Early Earth was a molten, asteroid-blasted hellscape. Scientists now know when that changed: « A new study narrows the timeline for the emergence of life on Earth. »
https://gizmodo.com/early-earth-was-a-molten-asteroid-blasted-hellscape-scientists-now-know-when-that-changed-2000815377
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« We used a different approach than previous studies, which were based on geochemical modeling, biomolecular analyses, and models of early atmospheric chemistry. We examined both detrimental effects of impacts, such as temperature-induced degradation of key biomolecules, and effects conducive to life, such as generation of hydrothermal systems. »
Reference: Abramov, O., Medvegy, A., Kremer, B. *et al.* A Hadean timeline for the emergence of the RNA World. *Nat Commun* **17**, 9790 (2026). https://doi.org/10.1038/s41467-026-76978-3
The chicken and egg problem is probably not a good opening line since it’s an unscientific false dilemma.
[From the paper](https://www.nature.com/articles/s41467-026-76978-3)
> The model’s predictions, even when considering an unrealistically high delivered mass scenario, consistently yield zircon ages expected from the crystallization of impact melts that are significantly older than those observed empirically from the detrital Hadean zircon record. This discrepancy implies that other geological processes besides impacts were more important to crust formation or destruction.
This is likely due to volcanism or early plate tectonics. Giant volcanic eruptions and rifting would have warmed the Earth even more than presented in the paper. But since the model excludes the main process recycling the crust, I have to wonder how applicable it is. The estimates for habitability may be more applicable to Mars than to the Earth.