December 4, 2012
The imprints of raindrops preserved in 2.7bn-year-old rock are being used to figure out what the atmosphere was like on the early Earth.
Scientists have used the depressions drops left to calculate how fast they were going as they impacted the ground.
This has allowed them to determine the density of air in ancient times.
This “palaeobarometry” approach, revealed at the AGU Fall Meeting, will help constrain the models that try to simulate conditions in Archaean times.