Precision Fermentation: Catastrophe Lifeline
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Loading... - Graca Alessandro
- 07 Apr 2023
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On Saturday Asteroid 2023 DZ2 flew by our planet at 27,000 km per hour, closer to us than it was to the Moon.
It was less than one-hundredth of the diameter of the gigantic asteroid that took down the dinosaurs and most other animals 66 million years ago (75% of land species extinct), but it would still have killed a large city with a direct hit.
“While close approaches are a regular occurrence, one by an asteroid of this size (50-100 metres in diameter) happens only about once per decade, providing a unique opportunity for science,” said officials with NASA's Planetary Defense Coordination Office. But even the scientists would not welcome an asteroid ten times as big as 2023 DZ2.
Most scientists used to believe that such big rocks hit Earth on average only once every 600,000-700,000 years. That figure has to be based on studies of how big and how fresh craters are on the Moon and Mars, however, because wind and water quickly erode the evidence of most asteroid strikes on Earth.
Now there’s a new study out that suggests strikes in the one-km range happen much more often. James Garvin, chief scientist of NASA’s Goddard Space Flight Center, recently led a research team that says the big hits may happen up to a dozen times per million years. Bad news, he explained: “It would be in the range of serious crap happening.” A one-km-wide asteroid would boost megatons of vapourised rock into the stratosphere, where it would stay for years and block some of the incoming sunlight. Read More…
