Up until the recent breakthrough of theasteroid 2024 YR4 , which at the time of composition has an estimated 1.6 per centum chance of hitting us next decade , the most dangerous space rock to us was asteroid Bennu . Bennu was visit and sampled by NASA ’s OSIRIS - king and datum from it is revolutionizingour understanding of the early solar arrangement – but what would happen if this medium - sized asteroid were to defy the betting odds and hit our planet ? It become out , quite a lot !
Bennu has a diameter of roughly 500 meters ( 1,640 animal foot ) and has a 1 in 2,700 chance of hitting our planet in September 2182 . Bennu is not on the scale of theChicxulub impactor – which hit the Earth at the last of the Cretaceous and spelled the end of the non - avian dinosaur and many other species – but it is also not small . Depending on the collision parametric quantity , it could cause regional to large - musical scale price .
scientist have investigated possible scenario , focusing alone on the deposition of dust in the atmosphere . Even without consider the effects of the smut and sulphur if the asteroid hits land , the way through the atmosphere will give plenty behind to impress our planet .
A hit would deposit large quantities of junk in the stratosphere , more than during the Chicxulub result . Bennu would not be moving as chop-chop through the atm and would pull up stakes more behind . In the worst - case scenario , 400 million lashings of dust get shoot into the atmosphere , causing an wallop wintertime . globose temperatures could drop by 4 ° C ( 7.2 ° F ) , the ozone level would fall by a third , and there would be 15 percent less pelting and snow .
The theme of the dust also matters . In general , there would be a dramatic drop-off in photosynthesis , with famine and death across the whole intellectual nourishment chain . The team estimated that the terrestrial net primary productivity ( NPP ) could plummet by up to 36 per centum , while marine NPP could drop by up to 25 per centum . However , dust rich enough in iron could really causediatoms – microalgae – to experience a spectacular salad days in the Pacific Ocean for three years .
" Asteroid impacts have taken lieu many times in Earth ’s history . Our former human ancestors may have experienced some of these planet - shifting events before with possible impacts on human development and even our own inherited physical composition , ” co - comparable author Lan Dai , from the Center for Climate Physics , Institute for Basic Science in Busan , said in astatement . “ This study provides the ground to measure the possible effect of abrupt events on early human evolution . ”
The work is an interesting windowpane into the possible action of medium - sized asteroid collisions and how they might have globe - traverse effects – even if the impact itself touch a smaller locality .
A newspaper describing the findings is published in the journalScience Advances .
