It’s generally accepted that whatever created the 180km wide Chicxulub crater in Mexico was the giant rock that wiped out all non-bird-like dinosaurs around 65 million years ago. However there’s a new suggestion that it may not have been an asteroid, but a comet.
The reason behind this thinking was outlined at the 44th Lunar and Planetary Science Conference, where the focus of interest was the sediments deposited by the impact. These sediments occur globally, therefore we know there was a great upsurge of dust and debris from the impact, but according to new research, the amount of iridium kicked up was much less than initially stated.
This would suggest a smaller body hit the earth back then, but that would need to be something travelling far faster if it was to claim responsibility for creating the giant crater. The suggestion from scientists, is that it could well have been a comet instead.
“You’d need an asteroid of about 5km diameter to contribute that much iridium and osmium. But an asteroid that size would not make a 200km-diameter crater,” said Dr Jason Moore, from Dartmouth College in New Hampshire, while speaking with the BBC.
“So we said: how do we get something that has enough energy to generate that size of crater, but has much less rocky material? That brings us to comets.”
Not everyone agrees with this finding however, which relies on the global distribution of the impactor’s matter. Some studies claim as much as 70 per cent was distributed around the world, whereas others only 20 per cent. If it was the latter, an asteroid could still be responsible.
KitGuru Says: While it seems there isn’t quite a consensus about how this went down just yet, I think we can all agree it’s about time we had Jurassic Park style dinosaur Zoos. Can we sort out cloning those bad boys yet? I’m fed up of waiting.