What Impact Space Rock Larger Than the One That Killed Dinosaurs Had on Earth
Asteroid 
A massive meteorite, much larger than the one that supposedly wiped out the dinosaurs, hit our planet millions of years ago and this impact might have had a positive impact on Earth’s biosphere, according to a new study published in the Proceedings of the National Academy of Sciences journal.The meteorite that struck Earth sometime in the Archean Eon (i.e. over 2.5 billion years ago) was 50 to 200 times larger than the one that triggered the aforementioned Cretaceous–Paleogene extinction event, the team of scientists from Harvard and Stanford universities behind the new research postulate.The impact supposedly triggered a massive tsunami that brought the iron-rich deep waters of the Earth’s early oceans to the shallows, and produced “heating that caused partial evaporation of surface ocean waters and likely a short-term increase in weathering and erosion on land,” the study says.The meteorite’s subsequent evaporation also supposedly led to an injection of phosphorus into Earth’s biosphere.
Beyond PoliticsAstronomers Confirm Water Presence on Asteroid Surfaces for the First Time17 February, 17:14 GMTThese effects thus led to a “temporary bloom of iron-cycling microbes” during our planet’s early days.Overall, at least 16 major impacts that involved meteorites larger than ten kilometers in diameter occurred during the Archean Eon, the researchers note.“These impacts probably had severe, albeit temporary, consequences for surface environments. However, their effect on early life is not well understood,” they add.