Extended Data Fig. 1: Impactor size-frequency distributions.
From: Delayed and variable late Archaean atmospheric oxidation due to high collision rates on Earth
Gray curve is the MBA SFD from ref. 40. This SFD was able to generate a NEO SFD in agreement with observations at that time. The orange curve is an update of the MBA SFD—our nominal MBA SFD—that better fit the current NEO SFD (green). The vertical dashed lines indicate reference sizes of 33 m and 5 km (see text for details). For completeness, 1.1 km is also indicated, corresponding to an impactor size that would make a 20 km lunar crater (often used for calibrating bombardment models), for an impactor density of 2.5 g/cm3, 18 km/s impact velocity, 45 deg impact angle (see Methods).
