Read more<\/strong><\/strong><\/h3> - Biggest craters in the Solar System<\/strong><\/em><\/a><\/li>
- Richat structure from space<\/strong><\/em><\/a><\/li>
- India’s Luna Crater<\/strong><\/em><\/a><\/li> <\/ul> <\/div>
Credit: NASA <\/figcaption> <\/figure> <\/div> <\/div> To find out more about its discovery we spoke to Veronica Bray, a planetary scientist from the University of Arizona who uses computer modelling and theoretical analysis to understand impact craters.<\/p> ![\"Veronica](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2024\/11\/veronica-bray.jpg\")
<\/figure> What was the Chicxulub impact?<\/strong>\u00a0<\/h2> It\u2019s believed that a massive asteroid impact 66 million years ago killed around 75% of life on Earth, including the dinosaurs.<\/p>
It formed the Chicxulub crater on the Yucat\u00e1n Peninsula in Mexico.<\/p>
Compared to Nadir\u2019s 9km diameter, Chicxulub is around 200km (124 miles) across. When the asteroid that formed Nadir hit, it would have caused local devastation.\u00a0<\/p>
For Chicxulub, the devastation was global. It would have ejected so much rock ash into the atmosphere that it would have assisted the cooling of Earth for years.<\/p>
Super-hot ejected material would have rained down, heating Earth\u2019s surface, while dust from the crater would blot out the Sun, leading to freezing global conditions.<\/p>
It was the resulting long-term changes to Earth\u2019s climate that eventually allowed warm-blooded creatures to take their place at the top of the food chain.\u00a0<\/p> ![\"Artist's](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2021\/09\/GettyImages-713781277.jpg\")
Artist’s impression of the Chicxulub asteroid impact that wiped out the dinosaurs. Credit: Mark Garlick \/ Science Photo Library \/ Getty Images <\/figcaption> <\/figure> How did you study the Nadir crater?<\/strong><\/h2> Our research involved modelling the full structure of an impact crater.<\/p>
On other planets and moons, we can only see the top of a crater, so we don\u2019t have any idea about the subsurface.<\/p>
On Earth, it\u2019s usually the opposite: the crater\u2019s surface is eroded or covered, but we have seismic data to give us an idea of its structure.<\/p>
Luckily, we have high-resolution seismic data about Nadir crater, initially taken for oil and gas prospecting.<\/p> ![\"A](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2021\/09\/Chicxulub-crater-map-be3ef2e-e1632210648786.jpg\")
An illustration showing the location of the Chicxulub crater, shortly after its formation. The Chicxulub crater is thought to be the impact scar left over from the asteroid that wiped out the dinosaurs and other species on Earth. Credit: Mark Garlick \/ Science Photo Library <\/figcaption> <\/figure> Is Nadir an impact crater?<\/strong><\/h2> By simulating different impacts, we showed that Nadir has the properties expected for a marine impact crater.<\/p>
To further confirm this, we need to find physical evidence of a tremendous shock in Earth\u2019s surface by drilling into Nadir and looking at the rocks.<\/p>
If it is an impact crater, we expect to find rock textures left over from the passage of a shockwave.<\/p>
In shocked quartz, for example, you get crisscrossing features which only form at extremely high pressures.<\/p>
These pressures can also melt or vaporise rock, so melted rocks are another indicator.<\/p>
What makes Nadir unique?\u00a0<\/strong><\/h2> There are only about 200 impact craters that we know of on Earth, and many of them are eroded or buried by plate tectonics and active weather.<\/p>
Nadir is buried under sediment, so has been preserved.<\/p>
By studying Nadir, we can learn about the impact that caused it, the devastation that followed and its potential relationship to the Chicxulub impact.<\/p> ![\"Map](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2024\/11\/nadir-crater-location.jpg\")
Map and regional seismic sections showing location of Nadir Crater. Credit: Uisdean Nicholson, Veronica J. Bray, Sean P. S. Gulick and Benedict Aduomahor <\/figcaption> <\/figure> Did Chicxulub and Nadir happen around the same time?<\/strong><\/h2> When we collected 3D seismic data of Nadir, some samples of the rock cores were collected.<\/p>
