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Space Earth

What If You Could See Asteroids In the Night Sky? 54

Posted by timothy from the hard-rain dept.
An anonymous reader writes: As part of Asteroid Day a 360-degree video rendering the night sky with the population of near-earth asteroids included has been created by 'Astronogamer' Scott Manley. The video shows how the Earth flies through a cloud of asteroids on its journey around the sun, and yet we've only discovered about 1% of the near earth asteroid population.
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What If You Could See Asteroids In the Night Sky? More

What If You Could See Asteroids In the Night Sky?

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  • Out of sight, out of mind seems to be the current mindset. We'll probably be wiped out by one at some point.

    • Re:We'd probably be more on protecting ourselves. (Score:4, Funny)

      by ArcadeMan ( 2766669 ) on Tuesday June 30, 2015 @12:41PM (#50019953)

      Yeah, right. I'm pretty sure that's not going to happen any time so{#`%${%&`+'${`%&NO CARRIER

    • I've near cities all my life. So everything in the sky is pretty much "out of sight, out of mind" to me. I didn't know what the Milky Way was until I saw a picture of it in a book.

  • How do we know we've only discovered 1% of NEAs? (Score:5, Interesting)

    by sjbe ( 173966 ) on Tuesday June 30, 2015 @12:34PM (#50019893)

    The video shows how the Earth flies through a cloud of asteroids on its journey around the sun, and yet we've only discovered about 1% of the near earth asteroid population.

    Ok, how do we know what we haven't discovered yet? I know statistical techniques for estimating population sizes of wildlife. (Catch some number, tag and release, catch a bunch more and see how many tagged ones you catch which gives you a population estimate) I'm not sure those techniques are applicable here. Anybody have any idea how this estimate was arrived at or is it taken straight out of someone's derriere? Measurements of orbit perturbations? Something else?

    • I was kind of surprised by that factoid. Especially since the WISE [wikipedia.org] data hasn't been completely released yet.

    • It's not that hard, you know how much of the sky you've looked at. You know the sizes, positions, and velocities of all the asteroids you've cataloged. From there it's a non-trivial but certainly doable calculation to come up with an estimate of the total number.

      • It's not that hard, you know how much of the sky you've looked at. You know the sizes, positions, and velocities of all the asteroids you've cataloged. From there it's a non-trivial but certainly doable calculation to come up with an estimate of the total number.

        That only works if you have some way to make reasonable assumptions or statistical inferences about what is in the bits of the sky you haven't looked. It's not clear to me if such assumptions are appropriate here since we've routinely been surprised by what we find in bits of the sky where we haven't looked carefully. Plus isn't part of the problem just that asteroids can be really hard to see even when we are looking right at them?

      • And you assume that you found ALL the asteroids in the sky you've looked at.

        Also, asteroids that moved into your field of study.

    • Re:How do we know we've only discovered 1% of NEAs (Score:5, Insightful)

      by aaron4801 ( 3007881 ) on Tuesday June 30, 2015 @12:46PM (#50019999)
      If it's just a count of objects, "1%" doesn't mean much anyway. We should be much more interested in mapping Mass. A 1kg asteroid is mostly harmless (to Earth, though it could be catastrophic for man-made satellites). This may be a faulty assumption, but I would think the larger, more dangerous objects would be detected first. If so, 1% of the total number may represent something like 50% of the total mass of all NEAs. If that's true, it's far less ominous than saying "99% of potential Earth-impacting asteroids are currently hidden!!!1!"
      • About haft the mass of the asteroid belt is in the 4 largest bodies. Also note that is half of the *estimated total mass*. We have very accurate orbital models and combined with what we have seen we can get fairly accurate estimates. It is very unlikely to get a big surprise. Because as you say, it would be easy to detect it.

    • Re:How do we know we've only discovered 1% of NEAs (Score:4, Informative)

      by rubycodez ( 864176 ) on Tuesday June 30, 2015 @12:48PM (#50020007)

      data from impact areas on moon, discovery rate, increase in counts with improvement in instruments are some factors:

      http://www.lsst.org/lsst/publi... [lsst.org]

    • Re: (Score:3)

      by khallow ( 566160 )
      The distribution of asteroids that we can detect follow a power law: for a given cross-sectional area, the number is crudely inversely proportional. This not only holds for the biggest ones which we can observe in telescopes, but also meteorite impacts with the Earth and Moon. So we have estimates of asteroid populations by size from the largest to well below the minimum size which can cause harm to us on Earth.

    • If I were doing this, I'd have a probe go through the asteroid belt and catalogue the number of asteroids it identifies. Then I'd compare that to the number I'd catalogued previously. That misses rogue asteroids, of course, and assumes that asteroid distribution is uniform throughout the belt.

