Near Earth Asteroid 'Florence' Makes a Close Pass (space.com)

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Near Earth Asteroid 'Florence' Makes a Close Pass (space.com)

Posted by BeauHD on Sunday September 3, 2017 @04:22PM from the sprit-in-the-sky dept.

kbahey writes: A big, bright, near-Earth asteroid, known as 3122 Florence, made a safe fly by Friday night. Florence is classified as a Potentially Hazardous Object. At its closest, it was about 7 million km (4.4 million miles) away from earth. It is still visible in amateur telescopes over the next few days where it would be seen to move over several minutes against the background stars. It can be located using this map. According to NASA officials, the asteroid hasn't been this close to Earth since 1890, and it won't be this close again until 2500. "Asteroid 3122 Florence was discovered in 1981 by astronomer Schelte 'Bobby' Bus at the Siding Spring Observatory in Australia," reports Space.com. "The asteroid is named in honor of Florence Nightingale (1820-1910), who pioneered modern nursing, NASA officials said in a separate statement."

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That's nothing... by __aaclcg7560 · 2017-09-03 16:32 · Score: 1

An asteroid buzzed the Earth at 50,000 miles away last year.
https://www.space.com/33891-newfound-asteroid-buzzes-earth-2016-qa2.html
1. Re:That's nothing... by ls671 · 2017-09-03 16:46 · Score: 2
  
  I might have read your link too quickly but anyway; what strikes me in those kind of reports is that they don't mention the relative speed of the object with Earth as a reference and this plays a big role in the amount of energy released should an impact occur.
  
  --
  Everything I write is lies, read between the lines.
2. Re:That's nothing... by Anonymous Coward · 2017-09-03 19:05 · Score: 1
  
  No, creimer, having facts is not being "bitter". Gaining weight after a month of your much-hyped "low carb" diet is a bitter pill to swallow, though.
3. Re:That's nothing... by DontBeAMoran · 2017-09-03 23:47 · Score: 1
  
  When you get hit by a bus it doesn't really matter if it's going at 250 km/h or 2500 km/h.
  
  --
  #DeleteFacebook
4. Re:That's nothing... by rgbatduke · 2017-09-04 00:40 · Score: 4, Informative
  
  Asteroids will hit the Earth (if at all) at LEAST at 11.2 km/sec, as they have greater than escape energy relative to the Earth's gravitational field. That's 11.2 kilometers per SECOND, or a bit over 40,000 kilometers per HOUR. The energy released is greater than 64 million joules per kilogram of rock (escape energy). So if you take a (say) 2.5 km ball of rock (5 km in diameter), roughly estimate its mass as 4 times r^3 you get 4 e+18 joules. Convert this to tons of TNT and you get roughly a teraton. The total explosive energy of the entire nuclear arsenal of the Earth is less than 7 gigatons (including reserve weapons -- only around 1 GT is on delivery vehicles almost all of this belonging to the US and Russia). The biggest explosion in recorded history was the explosion of Tambora in 1815, estimated at 33 GT. This is then equivalent in crude terms to over 100 times the entire global arsenal nuclear and conventional, or over 30 times the explosive power of the largest explosion in recorded history, one that altered global climate for close to a decade. Or GREATER.
  I'm not sure "hit by a bus" is an apropos metaphor.
  
  --
  Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
5. Re:That's nothing... by __aaclcg7560 · 2017-09-04 03:47 · Score: 1
  
  No, creimer, having facts is not being "bitter".
  That my trolls have trolls is funny.
  
  Gaining weight after a month of your much-hyped "low carb" diet is a bitter pill to swallow, though.
  If losing weight was so simple, there wouldn't be overweight people and self-righteous pricks to condemn them.
6. Re:That's nothing... by __aaclcg7560 · 2017-09-04 04:07 · Score: 1
  
  You cured diabetes in six months by diet, remember?
  No. My father went off of insulin shots after being on a low-carb diet for six months. He wasn't cured of diabetes. Diet and exercise kept his diabetes in control.
  
  And by self-righteous, do you mean like someone who ignores diet advice from people who weigh 180 pounds?
  Self-righteous as in if I'm not doing weight loss their way I must be doing it wrong then.
7. Re:That's nothing... by __aaclcg7560 · 2017-09-04 04:55 · Score: 1
  
  And since you keep getting fatter, you are doing it wrong.
  
  Wrong. I made a change in my diet, it didn't work, and, since I reversed that change, I'm losing weight again.
  
  Either get some help, or keep getting fatter and failing again.
  Only an idiot gets help on Slashdot.
8. Re:That's nothing... by pixelpusher220 · 2017-09-04 05:05 · Score: 1
  
  isn't escape velocity relative to distance though? Since gravity is greater in proximity, it would follow that something 4.4 million miles away doesn't need the speed that something 25,000 miles away would need.
  
  Actually a serious question, I don't know.
  
