The Chicxulub meteor hit the earth at a 27-degree angle …
… coming out of the southeast (and going northwest, obviously) …
… at about 45,000 mph.
That got me to wondering: If we were there to see it coming, how long would have been streaking across the sky? I’m thinking it was going that fast we would have had only a one- or two-second warning.
In the movies, meteors hitting the earth always give us a good long look before all the destruction.
The atmosphere gets pretty darn thin above 10 miles or so, but let’s be generous and say the meteor will make a trail starting at 20 miles up (that’s probably a bit too generous). At an angle of 27 degrees, the meteor is going to go through roughly 44 miles of atmosphere before hitting the Earth.
At 45,000 miles per hour, that works out to about 3 1/2 seconds.
I did some googling and my estimation was way off. According to The Google, meteors start to burn up around 60 miles up, not 20. So multiply everything by 3 and you end up with about 10 1/2 seconds.
The above discusses the asteroid’s trail through the atmosphere, which, if there has been any humans around at the time, would have been the first obvious sign that something very unusual was happening. But if those humans had been knowledgeable astronomers with star maps, according to a recent article on the subject the asteroid would have been visible to the naked eye about 60 hours prior to impact, appearing as a star where no star should have been. It would then have been seen to be slowly and then more rapidly brightening over the course of those two and a half fateful days, until it finally hit the atmosphere and flashed into brilliant light. The article (The Day the Dinosaurs Died, by Douglas Preston, in the New Yorker) describes what models tell us likely happened next:
Within two minutes of slamming into Earth, the asteroid, which was at least six miles wide, had gouged a crater about eighteen miles deep and lofted twenty-five trillion metric tons of debris into the atmosphere … When Earth’s crust rebounded, a peak higher than Mt. Everest briefly rose up. The energy released was more than that of a billion Hiroshima bombs … Much of the [ejected] material was several times hotter than the surface of the sun, and it set fire to everything within a thousand miles … countless red-hot blobs of glass called tektites … blanketed the Western Hemisphere …
The article goes on to say that some of the ejecta escaped the earth’s gravity and went into orbit around the sun, some of it eventually strewn on other planets and moons in the solar system, particularly Mars. Tens of thousands of pounds of debris may have landed on Titan, Europa, and Callisto, where it’s remotely possible that still-living microbes may have spawned the beginning of life there.
To somewhat expound on the above answer, Wikipedia gives the pronunciation as /ˈtʃiːkʃʊluːb/ in English, which would most closely correspond to CHEEK-shuh-lube" with the “shuh” containing the same vowel as “put” in most American accents. Back in the day, we’d write it out something like CHEEK-sho͝o-lube phoenetically.
The Mayan pronunciation is listed as /tʃʼikʃuluɓ/, which is slightly different (the “i” and “u” vowels are shorter, and bother "u"s are pronounced with an “oo” [as in “boo” or “moo”]rather than “o͝o” [and in “cook” or “book” or “put”] sound.) Of course, your dialect pronunciations may vary, so if my plain English examples don’t work in your dialect, that’s why it’s nice to have some familiarity with IPA.
At any rate, when you see an “x” in a Mayan or Nahuatl word, it usually represents the “sh” sound (at least as far as I’ve always seen, like in Uxmal, or the salsa xni-pec; I think in some Nahutl words it sounds closer to “ch” when used as an initial consonant, but it’s hard for me to tell.)
That has always vexed me as well, even documentaries that claim to be accurate depict it that way. It is simply wrong, as has been well calculated by engineer_comp_geek on his second try. A ten km asteroid hits the ground while the upper part is just inside the atmosphere and it is so fast you don’t want to be near the event without sunglasses. Nice to know somebody else is also troubled by this ubiquitous inaccuracy.