  • If we can see an asteroid with the naked eye it might be time to duck.
    Its almost certainly too late to call B ruce Willis

  • that means the Vorlons are using mass drivers to attack your home world.

    • Re: (Score:1)

      by Anonymous Coward

      that means the Vorlons are using mass drivers to attack your home world.

      I'm pretty sure that was the Centauri. Vorlons developed a sudden habit of blowing up planets instead.

  • while video is great it is biased (Score:3, Informative)

    by Sergey Kurdakov ( 3652003 ) on Tuesday June 30, 2015 @12:58PM (#50020099)

    First, Scott does not mention, that most dangerous asteroids are found

    >95% of 1 km size asteroids
    >90% for 500 m size asteroids
    ~60-70% 300 m size asteroids

    so yes, we know 1% of asteroids, but still - the danger now for a person to be killed by asteroid is more than 100 times less, than it was two decades ago

    another problem with his video, that he omits to mention, that inner asteroids are either harmless, or if they intersect earth orbit - they could be tracked at dusk/dawn ( just like venus is visible - and venus is quite far from being able to hit earth, so closer asteroids and relatively big asteroids are easier to find )

    then about finding inner asteroids with space crafts - it is not just B612 foundation, which deals with that , but there are other proposals

    http://arxiv.org/abs/1503.0794... [arxiv.org] - which is really cheap ( though idea requires some more development )
    or http://xxx.lanl.gov/abs/1501.0... [lanl.gov] neocam - the paper has a proof that it is somewhat more realistic than B612 proposal and is not less efficient.

    • ...so yes, we know 1% of asteroids, but still - the danger now for a person to be killed by asteroid is more than 100 times less, than it was two decades ago

      Actually, the danger to a person being killed by an asteroid is not changed. That won't happen until some technology is developed to deal with them. But, at least we would know the end is coming.

      • >Actually, the danger to a person being killed by an asteroid is not changed.

        it changed - there are statistically only 6 asteroids out ~30 000 most big which could hit earth and do intersect earth orbit ( others just fly near - but not about to hit ).

        Now we know that 95% 1km won't hit, this the probability that there are no dangerous 1 km asteroid now in collision course - is much higher. Then iff we know orbits of 100% of all 1 km asteroids - even if we don't have means to deflect them, but know that

        • Re:while video is great it is biased (Score:4, Insightful)

          by Dcnjoe60 ( 682885 ) on Tuesday June 30, 2015 @03:06PM (#50021253)

          Whether we knew/know about an asteroid strike doesn't change whether the strike will occur. As such, the actual likelihood of an asteroid hit is the same, either way. What has changed is our knowledge that it is going to occur.

          Put differently, there are a finite number of asteroids in the solar system. If one othem is on a trajectory that will eventually impact the earth, the likelihood of an earth impact is unchanged whether we know it or not. Likewise, if none of them are on a trajectory to impact earth, the likelihood of an earth impact is unchanged whether we know it or not.

          At this point in time, there are only two options - either the earth will be hit or it will never be hit. The more we know about the asteroids and their trajectories does not change those results (unless by knowing, we have a means to divert the collision, which currently, we can't).

      • Actually, the danger to a person being killed by an asteroid is not changed. That won't happen until some technology is developed to deal with them. But, at least we would know the end is coming.

        The danger of a given person getting killed has not changed, but the chance of a person getting killed may have increased slightly with the increase in human population.

    • Re: (Score:1)

      by Anonymous Coward

      That is because Scott Manley is only a self-proclaimed astronomer. He has no degrees or credentials of any kind to support that claim.

      • No, he has a degree ( as he somewhere explained ), but rather likes b612 as a private company ( he is himself is not from government)

        • Re: (Score:1)

          by Anonymous Coward

          He doesn't have a degree in astronomy though. Otherwise he wouldn't be working as a web developer and additionally claiming to be a "Hacker, DJ, Astronomer, Dad, Scotsman, Capsuleer".

          Sorry, but I don't trust a thing this guy says. He's not legit.

          • Which is why you posted this pearl of wisdom as an AC.
          • However i am. And he has done a good job. the data is public. You can replicated the results.

  • Answer: (Score:3)

    by avandesande ( 143899 ) on Tuesday June 30, 2015 @01:13PM (#50020195) Journal

    You Could See Asteroids In the Night Sky...

  • What would I do if I could see an asteroid? Shit my pants, of course.

  • I'm still not sure how In intend to celebrate the IMPENDING DISMAL FAILURE of the EADP Mission fund raiser [indiegogo.com] to raise $200k for producing a set of plans to for a viable asteroid deflection/destruction mission. Win or lose, something besides NOTHING ready to deploy on short notice. What kind of cake would be appropriate for this level of fail?

    185 people have contributed $8,803 of $200k. Two of them are me.

    WHAT IF a simple test appeared out of the blue one day... something that you could not ignore. Despite any

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