  --
  People in cars cause accidents....accidents in cars cause people :-D
9. Re:That's nothing... by __aaclcg7560 · 2017-09-04 05:06 · Score: 1
  
  Or, you know, don't follow this advice, and keep fucking your health up for the next few years left to you.
  I've lost 13 pounds since I got my digital weight scale. I made changes to my diet that didn't work, and, now that I reversed that change, I'm losing weight again. My system is working just fine.
10. Re:That's nothing... by DidgetMaster · 2017-09-04 07:04 · Score: 1
  
  Not only that but the MASS of the object is also important. Little rocks or grains of sand hit our atmosphere all the time going thousands of miles per hour (we call them shooting stars). I think it has to be about the size of a basketball before it has a chance of actually striking the ground before burning up.
11. Re:That's nothing... by ls671 · 2017-09-04 07:58 · Score: 1
  
  The mass is important but with a big enough mass, the speed becomes much more important since the kinetic energy varies to the square of the speed:
  E = 0.5*m*v*v
  
  --
  Everything I write is lies, read between the lines.
12. Re: That's nothing... by __aaclcg7560 · 2017-09-04 09:38 · Score: 1
  
  You lost 13 pounds to get to 357, then gained 3 pounds back because your bullshit wasn't working. That's a total loss of ten pounds, creimer.
  I'm back at 357 pounds. A total loss of 13 pounds.
13. Re:That's nothing... by angel'o'sphere · 2017-09-04 09:51 · Score: 1
  
  Escape velocity is relevant for launching somthing into orbit, or to escape to outer space. Hence the name.
  It has nothing to do at all with the potential speed of an impacting body!
  
  --
  Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
14. Re:That's nothing... by angel'o'sphere · 2017-09-04 10:01 · Score: 1
  
  You are an idiot.
  Your lunch plan makes no sense at all.
  If you want to starve one to lose weight, you give him enough to drink to get the vital vitamins and trace elements.
  Letting him eat salad over salad makes no sense at all ...
  Your stupid idea of weighting food in the kitchen, wow, how helpfull is that to a person that actually is nit eating much but is a super good converter of energy?
  If you want to 'help' Creimer, you should for funk sake read one of the first posts where he mentioned his weight.
  And if you look at his pictures: sure he is more heavy than me, but unhealthy overweigh? I don't think so!
  
  --
  Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
15. Re:That's nothing... by Hognoxious · 2017-09-04 11:02 · Score: 1
  
  with a big enough mass, the speed becomes much more important
  
  Why does the relative importance change? Is there some slider control that trades one for the other?
  
  --
  Confucius say, "Find worm in apple - bad. Find half a worm - worse."
16. Re:That's nothing... by Hognoxious · 2017-09-04 11:07 · Score: 1
  
  Why is escape velocity relevant? Are we chucking the bloody things into space? I was under the impression that they're moving the other way...
  And this got to +4 informative?
  
  --
  Confucius say, "Find worm in apple - bad. Find half a worm - worse."
17. Re:That's nothing... by ls671 · 2017-09-04 11:28 · Score: 1
  
  As another poster has mentioned, small enough objects don't make it to the Earth surface due to the protection of the atmosphere. I assume they just disintegrate faster the greater the speed.
  Also, to further illustrate the formula I posted, if the mass is 8 times greater you get 8 times more energy but if the relative speed to Earth is 8 times greater you get 64 times more energy and it is even more than that if the object travels at a considerable fraction of the speed of light relative to Earth. The formula I posted is only valid for small fractions of the speed of light.
  https://en.wikipedia.org/wiki/...
  
  --
  Everything I write is lies, read between the lines.
18. Re: That's nothing... by __aaclcg7560 · 2017-09-04 14:16 · Score: 1
  
  The information and the help is out here - you just have to be willing to take it.
  The same information that I'm already using to lose 13 pounds. I'm already down two pant sizes and my newest pants is starting to feel loose. But because I'm not doing it your way, I must be doing it wrong.
19. Re:That's nothing... by ColaMan · 2017-09-04 17:01 · Score: 1
  
  Escape velocity is the minimum velocity you need to completely escape Earth's pull. So if you you're on the Earth's surface, and you impart a velocity of 11km/s to an object, it will juuuuuuuust escape Earth's sphere of influence.
  Similarly if you have an object in space that is juuuuuust within Earth's sphere of influence and it gets pulled in, it will have a velocity of at least 11km/s by the time it reaches the surface.
  "At least" being the operative term there, because the object could already be heading towards Earth, in which case it will end up going at least 11km/s faster.
  
