6 ms·

A large asteroid recently flew close to Earth

32 points by herve76 10y ago

life2hack 10y ago
Well, it was small, but should have been spotted.
- mitchty 10y ago
  Spotted by what or who exactly? If we want to see asteroids we need satellites in orbit around the sun monitoring our blind spots (things coming at us from the sun). Until then we'll never be able to spot things in all circumstances. It also was spotted: A smallish asteroid zoomed past Earth this morning (Jan. 9), just two days after scientists first spotted the space rock. Even assuming we had perfect alerting and this was a problem, what action should have been taken considering this is a common occurrence?
  - jessriedel 10y ago
    Asteroids are identified and tracked with radio waves, not visible light, so I don't think sun glare is a major issue.
    - sxcurry 10y ago
      I've never heard this before. Can you provide a reference for more info?
      - jessriedel 10y ago
        Radar is how lots of asteroid imaging is done: https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_comets https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_... However, I wasn't aware of the optical methods mitchty was referring to.
    - LeoPanthera 10y ago
      This is not correct. Optical telescopes are used, in conjunction with the WISE space telescope. https://www.nasa.gov/content/asteroid-grand-challenge/detect/how-do-we-detect-asteroids https://www.nasa.gov/content/asteroid-grand-challenge/detect...
    - CydeWeys 10y ago
      Active radar is subject to n^4 (!!!) drop-off with distance and as such is not useful for astronomical observation of any sort. Only passive detection is useful, which has a much more manageable dropoff of n^2. And asteroids don't emit radio waves, but they do reflect the Sun's light.
      - snrplfth 10y ago
        I think they're talking about the Goldstone Array: https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar It's used for high-res imaging of asteroids that pass close by.
        CydeWeys 10y ago
        Interesting, though it appears to be useful for imaging, not so much detection.
    - mitchty 10y ago
      Radio only works for relatively close asteroids. https://en.wikipedia.org/wiki/Sentinel_Space_Telescope https://en.wikipedia.org/wiki/Sentinel_Space_Telescope Which was sadly cancelled: http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-pulls-plug-killer-asteroid-hunter-Sentinel-mission-set-search-dangerous-space-rocks-loses-30-million-support.html http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-... But the principle was based off infrared: http://aviationweek.com/space/ball-aerospace-ramps-sentinel-asteroid-mission http://aviationweek.com/space/ball-aerospace-ramps-sentinel-... The canadian satellite also uses light: https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance_Satellite https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance... Visible light is only one fraction of the spectrum, infrared is far more valuable for detection. Most asteroids are detected via passive observation. Radio waves are not conducive to detecting asteroids.
      - jessriedel 10y ago
        My mistake. Thank you for the correction.
toodlebunions 10y ago
A regular occurrence
jessaustin 10y ago
In case one prefers not to get astronomical news from "Business Insider": http://www.space.com/35265-newfound-asteroid-buzzes-earth-2017-ag13.html http://www.space.com/35265-newfound-asteroid-buzzes-earth-20...
- david-given 10y ago
  Autoplay video (with sound).
  - jessaustin 10y ago
    Huh. It didn't autoplay for me, but I agree that's quite annoying.
  - flukus 10y ago
    Also request ability to show notifications.
  - DrScump 10y ago
    ...if you have Flash enabled. The video adds nothing, BTW.
jessriedel 10y ago
FYI, my understanding is that all the asteroids capable of posing an existential threat to humanity are known and tracked. Smaller asteroids like this one are not, but there is an upper bound on the possible damage they can do, and the damage is pretty small in expectation (i.e., when weighted by the chance of a collision). On the other hand, it's still possible that a long-period comet or rogue planet could come out of nowhere and wipe humanity out. Presumably the odds are extremely remote, judging by the rarity of extinction-level events in the geological record.
- cjensen 10y ago
  Goodness no! An asteroid in an elliptical orbit, for example, could be a civilization killer and might currently be undetectably far away right now. We are missing a lot right now, and we need to spend money on much better surveys.
  - jessriedel 10y ago
    You are at best disputing my terminology. An object on such a highly eccentric orbit would be classified as a long-period comet, which I mentioned. Yes, you can argue semantics about whether we might still call such an object an "asteroid" if it had a certain composition or primordial origin (which would be extremely unlikely for such an orbit). But there is no sharp division between asteroid and comment composition (it's a bimodal but smooth continuum) and this isn't relevant for the purposes of tracking such objects.
    - credit_guy 10y ago
      There are two families of asteroids in the asteroid belt, Alinda and Griqua, which have quite eccentric orbits, and their orbits become more and more eccentric as time passes. From time to time they come close to Mars (or other interior planet), which slings them in a random direction. Some may end up hitting us. That's how the Kirkwood gaps in the asteroid belt are formed. https://en.m.wikipedia.org/wiki/Kirkwood_gap https://en.m.wikipedia.org/wiki/Kirkwood_gap
halspero 10y ago
There are whoppers out there capable of resetting civilisation. Do we have to have a small city destroyed before we design and build the technology to avert all future impacts?
- astrodust 10y ago
  What technology could avert this sort of disaster? The USA is apparently retiring from the business of all things progressive and space-oriented, so someone else will have to take up the torch. Right now it looks like the only country with the resources and willpower is China. I hope some states like California can pitch in and save NASA by funding it directly before it's thrown in the garbage.
  - gooseus 10y ago
    I agree, though the fact still remains that most funding will go to novel (and yes, important) scientific research rather than civilization-saving (and way more important) asteroid defense. On the importance... if human civilization discovers the precise nature of the cosmos and no one is around in 100 years capable of learning about it, does it matter? Given the current political and social climate I think it's a lot more pragmatic to learn how to organize and preserve our knowledge such that it's as easily decoded and readily available as possible on as large a timescale as we can manage.
    - dTal 10y ago
      I'll quote one of the most insightful comments I've read on HN: "Most of our physical tech stack is read-only executable code: there isn't a civilizational "source code" that shows from first principles how to build up to our current technology layer. For that matter, not even from first principles to turn of the 20th century technology level." (https://news.ycombinator.com/item?id=12824828 https://news.ycombinator.com/item?id=12824828)
      - halspero 10y ago
        Here is James Burke on this topic: https://www.youtube.com/watch?v=PeROEoimj7I https://www.youtube.com/watch?v=PeROEoimj7I And here's Primitive Technology man: https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA (Should we leave his videos lying around on clockwork tablets?)
aggie 10y ago
My favorite proposed method of asteroid deflection: http://www.planetary.org/explore/projects/laser-bees/ http://www.planetary.org/explore/projects/laser-bees/ The idea is to ablate material off of one side of the asteroid using lasers and/or mirroring sunlight to redirect its trajectory. This is better than using a nuclear bomb which risks fragmenting the asteroid. If you intercept early enough it doesn't take much of a change in trajectory to miss Earth.