In these rock samples, the deeper layers are the oldest rocks, so can be linked to different ages in Earth\u2019s history.<\/p>
From that, we could work out the general age of the crater. If we can drill into the crater, we can more accurately determine the crater\u2019s age throug a process called radiometric dating.\u00a0<\/p> ![\"Impact](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2019\/05\/Jupiter-impact-zones-comet-80a702f.jpg\")
Impact zones on Jupiter created by Comet Shoemaker-Levy 9. Nadir and Chicxulub may have been similar events.\u00a0Eight impact sites are visible. Credit: Hubble Space Telescope Comet Team and NASA\/ESA <\/figcaption> <\/figure> What can the craters tell us about the relationship between the impacts?<\/strong><\/h2>
To find out more about its discovery we spoke to Veronica Bray, a planetary scientist from the University of Arizona who uses computer modelling and theoretical analysis to understand impact craters.<\/p> It\u2019s believed that a massive asteroid impact 66 million years ago killed around 75% of life on Earth, including the dinosaurs.<\/p> It formed the Chicxulub crater on the Yucat\u00e1n Peninsula in Mexico.<\/p> Compared to Nadir\u2019s 9km diameter, Chicxulub is around 200km (124 miles) across. When the asteroid that formed Nadir hit, it would have caused local devastation.\u00a0<\/p> For Chicxulub, the devastation was global. It would have ejected so much rock ash into the atmosphere that it would have assisted the cooling of Earth for years.<\/p> Super-hot ejected material would have rained down, heating Earth\u2019s surface, while dust from the crater would blot out the Sun, leading to freezing global conditions.<\/p> It was the resulting long-term changes to Earth\u2019s climate that eventually allowed warm-blooded creatures to take their place at the top of the food chain.\u00a0<\/p> Our research involved modelling the full structure of an impact crater.<\/p> On other planets and moons, we can only see the top of a crater, so we don\u2019t have any idea about the subsurface.<\/p> On Earth, it\u2019s usually the opposite: the crater\u2019s surface is eroded or covered, but we have seismic data to give us an idea of its structure.<\/p> Luckily, we have high-resolution seismic data about Nadir crater, initially taken for oil and gas prospecting.<\/p> By simulating different impacts, we showed that Nadir has the properties expected for a marine impact crater.<\/p> To further confirm this, we need to find physical evidence of a tremendous shock in Earth\u2019s surface by drilling into Nadir and looking at the rocks.<\/p> If it is an impact crater, we expect to find rock textures left over from the passage of a shockwave.<\/p> In shocked quartz, for example, you get crisscrossing features which only form at extremely high pressures.<\/p> These pressures can also melt or vaporise rock, so melted rocks are another indicator.<\/p> There are only about 200 impact craters that we know of on Earth, and many of them are eroded or buried by plate tectonics and active weather.<\/p> Nadir is buried under sediment, so has been preserved.<\/p> By studying Nadir, we can learn about the impact that caused it, the devastation that followed and its potential relationship to the Chicxulub impact.<\/p> When we collected 3D seismic data of Nadir, some samples of the rock cores were collected.<\/p> In these rock samples, the deeper layers are the oldest rocks, so can be linked to different ages in Earth\u2019s history.<\/p> From that, we could work out the general age of the crater. If we can drill into the crater, we can more accurately determine the crater\u2019s age throug a process called radiometric dating.\u00a0<\/p> <\/figure> What was the Chicxulub impact?<\/strong>\u00a0<\/h2>
How did you study the Nadir crater?<\/strong><\/h2>
Is Nadir an impact crater?<\/strong><\/h2>
What makes Nadir unique?\u00a0<\/strong><\/h2>
Did Chicxulub and Nadir happen around the same time?<\/strong><\/h2>
What can the craters tell us about the relationship between the impacts?<\/strong><\/h2>