  --
  
  You are in a twisty maze of processor lines, all alike.
  There is a lot of hype here.
20. Re:That's nothing... by rgbatduke · 2017-09-05 00:23 · Score: 1
  
  So here's a serious answer. Gravitational potential energy has the form U = -GMm/r where r is the distance from the center of the earth. Practically speaking, this means that a kilogram of mass sitting on the surface of the Earth has a gravitational potential energy of -GMm/R where R is the radius of the earth and m = 1. If you work out the arithmetic, this is NEGATIVE 64 MJ give or take a hair (GM/R = gR = 6.4x10^7 J).
  Total energy is potential energy plus kinetic energy: E = K + U with K = 1/2 mv^2. If you are "infinitely" far from Earth and at rest relative to the Earth, the kilogram of mass has a total energy of zero. Energy is conserved, so as it falls towards Earth (gravity doing work on it to speed it up) its potential energy decreases (because more negative) and its kinetic energy, which is strictly non-negative, increases in order that the total energy REMAINS zero. When it hits, therefore:
  K = -U = 64x10^7 J = 64 MJ
  "Infinity" here is just any distance that is very large relative to the radius of the Earth so that U is "small" relative to this collision energy and hence an unimportant correction.
  Note well that nothing stops our kilogram of mass from being THROWN in from infinity with MORE than zero initial kinetic energy. Indeed, we expect falling asteroids to nearly always start with some speed relative to the Earth and a total energy relative to the Earth GREATER than zero, as they are "unbound" by Earth gravity and in what is called a hyperbolic trajectory when they hit. This means that if they miss, they keep on going and don't eventually come back or end up trapped in orbit around the Earth. It also means that they can hit with a kinetic energy strictly greater than 64 MJ or (solving for the speed of the collision) a speed strictly greater than 11.2 km/sec.
  If you really want to understand this further, here is a physics book where it is explained, between chapters 3, 4 and 12:
  http://www.phy.duke.edu/~rgb/C...
  rgb
  
  --
  Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
21. Re:That's nothing... by rgbatduke · 2017-09-05 00:38 · Score: 1
  
  You are (I think) confused and have this backwards. We consider how much energy/speed we have to give something to throw it up to arrive, at rest, at a maximum height of e.g. 25,000 miles (which is the energy/speed it will have if it lands when dropped from there, at rest. To throw it up HIGHER you have to throw it FASTER with MORE energy. Gravitational POTENTIAL ENERGY is actually LESS in proximity -- greater in magnitude but (by convention) MORE NEGATIVE.
  Specifically, if we drop one kilogram from rest 25,000 miles away -- say 6 Earth radii (R_e \approx 4000 miles) then its initial total energy is E_i = U(R_e)/6 or
  E_i = U(R_e)/6 \approx -10 MJ = K_f + U(R)
  When it lands, energy is conserved, so:
  E_f = E_i = K_f + U(R_e) = - 10 MJ
  K_f = E_i - U(R_e)
  Or it hits with 54 MJ instead of 64 MJ
  4.4 million miles is so many that E_i = U(R_e)/1100 \approx - 64 KILOjoules per kilogram. Then:
  K_f = E_i - U(R_e) \approx 64 MJ, the initial total energy is so small it doesn't change either of these digits or (for that matter) the next two. 4.4 million miles is "infinity" as far as this estimation is concerned.
  
  --
  Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
22. Re:That's nothing... by rgbatduke · 2017-09-05 00:50 · Score: 1
  
  You are mistaken. Escape velocity has nothing to do with launching something into orbit. Well, yes it does. One has to add half of escape energy to an object as kinetic energy to establish it in a low, circular orbit, but that is more or less an interesting algebraic coincidence (related to the virial theorem). Furthermore, as I work out algebraically above, escape speed IS EXACTLY the speed of an object with escape energy, and is in turn BY DEFINITION the speed of an object dropped from infinitely far away, initially at rest. You can learn all of this from literally any decent introductory physics textbook, from any teacher of physics (including me:-), and probably from wikipedia. I already cited the intro physics textbook I wrote above, so you can learn it there, but since you are arguing with me you might understandably refuse to accept that is is authoritative -- I might be a nut instead of somebody who has been teaching intro physics for just about 40 years. So go find one of your own, or google "escape velocity" or "escape speed".
  
  --
  Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
23. Re: That's nothing... by Anonymous Coward · 2017-09-05 00:54 · Score: 1
  
  The same information that I'm already using to lose 13 pounds.
  Yes, lose 13 pounds, and then stick there indefinitely, because 13 pounds ought to be enough for anybody.
  
  I'm already down two pant sizes and my newest pants is starting to feel loose.
  Bullshit. Just, bullshit. Even if every pound you lost was *right under your belt*, you wouldn't be "feeling loose" and going for 3 pant sizes down.
  
