Editing 2845: Extinction Mechanisms
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The argument is that the comet had a volume of 500 km<sup>3</sup> (10 km diameter), or 5×10<sup>14</sup> L. Earth has a surface area of around 500 million km<sup>2</sup>, or 5×10<sup>14</sup> m<sup>2</sup>. The idea is that the comet broke up into liter-sized rocks, so that there were sufficient of these to fall, on average, one on every square meter of surface. Somehow, these rocks managed to fall in a distribution such that they directly hit each of the dinosaurs, but presumably did not hit the other forms of life that did not go extinct. It is unclear how such a breakup or scattering might have occurred – a body that passes within Earth's {{w|Roche limit}} will eventually break up into a ring, but this limit is generally a single-digit multiple of the planet's radius, so an object on an inbound collision course would only experience high tidal forces for a matter of minutes before impact. | The argument is that the comet had a volume of 500 km<sup>3</sup> (10 km diameter), or 5×10<sup>14</sup> L. Earth has a surface area of around 500 million km<sup>2</sup>, or 5×10<sup>14</sup> m<sup>2</sup>. The idea is that the comet broke up into liter-sized rocks, so that there were sufficient of these to fall, on average, one on every square meter of surface. Somehow, these rocks managed to fall in a distribution such that they directly hit each of the dinosaurs, but presumably did not hit the other forms of life that did not go extinct. It is unclear how such a breakup or scattering might have occurred – a body that passes within Earth's {{w|Roche limit}} will eventually break up into a ring, but this limit is generally a single-digit multiple of the planet's radius, so an object on an inbound collision course would only experience high tidal forces for a matter of minutes before impact. | ||
| − | The title text refers to a hypothetical event early in Earth's history, ironically known as the {{w|Late Heavy Bombardment}}, in which a number of asteroids struck the Earth and other terrestrial planets around 4 billion years ago. The mass extinction event of 66 million years ago is then referred to as the "Comparatively Light but Oddly Specific Bombardment", presumably because it isn't as heavy as the LHB, but oddly specific in its targets. | + | The title text refers to a hypothetical event early in Earth's history, ironically known as the {{w|Late Heavy Bombardment|Late Heavy Bombardment}}, in which a number of asteroids struck the Earth and other terrestrial planets around 4 billion years ago. The mass extinction event of 66 million years ago is then referred to as the "Comparatively Light but Oddly Specific Bombardment", presumably because it isn't as heavy as the LHB, but oddly specific in its targets. |
==Transcript== | ==Transcript== | ||
