3 ms·
Ancient crystals might rewrite Earth's early history
- clavalle 11y agoThat's good news for those of us that hope we find life outside of Earth. Inhospitable, once again, is shown not to mean lifeless.
- ajuc 11y agoAnd bad news for those terrified by Drake's equation.
- guelo 11y agoI'm really confused why a fleck of crystalline carbon is considered a bio marker.
- rubidium 11y agoFrom my read, its the ratio of carbon 12 to 13.
- mkaziz 11y agoI hate headlines with "might" in it. Let me know when you figure it out - otherwise you're just littering my brain.
- Sharlin 11y agoI'm afraid I have some bad news for you about how science works.
- dekhn 11y agoThe actual paper is also fairly cautious. This is some pretty tricky stuff at the edge of what is technically capable to conclude. They're basically sharing their findings with the community to get feedback and criticism- and if they survive the criticismthe terminology will get a bit stronger.
- rubidium 11y agoPNAS Paper Abstract: Evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ∼3.5 billion years (Ga), the chemofossil record arguably to ∼3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ^13 C_PDB of −24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ∼300 My earlier than has been previously proposed.
- dang 11y agohttps://news.ycombinator.com/item?id=10415212 https://news.ycombinator.com/item?id=10415212