  But because I'm not doing it your way, I must be doing it wrong.
  No, because you're not losing weight you must be doing it wrong. The information was there long before the past 17 weeks creimer- why did it take you 48 years to figure out how to lose 13 pounds? Why did it take you 13 weeks to lose 13 pounds, and then you bounced up and down and ended up with a net zero in the last 4 weeks?
  Ultimately, I don't care if you "do it my way" - but if you honestly want to lose weight, then you have to honestly admit to yourself that your way is. not. working. It hasn't worked in the last 48 years, it apparently worked for 13 weeks, through the peak of the summer, and probably represents mostly water weight that you sweated out, and now you're back to a net-zero lifestyle, still claiming 1500 calories and a 2500 bmr.
  Whenever you reach the point where you're willing to admit that your "plan" isn't working - probably around the time you end up hospitalized for an emergency bypass - just let me know - I'll be here to help. The information and the help is out here, you just have to be willing to take it.
24. Re:That's nothing... by rgbatduke · 2017-09-05 04:48 · Score: 1
  
  So, you didn't bother to read any of the other two or three posts where I worked out the algebra (face-palm) before spouting crap. No, asteroids cannot hit "at any speed imaginable". They can hit at any speed that is GREATER THAN OR EQUAL TO Earth's escape speed, as I actually discussed and derived. Also, escape speed FROM EARTH is relative TO EARTH. So yes, I absolutely neglected solar potential energy because it just doesn't vary that much across the range where most of the actual acceleration of an object falling to Earth occurs -- inside lunar orbit. I'm not a "self-proclaimed" physics teacher, by the way. I just finished teaching university level calculus based introductory E&M to physics majors this morning, and will be teaching intro level mechanics to engineering students this afternoon.
  You might also look at the post that I actually replied to, which suggested that they could land at 250 or 2500 kilometers PER HOUR. No, they can't. Yet your "knowledgeable" post implies that they can, to quote: "An asteroid can hit earth with any imaginable speed." Any imaginable speed faster than Earth's escape speed, 11.2 km/second, precisely as I replied. You can see the capitalized AT LEAST in the reply without even bothering to read the whole thing or read the wikipedia article on escape velocity:
  https://en.wikipedia.org/wiki/...
  where they do EXACTLY the same general algebra I do in my replies above, leading to the same general conclusion, before sure, going off to discuss escaping from the sun or wherever. "Escape energy" is zero total energy for forces that drop off like 1/r^2 (or technically, faster than 1/r), a definition that holds for Coulomb's Law and electrostatics as well. Orbits are categorized as elliptical (bound, E_tot less than 0), parabolic (E_tot = 0) or hyperbolic (E_tot great than 0) in all physics or astronomy textbooks, and yes, these are all defined in this way with respect to the specific two-body interaction involved in introductory treatments simply to avoid many body difficulties, just as they are almost invariably discussed in the limit where one body is much more massive than the other to avoid reduced mass coordinates and other difficulties.
  As for adding relative velocities as you seem to have attempted to do -- it doesn't actually work that way, because the expressions that occur in the energy conservation equation are non-linear. Otherwise you would be right, one could somehow "drop" an asteroid in some way that lands at zero speed. What you mean to do is to compute the initial total mechanical energy of the dropped mass at any point in its free or bound trajectory, and compute its final mechanical energy as it is moving the the same velocity as the target object e.g. the Earth (or even pickier, the same velocity as the part of the Earth's surface it inelastically collides with, although this speed of roughly 1000 mph or less is pretty negligible relative to Earth escape speed). The difference has turned into "heat" during the collision. But since kinetic energy scales like velocity squared, and potential energy scales like 1/r (from each center being considered, most likely the Earth and the Sun if you want to talk about solar orbits and are willing to neglect other objects) it is absolutely not as simple as just adding relative velocities and is complicated further still if the object falling to Earth starts in a solar bound orbit. There is a nice equation for this in the Wikipedia article you are refusing to read although the discussion of the point is a bit abbreviated and isn't quite correct either, more of an approximation (note its "under simplified assumptions").
  Anyway, if you want to (how was it you put it?:-) "make a fool of yourself" by looking a few things up and spouting nonsense, hey, bring it. Seriously, dude -- actual physics Ph.D. and everything, teaching intro physics since 1977, wrote my own textbooks, don't even bother with lecture notes because I just plain know this stuff and can lecture on any topic at the intro level at least cold. So bring it.
  
  --
  Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
25. Re:That's nothing... by dmgxmichael · 2017-09-05 06:29 · Score: 1
  
  I guess amend that to "hit by a bus when you are a fly" ?
26. Re:That's nothing... by Trogre · 2017-09-05 13:32 · Score: 1
  
  So, Earth's atmosphere doesn't slow asteroids down, and therefore the minimum speed of an asteroid falling unimpeded from space is also the minimum speed needed to sling something back into space?
  Is that what you're saying?
  
