Planetary scientists have long believed that Earth formed from planetary objects similar to meteorites. Then, a decade ago, perplexing new measurements challenged that assumption by showing that Earth and its supposed “building blocks” actually contain significantly different isotopic compositions.
“These recent measurements contribute to the growing evidence that the meteorites delivered to Earth provide an imperfect match to Earth’s composition,” said Richard Carlson, director of the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Carlson was one of the scientists who found the compositional mismatch between meteorites and Earth 10 years ago. “This realization opens new views both to how Earth formed and to the bulk chemical composition of our home planet.” Paper. (paywall) – C. Burkhardt, L. E. Borg, G. A. Brennecka, Q. R. Shollenberger, N. Dauphas, T. Kleine. A nucleosynthetic origin for the Earth’s anomalous 142Nd composition. Nature, 2016; 537 (7620): 394 DOI: 10.1038/nature18956More.
Odd, considering that the solar system appears fine-tuned:
The more we learn, the more its features appear fine-tuned to enable the eventual existence of advanced life on Earth. A recent study, for example, shows a residual population of planetesimals (small, primordial solar system bodies, in this case measuring no larger than 20 meters across) with a total mass just-right for life’s sake. This total mass played an essential role in dampening the eccentricities and inclinations of Venus, Earth, and Mars from their initially high values to their current near zero values, as well as in sufficiently enriching Earth’s crust with siderophile (iron/arsenic/sulfur-loving) elements so that advanced life eventually would be possible on Earth. (Hugh Ross, 2012)
It could be a design feature.
But no, there is an infinity of solar systems out there in the multiverse, right, so no surprise ours look fine-tuned. After all, we wouldn’t be here otherwise, and anyway, there is always: A cognitive scientist’s “evolutionary argument against reality”
See also: Copernicus, you are not going to believe who is using your name. Or how.
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