Crater & cat
Further to the Astral Bulletin [FT385:8-9], there is an article by Jonathan Mayo in Mail Online (5 October), giving a theoretical timeline for the Chicxulub impact, which it is widely believed caused the mass dinosaur extinction. Quoting a study from the University of Texas, he states that one day after impact “Debris from the crater is still heading into space at high speed. Within weeks, some of it will be orbiting the Sun. Fragments will eventually land on Mars and on the moons of Saturn and Jupiter. This debris may contain living microbes and so have exported life from Earth into space.” That could complicate the search for truly alien life on celestial bodies.
• Regarding the origin of the phrase “to grin like a Cheshire Cat” [FT387:58-59], Rob Gandy’s cheese theory sounds the most likely to me. You have the image of a grinning cat, and it originates in Cheshire. Simples! (Now, don’t get me started on the fact that meerkats are from
Africa, not Russia.)
• I enjoyed Mark Greener’s review of Astrobiology by Andrew May[ FT387:61]. He makes some good points. However, I think that the evolutionary convergence theory he mentions has some weaknesses in this context. It seems to me that it is only by chance that the human race came to be. Mass extinctions have occurred in the past, one of which eradicated the vast majority of dinosaurs, and it was this that is believed to have brought mammals to prominence. In addition, according to genetic studies, the human population may have dropped to as low as 2,000, about 70,000 years ago.
Similar events may have happened on other planets, so who can say what intelligent
life may have evolved there? Nature is a remarkable thing, as amply illustrated on our own planet. I think it would be somewhat unimaginative to assume that planets with similar environments to Earth would have human-like intelligent life. There’s more than one way to skin a (Cheshire) cat. The aliens in Star Trek are usually humanlike, for obvious reasons, but that is not real life, although I must admit I avoid wearing red shirts, just in case!
Dave Miles
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