  --
  "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
27. Re:That's nothing... by rgbatduke · 2017-09-06 08:33 · Score: 1
  
  "Earth" slows asteroids down when they land on it. To rest, in the Earth's rest frame, in reasonable approximation. This is a completely inelastic collision, and given the disparity in their masses nearly all of the asteroid's relative kinetic energy is transformed into heat. Some of that heat heats the atmosphere as the atmosphere lands, sure, but seriously, look at the magnitudes involved. This is pretty much irrelevant, given that the impact is going to blow the friction-heated atmosphere near the impact point clean off of the planet.
  As far as the second part of your question is concerned, yes, energy is conserved, so the minimum speed of an asteroid falling unimpeded from a place very far from Earth is also the minimum speed required to throw it back up to that place.
  This isn't that radical an idea, after all. It works just fine for baseballs. If you drop a baseball in a vaccuum so that it falls some distance H, it will arrive with a speed of roughly \sqrt{2 g H} in near-Earth gravity g. If you want to throw it so that it rises to a maximum height H, you have to throw it up with speed \sqrt{2 g H}. This is simple algebra:
  E_tot = U = mgH = 1/2 m v^2 = K
  Solve for v. The solution doesn't care if v is directed up or down -- both are consistent with it having EITHER started at H and fallen to 0 (v negative or down) or started at 0 and risen to H (v positive or up). Or you can do the simple solution to Newton's second law and get there a bit harder from:
  Falling: y(t) = H - 1/2 g t^2 and v(t) = - g t
  vs
  Rising: y(t) = v_0 t - 1/2 g t^2 and v(t) = v_0 - gt
  If you solve the first for v when it hits the ground, you'll get \sqrt{2 g H}. If you use v_0 = \sqrt{2 g H} in the second one, it will rise precisely to height H and stop.
  But seriously, all of this is in any introductory physics textbook, including mine. Look, here's a nice little lecture on this. Note especially slide 6. Yes, escape speed is also drop from infinity from rest speed when considering two bodies, and at the intro level that's all one teaches. But the energy concepts work just fine for whole solar systems, even when solving the dynamics problems involved becomes nearly impossible for long times:
  http://www.phys.hawaii.edu/~mo...
  Otherwise, find a physics textbook. Mine is online and free, and if you google up answers you are as likely as not to get directed to it just because there aren't many free competitors, but I promise, it is accurate enough and fairly complete (except where there are, no doubt, little errors or missing stuff -- an online textbook is never quite finished, sigh:-). But if you prefer Tipler and Mosca, or Halliday, Resnick and Walker or Serway and Jewett or Young and Freedman (old Sears and Zemansky) or Giancoli or Knight (I'm just reading off the authors of the stacks of the damn things in my office) IT DOESN'T MATTER. Look, I'm an expert on this. No kidding. Not expert at the level of a cosmologist maybe, but at the intro level it just isn't that difficult, and on a good day I can actually solve Newton's Law of Gravitation in Newton's Second Law and show that planets really DO move in elliptical orbits, which is a notch or two past intro. So just as a very elastic ball, dropped from a height, will bounce back up to almost the same height (difference lost to heat and sound during the bounce), so a comet that comes into the sun and passes some distance away from the sun at some speed will have the SAME speed as it departs from the sun at that distance on the far side.
  
  --
  Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
28. Re:That's nothing... by RockDoctor · 2017-09-07 21:09 · Score: 1
  
  You and RGBatDUKE are talking at cross purposes.
  You :
  
  a) Escape velocity earth: 11.2 km/s
  b) earth orbit speed: 30km/s
  c) incoming asteroids speed: what ever you want. If it is e.g. "your escape velocity" and it comes retrograde into the earth, then it is 41 km/s
  Which is a different situation to RGB's :
  
  escape speed IS EXACTLY the speed of an object with escape energy, and is in turn BY DEFINITION the speed of an object dropped from infinitely far away, initially at rest
  Of course, if you complexify RGB's textbook situation by adding an initial velocity between the two objects - as you do, then you get the same answers.
  Textbooks leave that out for the first exercise. You're on the second exercise.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
29. Re:That's nothing... by RockDoctor · 2017-09-07 21:22 · Score: 1
  
  So, Earth's atmosphere doesn't slow asteroids down
  Not significantly. (Please note the word "significantly" in the phrase "not significantly".) The atmosphere is about 10km thick for the bottom half of it (by weight), which is traversed by an impactor in 0.9 seconds or less (see dispute surrounding ; rgbatduke is right). Even for something as small as a bullet, 0.9 seconds of atmospheric drag isn't sufficient to make them safe.
  For something like the Chixulub impactor (the so-called "dinosaur killer" ; see my signature), by the time that the whole impactor was in that bottom half of the atmosphere, the leading edge was starting the touchdown process. It was already plasma, but starting the touchdown.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
30. Re:That's nothing... by RockDoctor · 2017-09-07 21:25 · Score: 1
  
  Read rgbatduke's comments. He's right.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
31. Re:That's nothing... by Hognoxious · 2017-09-09 05:21 · Score: 1
  
  He's a fucking windbag and he has the communication skills of a mineral.
  
