* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Home -> Astronomy News -> Meteorite News -> Osmium isotopes
Post Info TOPIC: Osmium isotopes
Blobrana


L

Posts: 131433
Date:
RE: Osmium isotopes
Permalink  
 

Scientists have developed a new way of determining the size and frequency of meteorites that have collided with Earth.
Their work shows that the size of the meteorite that likely plummeted to Earth at the time of the Cretaceous-Tertiary (K-T) boundary 65 million years ago was four to six kilometres in diameter. The meteorite was the trigger, scientists believe, for the mass extinction of dinosaurs and other life forms.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

Osmium isotopes in seawater sediment can be used to reveal ancient meteorite strikes, US-based scientists say. The sensitive technique could provide more details on the size of extraterrestrial rocks which have plunged into the sea and vaporised, leaving no crater-shaped calling card behind.  
Geochemists routinely measure the sediment concentrations of elements such as iridium, in order to infer the presence of meteorites. High levels in ocean sediment indicate that a rock with unnatural concentrations of the element must have dissolved in the sea millions of years ago. But iridium concentrations in seawater vary naturally around the globe, so many monitoring sites are needed.

Read more

__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
Home -> Astronomy News -> Meteorite News -> Osmium isotopes


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard