Go Back   IceInSpace > General Astronomy > Astronomy and Amateur Science

Reply
 
Thread Tools Rate Thread
  #1  
Old 28-05-2020, 05:34 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,915
Asteroid that created Chicxulub crater arrived at the deadliest possible angle

A 26th May 2020 press release by Caroline Brogan at the Imperial
College London discusses results published in Nature Communications
that suggest the asteroid that struck Chicxulub arrived at the deadliest
possible angle and that the geologic composition of the rocks created
a deadly cocktail for life on Earth at the time.

Quote:
Originally Posted by Caroline Brogan, Imperial College London
New simulations from Imperial College London have revealed the asteroid that doomed the dinosaurs struck Earth at the ‘deadliest possible’ angle.

The simulations show that the asteroid hit Earth at an angle of about 60 degrees, which maximised the amount of climate-changing gases thrust into the upper atmosphere.

Such a strike likely unleashed billions of tonnes of sulphur, blocking the sun and triggering the nuclear winter that killed the dinosaurs and 75 per cent of life on Earth 66 million years ago.

Drawn from a combination of 3D numerical impact simulations and geophysical data from the site of the impact, the new models are the first ever fully 3D simulations to reproduce the whole event – from the initial impact to the moment the final crater, now known as Chicxulub, was formed.

Lead researcher Professor Gareth Collins, of Imperial’s Department of Earth Science and Engineering, said: “For the dinosaurs, the worst-case scenario is exactly what happened. The asteroid strike unleashed an incredible amount of climate-changing gases into the atmosphere, triggering a chain of events that led to the extinction of the dinosaurs. This was likely worsened by the fact that it struck at one of the deadliest possible angles.

“Our simulations provide compelling evidence that the asteroid struck at a steep angle, perhaps 60 degrees above the horizon, and approached its target from the north-east. We know that this was among the worst-case scenarios for the lethality on impact, because it put more hazardous debris into the upper atmosphere and scattered it everywhere – the very thing that led to a nuclear winter.”

The results are published in Nature Communications. The simulations, which used a 17-km diameter asteroid with a density of 2630 kgm3 and a speed of 12 km/s, were performed on the Science and Technology Facilities Council (STFC) DiRAC High Performance Computing Facility.

The upper layers of earth around the Chicxulub crater in present-day Mexico contain high amounts of water as well as porous carbonate and evaporite rocks. When heated and disturbed by the impact, these rocks would have decomposed, flinging vast amounts of carbon dioxide, sulphur and water vapour into the atmosphere.

The sulphur would have been particularly hazardous as it rapidly forms aerosols - tiny particles that would have blocked the sun’s rays, halting photosynthesis in plants and rapidly cooling the climate. This eventually contributed to the mass extinction event that killed 75 per cent of life on Earth.
Full press release including graphics here :-
http://www.imperial.ac.uk/news/19769...iest-possible/

Abstract, "Nature Communications", "A steeply-inclined trajectory for the Chicxulub impact" by Collins et. al. :-
https://www.nature.com/articles/s41467-020-15269-x
Reply With Quote
  #2  
Old 28-05-2020, 07:31 PM
multiweb's Avatar
multiweb (Marc)
ze frogginator

multiweb is offline
 
Join Date: Oct 2007
Location: Sydney
Posts: 22,060
It's hard to imagine when you see those cross sections scales and the corresponding timestamps. The amount and volume of stuff that got shuffled around.
Reply With Quote
  #3  
Old 29-05-2020, 03:02 AM
OICURMT's Avatar
OICURMT
Oh, I See You Are Empty!

OICURMT is offline
 
Join Date: Apr 2010
Location: Laramie, WY - United States of America
Posts: 1,543
Why would they call it a nuclear winter?
Reply With Quote
  #4  
Old 23-06-2020, 05:30 PM
Scorpius51's Avatar
Scorpius51 (John)
Star stuff observer!

Scorpius51 is offline
 
Join Date: Sep 2009
Location: Canberra
Posts: 389
Quote:
Originally Posted by OICURMT View Post
Why would they call it a nuclear winter?
I imagine they are using a little literary license to a parallel with the potential after effects of a nuclear war.
Reply With Quote
  #5  
Old 15-01-2021, 07:59 PM
cannon_gray (Cannon Gray)
Member

cannon_gray is offline
 
Join Date: Dec 2020
Location: Dresden
Posts: 35
According to scientists' calculations, if the asteroid fell to the Earth at an angle of 15 °, the amount of dust, carbon dioxide and sulfur compounds thrown out would be about three times less, and if it fell vertically - an order of magnitude less.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 05:58 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Bintel
Advertisement