  --
  Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Timely by freeze128 · 2017-09-03 16:42 · Score: 1

If this asteroid is classified as a "Potentially Hazardous Object", then why is it being reported two days *AFTER* the pass?
1. Re:Timely by ls671 · 2017-09-03 16:51 · Score: 1
  
  Because we didn't want to cause mass panic. This is how things works out most of the time.
  
  --
  Everything I write is lies, read between the lines.
2. Re:Timely by lucm · 2017-09-03 17:11 · Score: 2
  
  Probably because most of the people who care were busy taking ecstasy at Burning Man
  
  --
  lucm, indeed.
3. Re:Timely by DontBeAMoran · 2017-09-03 23:49 · Score: 1
  
  Shit, it's already done? I better make the most of it and burn my arm hairs at home to simulate the missed experience.
  
  --
  #DeleteFacebook
4. Re:Timely by Hognoxious · 2017-09-04 01:47 · Score: 1
  
  And no stories from a frequent conributor about solving the ice problem? This site ain't what it used to be.
  
  --
  Confucius say, "Find worm in apple - bad. Find half a worm - worse."
5. Re:Timely by Toad-san · 2017-09-04 03:01 · Score: 1
  
  You say that like it's a bad thing :-(
  https://designyoutrust.com/201...
6. Re:Timely by Anonymous Coward · 2017-09-04 04:19 · Score: 1
  
  Too dangerous.
  Imagine the TFA-oid were still inbound.
  Some idiot post article on /.
  Suddenly it gets slashdotted.
  Asteroid becomes laggy and stops mid-space.
  Not only would a laggy/frozen asteroid annoy the astronomy community world-wide but it would also slowly start moving right towards earth - being pulled in by our gravity.
  Solution is simple: wait until it passed, most people will ignore asteroids that aren't inbound.
7. Re:Timely by angel'o'sphere · 2017-09-04 10:06 · Score: 1
  
  Which part of:
  4
  million
  miles
  away
  did you not get?
  I can easily translate that into kilo meters for you, if that helps. (You have a rough idea how far away the moon is, yes? Why do I have the feeling that you have no clue ... ? )
  
  --
  Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
So glad.. by Anonymous Coward · 2017-09-03 16:56 · Score: 4, Funny

"A big, bright, near-Earth asteroid, known as 3122 Florence, made a safe fly by Friday night."
So glad we didn't damage it. Those things can be expensive!
1. Re:So glad.. by K.+S.+Kyosuke · 2017-09-04 01:28 · Score: 1
  
  "near-Earth asteroid"
  That's not a euphemism for a green pleasure machine here, right?
  
  --
  Ezekiel 23:20
That makes perfect sense! by 93+Escort+Wagon · 2017-09-03 17:18 · Score: 1

Let's honor a woman who saved many lives by naming a rock big enough to cause a mass extinction event after her!

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#DeleteChrome
1. Re:That makes perfect sense! by drinkypoo · 2017-09-03 23:29 · Score: 1
  
  Let's honor a woman who saved many lives by naming a rock big enough to cause a mass extinction event after her!
  Yep, that was my biggest takeaway from the summary, too. If we are driven to extinction, it should be by a rock named after something bad, like a Big Mac.
  
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Re:Congratulations to /. by Nutria · 2017-09-03 17:22 · Score: 1

While "550 Earth diameters" is nerdy, it's 550 Earth diameters away!!!!
Only a ninny bureaucrat with too much time on her hands would classify that as "potentially hazardous".

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"I don't know, therefore Aliens" Wafflebox1
See Florence and die by nospam007 · 2017-09-03 18:56 · Score: 1

was my first thought.
And statistics... by jandersen · 2017-09-03 20:11 · Score: 4, Informative

The asteroid is named in honor of Florence Nightingale (1820-1910), who pioneered modern nursing
Indeed, Nightingale is described as "a true pioneer in the graphical representation of statistics", and is credited with developing a form of the pie chart now known as the polar area diagram,[53] or occasionally the Nightingale rose diagram...
1. Re:And statistics... by K.+S.+Kyosuke · 2017-09-04 01:29 · Score: 1
  
  Presumably, science and math is how you pioneer *modern* anything, nursing certainly not excluded?
  
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  Ezekiel 23:20
2. Re:And statistics... by jandersen · 2017-09-04 19:45 · Score: 1
  
  Indeed. For some reason, part of my comment went missing - I quoted a bit from the previous post, then added my comment (which disappeared for some reason), then quoted a bit from wikipedia, which now shows up as the unquoted part. As for Mrs Nightingale's contributions to nursing, I think mathematics and scince were only minor contributions; far more important were things like hygiene, nutrition and simply being organised and prepared before the event, to take care of the wounded with trained nurses rather than whoever was available at the time. She didn't simply improve on nursing and care, she invented it.
7M km is "close"? by darthsilun · 2017-09-03 23:15 · Score: 1

The moon is 384K km away. This was over 20x further away.
I wish we had been warned. Then I could have spent lots of time not worrying about it in the least.
1. Re:7M km is "close"? by iggymanz · 2017-09-04 02:53 · Score: 2
  
  that made no sense whatsoever.
  How about saying it was 1/20 the average Earth / Mars distance...in other words, pretty fucking far away
2. Re:7M km is "close"? by barakn · 2017-09-04 14:52 · Score: 1
  
  Because the actual Earth-Mars distance varies so far from the average distance that the average is a useless number? Just thinking out loud here.
  
