and that we would immediately know upon detection that the asteroid was on a collision course.
Not necessarily. Only a couple people knew about this one before it had whizzed by. While I agree it'd be impossible to keep an upcoming impact secret, if the timeframe is short enough it would only take a few select people to keep it contained long enough to no longer matter.
And choosing to keep it secret wouldn't only be done if collision was known to be certain. Just having a moderate chance of impact might be enough.
Not necessarily. Only a couple people knew about this one before it had whizzed by. While I agree it'd be impossible to keep an upcoming impact secret, if the timeframe is short enough it would only take a few select people to keep it contained long enough to no longer matter.
And choosing to keep it secret wouldn't only be done if collision was known to be certain. Just having a moderate chance of impact might be enough.
on another hand, if you see a gamma-ray-burst heading this way, duck and cover... https://www.youtube.com/watch?v=8HvwNOSnveE
I mean that’d be near instant vaporization wouldn’t it? For some reason that makes me less scared about it since you wouldn’t really know what’s happening before it’s all over
No, according to the video gamma ray burst means increase in UV potentially damaging DNA of phytoplankton, global cooling due to NO2 solar energy reflection.
It'll be pretty slow, but at a large scale.
It'll be pretty slow, but at a large scale.
Your comment made me think of whether a GRB could have caused the cambrian explosion. So I searched for that and found this paper:
https://arxiv.org/abs/1403.7303
https://arxiv.org/abs/1403.7303
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I am surprised with the talk about optical visibility. Are there no radars deployed for scanning the skies?
Because these objects are moving fast, you would need to look a long way out. Long range radar is hard because the inverse square law applies in both directions, so you need 16x the power to double the range.
Maybe a solar powered array on the dark side of the Moon, to restrict any interference from Earth systems, and you get a nice sweep of the ecliptic for free.
So it was set to stun, not to kill?
duplicate thread see https://news.ycombinator.com/item?id=20537941
Doesn't it vindicate the we need to weaponize space?
Not really, because space weapons inevitably lead to at the very least space weapons testing, and most likely space combat. Space combat creates space junk, which prevents us from going to space in the future, which prevents us from detecting and deflecting asteroids.
You might think "well, we just need to find ways to destroy space junk" but unfortunately (almost?) all tools useful for destroying space junk can also be used to destroy perfectly functional objects in space, and therefore count as space weapons, which lead to space junk...
You might think "well, we just need to find ways to destroy space junk" but unfortunately (almost?) all tools useful for destroying space junk can also be used to destroy perfectly functional objects in space, and therefore count as space weapons, which lead to space junk...
I still think someone tried to redirect its path and made a minor mistake in their calculations ;)
It's too bad the "space force" isn't setup just for this.
Scientists are already searching for and tracking such objects. More funding would be nice but we definitely don't need the US to break more treaties in order for the world to track NEOs.
Who really cares about the space treaty?
It'd be nice to have a well-funded group that has 'making sure no asteroids hit us' as part of its motto
It'd be nice to have a well-funded group that has 'making sure no asteroids hit us' as part of its motto
Russia and China would create a space force if the US did...
Maybe we should create a world anti-asteroid space force...
I meant just as in exclusively for this. And what is the point of tracking them if we don't plan to do anything about them?
An asteroid on collision course will not be seen. I just realized an old concept applies here. When two objects are on a collision course with each traveling in a straight line, the apparent heading toward one as viewed from the other does not change. In other words, when a deer runs in front of a car, the angle to the deer doesn't change - it just gets bigger as you close in, but position in your field of view doesn't change.
Astronomers look for things moving against the background sky, but over a short enough time span (maybe a few days) the earth and an asteroid are moving almost in straight lines. That means all you'd see is a speck of light that gets brighter as it gets closer, but does not appear to move against the distant background stars.
Has anyone quantified this phenomenon with respect to asteroid hunting?
Astronomers look for things moving against the background sky, but over a short enough time span (maybe a few days) the earth and an asteroid are moving almost in straight lines. That means all you'd see is a speck of light that gets brighter as it gets closer, but does not appear to move against the distant background stars.
Has anyone quantified this phenomenon with respect to asteroid hunting?
This would be true if the asteroid and the earth are both points. Obviously, they aren't. An observing scientist would not see it this way unless it were heading directly for them.
>> An observing scientist would not see it this way unless it were heading directly for them.
That was my point exactly. An asteroid heading directly towards us will not appear to be moving against the background. If that movement is required in their detection methods, it will fail for the most dangerous ones.
That was my point exactly. An asteroid heading directly towards us will not appear to be moving against the background. If that movement is required in their detection methods, it will fail for the most dangerous ones.
I'm not an expert, but I imagine that astronomers are pretty good at determining brightness of objects. And space stuff moves in orbits anyway.
I suspect that astronomers are using exactly this principal to search for NEOs.
It scrapes the JPL data hourly, and it’s satisfying when it picks up these close passes discovered at short notice:
https://twitter.com/lowflyingrocks/status/115420008580852531...