Ancient raindrop fossils shed light on early atmosphere
Description:
Fossilized imprints of raindrops that were sealed into stone 2.7 billion years ago indicate that Earth's early atmosphere could have been packed with greenhouse gases, according to new research that addresses a long-standing paradox of the planet's early history. About 2 billion years ago, the young sun was far less bright, emitting less than 85% of the light and heat it puts out today. With such weak sunlight, Earth should have remained frozen. But ancient water-damaged rocks and algae-like fossils show clear evidence that there was indeed liquid water in the distant past. [Source: Los Angeles Times]