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  "I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
3. Re:7M km is "close"? by iggymanz · 2017-09-06 08:56 · Score: 1
  
  not useless at all, 46 million is the minimum, 140 million miles is the average and 401 million miles the farthest. The distance of this asteroid's closest approach being a chunk of all those distances (1/6, 1/20 and 1/50) means this asteroid was pretty fucking far away.
Re:Congratulations to /. by Hognoxious · 2017-09-04 01:06 · Score: 1

Is that centre to centre or surface to surface?

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Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Re:Congratulations to /. by K.+S.+Kyosuke · 2017-09-04 01:25 · Score: 2

You can't "trap" an object with a single body, and even with a massive second body (the Moon), it's still quite unlikely at this kind of relative velocities (how many lucky passes would you need?).

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Ezekiel 23:20
Photos ... by kbahey · 2017-09-04 03:12 · Score: 1

Here are two composite photos showing the asteroid moving against the background stars: Florence 1 and Florence 2.

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Potentially hazardous, on a future encounter by Geoffrey.landis · 2017-09-04 04:59 · Score: 1

it's 550 Earth diameters away!!!! Only a ninny bureaucrat with too much time on her hands would classify that as "potentially hazardous".
The phrase "potentially hazardous" does not mean that it will be hazardous on this particular pass. It means that it is in a orbit that makes repeated close passes near Earth, so it potentially may be hazardous on a future pass.

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1. Re:Potentially hazardous, on a future encounter by Nutria · 2017-09-04 05:16 · Score: 1
  
  the asteroid hasn't been this close to Earth since 1890, and it won't be this close again until 2500.
  How much closer will it be 483 years from now? We've got a lot more shit to worry about than this...
  
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  "I don't know, therefore Aliens" Wafflebox1
Potentially hazardous in the future. by Geoffrey.landis · 2017-09-04 05:02 · Score: 1

If this asteroid is classified as a "Potentially Hazardous Object", then why is it being reported two days *AFTER* the pass?
it is a potentially hazardous object because it is in a orbit that makes repeated close passes near Earth, and therefore it may intersect the Earth's orbit at some time in the future (beyond the time frame in which we can make exact predictions, due to chaos). It is potentially hazardous.

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What, me worry? by Geoffrey.landis · 2017-09-04 05:56 · Score: 2

The phrase "potentially hazardous" does not mean that it will be hazardous on this particular pass. It means that it is in a orbit that makes repeated close passes near Earth, so it potentially may be hazardous on a future pass.
the asteroid hasn't been this close to Earth since 1890, and it won't be this close again until 2500. How much closer will it be 483 years from now? We've got a lot more shit to worry about than this...
That's the definition of the word. The word is not defined as "objects to panic about right now."
If you don't want to worry about a potentially hazardous object, you don't have to. That does not mean it is not potentially hazardous. It just means you're not worrying about it.
More detailed definition here: https://cneos.jpl.nasa.gov/about/neo_groups.html

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1. Re:What, me worry? by Nutria · 2017-09-04 11:26 · Score: 1
  
  0.05 au sounds close, and -- astronomically -- it is. But then, Alpha Centauri is relatively close to Earth, compared to the Andromeda galaxy.
  Also, why an absolute magnitude of 22.0 or greater? What about the big, dark iron asteroid with an H of 23 who's MOID is 10^-5 au?
  
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  "I don't know, therefore Aliens" Wafflebox1
Oh, the irony (lame pun intended)! by Anonymous Coward · 2017-09-04 07:06 · Score: 1

So, a "Potentially Hazardous Object" (Wikipedia says "3122 Florence" is possibly "large enough to create serious damage were it to impact") is named "in honor of Florence Nightingale (1820-1910), who pioneered modern nursing" (from NASA statement quoted in the summary).
The idea of the asteroid version of the "Lady with the Lamp" (absolute magnitude H=22), making her rounds (every 859 days, with an eccentricity of 0.42), might one day *cause* millions of people to be killed or wounded, is simply begging the cosmos to make the irony happen.
However, I don't think this potentially embarrassing naming was intentional (e.g., dark humor inspired by knowledge of the relatively elevated risk of devastating collision). The guy who cataloged this asteroid had already cataloged many other asteroids, giving them the names of famous figures, and probably did not give the name much thought beyond the idea of "honoring" the great people of history.
https://en.wikipedia.org/wiki/Schelte_J._Bus
Measure what you can [Re:What, me worry?] by Geoffrey.landis · 2017-09-04 15:01 · Score: 1

Also, why an absolute magnitude of 22.0 or greater? What about the big, dark iron asteroid with an H of 23 who's MOID is 10^-5 au?
Because absolute magnitudes can be measured as soon as an asteroid is found, when an asteroid is far away, while what an asteroid is made of, and what its color is, cannot.

