One fine day a Norse god, Loki assembled an asteriod resembled Chicxulub impactor using numerous Lego® bricks(the same one we have on Earth) in Jupiter's orbit. He wanted to duplicate the event that triggered the extinction of the dinosaurs so he hurl the Lego asteriod towards Earth at approximately 20Km/s and do not worry I am not asking how many bricks is needed to assemble such an asteroid. Using the same parameters as the Chicxulub impactor except it is assembled with plastic Lego® bricks instead, how can we prevent a catastrophic calamity?

P.S Loki maybe mean but he will not try to intervene with our defenses and we have been keeping a close watch at Loki while he is busy playing with the Lego® bricks. Also please do not tell me this asteriod will disintegrate enroute to Earth, in that case kindly provide guidance to Loki so that he can become master builder in exchange for your own safety. (Loki will applaud answer that contains mathematic and advise whether does he really need superglue not to be mistaken with "Kragle".)


  • Size: 12000m (diameter)
  • Velocity: 20000m/s
  • Location of impact: Chicxulub
  • Impact angle: 90°

Comment below if you have doubt.

  • $\begingroup$ Same as the other asteroid questions, but the huge size is offset by the low density. So more like the mass of a typical asteroid. You don't need us to calculate the mass for you. $\endgroup$
    – JDługosz
    Aug 19 '15 at 6:07
  • $\begingroup$ For the masper builder subquestion: LEGO(R) bricks are made from ABS plastic, which is soluble in acetone. If he used a bit of acetone vapor while assempling his asteroid, the bricks would fuse together. That should prevent your LEGO(R) Asteroid from breaking apart en route. It woudl eb a shame, too, but i doubt Loki had intended to re-use them anyway. $\endgroup$
    – Burki
    Aug 19 '15 at 7:02
  • $\begingroup$ @Burki noted and I sincerely doubt Loki would need another attempt. $\endgroup$
    – user6760
    Aug 19 '15 at 7:13
  • $\begingroup$ I don't understand the question. Why do you insist that the asteroid be made of Lego bricks when you pre-define the important parameters, which are not at all consistent with Lego bricks? $\endgroup$
    – Hackworth
    Aug 19 '15 at 7:58
  • $\begingroup$ @Hackworth oops my mistake I got carried away while running through some figures I've edited the question. $\endgroup$
    – user6760
    Aug 19 '15 at 8:05

Assuming the C. impactor had a density of solid rock (think granite), it had a density of about 2500 kg/m³.

A 2x4 Lego brick has a weight of 2.5 grams and a volume (including the empty space between struts) of 4823 mm³, which gives a Lego structure a density of ca. 518 kg/m³ when assembled, so the L. impactor had about a fifth of the density of the C. impactor.

Therefore, if the L. impactor had the same speed as the C. impactor, it would have about 20% of the total kinetic energy. However, in the grand scheme of things, that is not a significant difference.

Using all the provided paramters and putting them into the Earth Impact Effects Program, we see that the C. impactor and the L. impactor leave quite similar-sized craters. Only the amount of ejected material is about proportional to their kinetic energy.

All in all, the L. impactor looks a lot like another extinction-level event. Because of their kinetic energies, while differing by a factor of 5, with current technology we have about the same options for defending against the L. impactor as we would have against the C. impactor: None.


Not the answer you're looking for? Browse other questions tagged .