32 points by herve76 10y ago

life2hack 10y ago

Well, it was small, but should have been spotted.

mitchty 10y ago
Spotted by what or who exactly? If we want to see asteroids we need satellites in orbit around the sun monitoring our blind spots (things coming at us from the sun). Until then we'll never be able to spot things in all circumstances. It also was spotted: A smallish asteroid zoomed past Earth this morning (Jan. 9), just two days after scientists first spotted the space rock. Even assuming we had perfect alerting and this was a problem, what action should have been taken considering this is a common occurrence?
- jessriedel 10y ago
  Asteroids are identified and tracked with radio waves, not visible light, so I don't think sun glare is a major issue.
  - sxcurry 10y ago
    I've never heard this before. Can you provide a reference for more info?
    - jessriedel 10y ago
      Radar is how lots of asteroid imaging is done: https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_comets https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_... However, I wasn't aware of the optical methods mitchty was referring to.
  - LeoPanthera 10y ago
    This is not correct. Optical telescopes are used, in conjunction with the WISE space telescope. https://www.nasa.gov/content/asteroid-grand-challenge/detect/how-do-we-detect-asteroids https://www.nasa.gov/content/asteroid-grand-challenge/detect...
  - CydeWeys 10y ago
    Active radar is subject to n^4 (!!!) drop-off with distance and as such is not useful for astronomical observation of any sort. Only passive detection is useful, which has a much more manageable dropoff of n^2. And asteroids don't emit radio waves, but they do reflect the Sun's light.
    - snrplfth 10y ago
      I think they're talking about the Goldstone Array: https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar It's used for high-res imaging of asteroids that pass close by.
      - CydeWeys 10y ago
        Interesting, though it appears to be useful for imaging, not so much detection.
  - mitchty 10y ago
    Radio only works for relatively close asteroids. https://en.wikipedia.org/wiki/Sentinel_Space_Telescope https://en.wikipedia.org/wiki/Sentinel_Space_Telescope Which was sadly cancelled: http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-pulls-plug-killer-asteroid-hunter-Sentinel-mission-set-search-dangerous-space-rocks-loses-30-million-support.html http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-... But the principle was based off infrared: http://aviationweek.com/space/ball-aerospace-ramps-sentinel-asteroid-mission http://aviationweek.com/space/ball-aerospace-ramps-sentinel-... The canadian satellite also uses light: https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance_Satellite https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance... Visible light is only one fraction of the spectrum, infrared is far more valuable for detection. Most asteroids are detected via passive observation. Radio waves are not conducive to detecting asteroids.
    - jessriedel 10y ago
      My mistake. Thank you for the correction.

toodlebunions 10y ago

A regular occurrence

jessaustin 10y ago

In case one prefers not to get astronomical news from "Business Insider": http://www.space.com/35265-newfound-asteroid-buzzes-earth-2017-ag13.html http://www.space.com/35265-newfound-asteroid-buzzes-earth-20...

david-given 10y ago
Autoplay video (with sound).
- jessaustin 10y ago
  Huh. It didn't autoplay for me, but I agree that's quite annoying.
- flukus 10y ago
  Also request ability to show notifications.
- DrScump 10y ago
  ...if you have Flash enabled. The video adds nothing, BTW.

jessriedel 10y ago

FYI, my understanding is that all the asteroids capable of posing an existential threat to humanity are known and tracked. Smaller asteroids like this one are not, but there is an upper bound on the possible damage they can do, and the damage is pretty small in expectation (i.e., when weighted by the chance of a collision). On the other hand, it's still possible that a long-period comet or rogue planet could come out of nowhere and wipe humanity out. Presumably the odds are extremely remote, judging by the rarity of extinction-level events in the geological record.

cjensen 10y ago
Goodness no! An asteroid in an elliptical orbit, for example, could be a civilization killer and might currently be undetectably far away right now. We are missing a lot right now, and we need to spend money on much better surveys.
- jessriedel 10y ago
  You are at best disputing my terminology. An object on such a highly eccentric orbit would be classified as a long-period comet, which I mentioned. Yes, you can argue semantics about whether we might still call such an object an "asteroid" if it had a certain composition or primordial origin (which would be extremely unlikely for such an orbit). But there is no sharp division between asteroid and comment composition (it's a bimodal but smooth continuum) and this isn't relevant for the purposes of tracking such objects.
  - credit_guy 10y ago
    There are two families of asteroids in the asteroid belt, Alinda and Griqua, which have quite eccentric orbits, and their orbits become more and more eccentric as time passes. From time to time they come close to Mars (or other interior planet), which slings them in a random direction. Some may end up hitting us. That's how the Kirkwood gaps in the asteroid belt are formed. https://en.m.wikipedia.org/wiki/Kirkwood_gap https://en.m.wikipedia.org/wiki/Kirkwood_gap

halspero 10y ago

There are whoppers out there capable of resetting civilisation. Do we have to have a small city destroyed before we design and build the technology to avert all future impacts?

astrodust 10y ago
What technology could avert this sort of disaster? The USA is apparently retiring from the business of all things progressive and space-oriented, so someone else will have to take up the torch. Right now it looks like the only country with the resources and willpower is China. I hope some states like California can pitch in and save NASA by funding it directly before it's thrown in the garbage.
- gooseus 10y ago
  I agree, though the fact still remains that most funding will go to novel (and yes, important) scientific research rather than civilization-saving (and way more important) asteroid defense. On the importance... if human civilization discovers the precise nature of the cosmos and no one is around in 100 years capable of learning about it, does it matter? Given the current political and social climate I think it's a lot more pragmatic to learn how to organize and preserve our knowledge such that it's as easily decoded and readily available as possible on as large a timescale as we can manage.
  - dTal 10y ago
    I'll quote one of the most insightful comments I've read on HN: "Most of our physical tech stack is read-only executable code: there isn't a civilizational "source code" that shows from first principles how to build up to our current technology layer. For that matter, not even from first principles to turn of the 20th century technology level." (https://news.ycombinator.com/item?id=12824828 https://news.ycombinator.com/item?id=12824828)
    - halspero 10y ago
      Here is James Burke on this topic: https://www.youtube.com/watch?v=PeROEoimj7I https://www.youtube.com/watch?v=PeROEoimj7I And here's Primitive Technology man: https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA (Should we leave his videos lying around on clockwork tablets?)

aggie 10y ago

My favorite proposed method of asteroid deflection: http://www.planetary.org/explore/projects/laser-bees/ http://www.planetary.org/explore/projects/laser-bees/ The idea is to ablate material off of one side of the asteroid using lasers and/or mirroring sunlight to redirect its trajectory. This is better than using a nuclear bomb which risks fragmenting the asteroid. If you intercept early enough it doesn't take much of a change in trajectory to miss Earth.