Ancient Meteorite Was a 'Fertilizer Bomb' for Life on Earth
2024-10-28
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1The space rock that hit Earth 66 million years ago and caused the deaths of many life forms - including dinosaurs - was not the largest object to ever strike our planet.
2One meteorite up to 200 times bigger hit the planet 3.26 billion years ago, causing worldwide destruction.
3But, as new research shows, that event may have been helpful for the early development of life.
4The meteorite may have served as "a giant fertilizer bomb."
5In other words, it may have supplied the key nutrients phosphorus and iron for the bacteria and other organisms that existed at the time.
6Researchers studied the effects of this meteorite strike using evidence from ancient rocks in an area in northeastern South Africa.
7The area is called the Barberton Greenstone Belt.
8Researchers found many signs that life quickly came back after the strike.
9"Life not only recovered quickly once conditions returned to normal within a few years to decades, it actually thrived," said Nadja Drabon of Harvard University.
10Drabon was the lead writer of the study that appeared recently in the scientific publication Proceedings of the National Academy of Sciences.
11Earth was a much different place when the meteorite strike took place.
12At the time, during the Paleoarchean Era, meteorite strikes were larger and more common.
13"At this time, Earth was something of a water world... There was essentially no oxygen gas in the atmosphere and oceans, and no cells with nuclei," said study co-writer Andrew Knoll.
14The meteorite was rich in carbon and also contained phosphorus.
15Its diameter was around 37-58 kilometers, Drabon said, meaning its mass was 50 to 200 times the mass of the asteroid that killed the dinosaurs.
16The effects of the hit, or impact, would have been quick and serious, Drabon suggested.
17The impact force would have caused a dust storm that circled the world and turned the sky black within hours, she explained.
18It also would have likely had a big effect on the ocean and created a lot of heat, possibly boiling the upper part of the oceans.
19Drabon said it probably would have taken years for the dust to settle and for the atmosphere to cool enough for the water vapor to return to the ocean.
20But the meteorite would have contained a large amount of phosphorous.
21It is an important nutrient for molecules central to storing and sharing genetic information.
22Powerful ocean waves also would have mixed iron-rich deep waters into shallower waters, creating a good environment for many kinds of microbes.
23Iron provides microbes with an energy source.
24"Imagine these impacts to be giant fertilizer bombs," Drabon said.
25"We think of meteorite impacts as being disastrous," Drabon said.
26"But 3.2 billion years ago, life was a lot simpler."
27"Microorganisms are relatively simple, versatile, and they reproduce at fast rates," Drabon added.
28The evidence of the hit included chemical signatures of the meteorite, small circular structures formed from rock melted by the impact, and pieces of seabed mixed with other debris in sedimentary rock.
29"Early life was resilient in the face of a giant impact," Drabon said.
30I'm John Russell.
1The space rock that hit Earth 66 million years ago and caused the deaths of many life forms - including dinosaurs - was not the largest object to ever strike our planet. 2One meteorite up to 200 times bigger hit the planet 3.26 billion years ago, causing worldwide destruction. But, as new research shows, that event may have been helpful for the early development of life. 3The meteorite may have served as "a giant fertilizer bomb." In other words, it may have supplied the key nutrients phosphorus and iron for the bacteria and other organisms that existed at the time. 4Researchers studied the effects of this meteorite strike using evidence from ancient rocks in an area in northeastern South Africa. The area is called the Barberton Greenstone Belt. 5Researchers found many signs that life quickly came back after the strike. 6"Life not only recovered quickly once conditions returned to normal within a few years to decades, it actually thrived," said Nadja Drabon of Harvard University. 7Drabon was the lead writer of the study that appeared recently in the scientific publication Proceedings of the National Academy of Sciences. 8Earth was a much different place when the meteorite strike took place. 9At the time, during the Paleoarchean Era, meteorite strikes were larger and more common. 10"At this time, Earth was something of a water world... There was essentially no oxygen gas in the atmosphere and oceans, and no cells with nuclei," said study co-writer Andrew Knoll. 11The meteorite was rich in carbon and also contained phosphorus. Its diameter was around 37-58 kilometers, Drabon said, meaning its mass was 50 to 200 times the mass of the asteroid that killed the dinosaurs. 12The effects of the hit, or impact, would have been quick and serious, Drabon suggested. 13The impact force would have caused a dust storm that circled the world and turned the sky black within hours, she explained. It also would have likely had a big effect on the ocean and created a lot of heat, possibly boiling the upper part of the oceans. 14Drabon said it probably would have taken years for the dust to settle and for the atmosphere to cool enough for the water vapor to return to the ocean. 15But the meteorite would have contained a large amount of phosphorous. It is an important nutrient for molecules central to storing and sharing genetic information. 16Powerful ocean waves also would have mixed iron-rich deep waters into shallower waters, creating a good environment for many kinds of microbes. Iron provides microbes with an energy source. 17"Imagine these impacts to be giant fertilizer bombs," Drabon said. 18"We think of meteorite impacts as being disastrous," Drabon said. "But 3.2 billion years ago, life was a lot simpler." 19"Microorganisms are relatively simple, versatile, and they reproduce at fast rates," Drabon added. 20The evidence of the hit included chemical signatures of the meteorite, small circular structures formed from rock melted by the impact, and pieces of seabed mixed with other debris in sedimentary rock. 21"Early life was resilient in the face of a giant impact," Drabon said. 22I'm John Russell. 23Will Dunham reported on this story for Reuters. John Russell adapted it for VOA Learning English. 24_________________________________________________ 25Words in This Story 26meteorite - n. a meteor that reaches the surface of the earth without being completely destroyed 27giant - adj. unusually large and/or powerful 28decade - n. a period of ten years 29thrive - v. to flourish, to grow vigorously 30vapor - n. a substance in the gaseous state as distinguished from the liquid or solid state 31versatile - adj. easily changing, having many uses 32resilient - adj. adjusting easily to change or misfortune