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1. Re:Measure what you can [Re:What, me worry?] by RockDoctor · 2017-09-07 20:54 · Score: 1
  
  Because absolute magnitudes can be measured as soon as an asteroid is found,
  Weeeeellll ... for certain values of "found", you could make that claim. If you've observed an object for long enough to work out it's orbit, and found a "pre-covery" image somewhere so that you've got the multiple-position data needed to calculate an orbit to MPC standards, then yes, you have the distance data needed to convert the apparent magnitude measured at your telescope into an absolute magnitude as it would have at a range of 1 AU. Of necessity, you also acquire knowledge of how far away the object is (you have calculated it's orbit). Calculating an orbit requires at least two direction measurements at different times (plus at least one distance measurement (via radar) or another direction measurement), which would rarely take less than 24 hours (two consecutive nights of observation).
  
  while what an asteroid is made of, and what its color is, cannot.
  However measuring it's colour (a hint to composition) and taking a reflection spectrum (a better hint to composition and classification) can theoretically take place in the first observation run (if your imager system can switch between imaging and spectroscopy without significant reconstruction).
  
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Re:Congratulations to /. by RockDoctor · 2017-09-07 20:22 · Score: 1

I've got a KKK tattoo. It's on the scalp that I cut from a KKK member on his way to Charlotteville. Is that OK.
The guy was alive, noisily, when I left him pegged out face down for the ants.

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Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Asteroid 3122 - from 1981 ??? by RockDoctor · 2017-09-07 21:40 · Score: 1

I thought at first - surely there were a lot more than 3121 asteroids identified by 1981, but on checking, it's MPC number (essentially the sequence number of orbits reported to the Minor Planets Centre) is 21995, so by 1981 almost 22 thousand asteroids (etc) had been identified. Which sounds much more like I thought.
For comparison, the current figures from the MPC are

Minor Planets Discovered
THIS MONTH: 21
THIS YEAR: 19154
ALL TIME: 734274
So, on a monthly basis, we're acquiring data at a rate comparable to the several hundred years of astronomy before 1981.

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Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
1. Re:Asteroid 3122 - from 1981 ??? by RockDoctor · 2017-09-07 21:42 · Score: 1
  
  Arrgh, bugger!. "on a yearly basis".
  
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  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
In theory, there's no difference between theory... by Geoffrey.landis · 2017-09-08 03:55 · Score: 1

We don't really consider an asteroid "found" until there are more two observations; otherwise you don't where it is.

However measuring it's colour (a hint to composition) and taking a reflection spectrum (a better hint to composition and classification) can theoretically take place in the first observation run (if your imager system can switch between imaging and spectroscopy without significant reconstruction).
"theoretically" maybe. Practically: no. You simply need a lot more photons to do spectroscopy than you need to just see something is there. You can only get spectra from astwroids that are reasonably bright, which, for asteroids this tiny, means reasonably close.

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http://www.geoffreylandis.com
Re:Congratulations to /. by lucm · 2017-09-08 11:12 · Score: 1

You fail at trolling but what's hilarious about this whole situation is that liberals are all getting their panties in a bunch over things that are orders of magnitude less intolerant and idiotic than what they're themselves doing.

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lucm, indeed.
Re:In theory, there's no difference between theory by RockDoctor · 2017-09-09 14:04 · Score: 1

Which is why colour estimation is easier to do than spectroscopy, though it provides less information. So your observing log looks like:
(previous observations)
Found something serendipitously in target field that's not in DSS/ 2MASS/ SIMBAD - looks like it may be an asteroid. 10 shots for positional measurement - first 3 in full bandwidth, 3 with B filter, 3 with V filter, check shot. Use exposure-doubling protocol if filtered views below detection limit.
(continue planned observing run)
[Next night] Continue programme as per booked telescope time.
Insert sequence of shots to refine positional data, or longer shots to improve SNR. Or if PI/ observatory manager thinks it's worthwhile, more time (from T.O.O. time budget?) for spectroscopy.
Return to scheduled observations.
I'm not an astronomer, but writing optimised work instructions is routine. You plan for these things, so that your technicians have a procedure for acquiring data while they're punting the question of deviating from the schedule upstairs (to you). When you're running machines with a crew of 200 and costing around $100,000/ hour you don't get to sit in the control seat again if you don't have efficient use of expensive time.

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Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"