2.7 billion-year old fossilised raindrops
imprint of raindrop find on John Rock in South Africa show it was raining2.7 billion years ago . Other exposed rock ‘n’ roll in the same area which are more than 3 billion age older contain features associated with flowing or standing H2O , including ripple marks and mud cracks , glassy ' pillow ' lavas and algae - similar microfossils . Indirect evidence advise the planet had terrestrial ocean as early as 4....