Dinosaurs don't look up

Is history repeating itself?

Courtesy of Imperial College, London

There are a lot worse places to be on Christmas Eve than Chamonix. Our children would have left, happy after a week’s skiing in near perfect conditions, but Monsieur Macron had had other ideas, for health reasons of course.

After spectating an avant-garde procession through Chamonix town and hanging around in a park with makeshift stage and disco lights waiting for Father Christmas, who was great and spoke French like a true Frenchman, amazing, we retired to warm-up and get out of the rain.

(Any skiers reading this will already know, there is nothing much worse in a ski resort than rain. Only no snow). Thank goodness there was beaucoup de neige and it was Christmas.

Netflix

All credit to Netflix. Unlike Amazon Prime, we were able to use our login details and access our account which meant the premier of Don’t Look Up , starring Jennifer Lawrence and Leonardo DiCaprio was available to watch at no extra cost. Amazon insisted on a more Gallic view, adding cost to everything that looked vaguely Christmassy and watchable, despite being logged into our UK account.

Don’t Look Up

Egg nog at the ready, It’s a Wonderful Life, discarded for another year, we settled down to watch this star-studded premier instead. It was easy to understand why it has polarised opinion. Adam McKay wrote the story of a cataclysmic asteroid event destroying life on earth as a parody of the hopeless situation we find ourselves in now and our collective inability to come together to solve the looming climate crisis.

I like armageddon-type films, what-if scenarios explored in detail for our entertainment. World War Z springs to mind with Brad Pitt, although there must have been others since 2013 when that was released?

Don’t Look Up starts in a similar serious fashion, deliberately more pedestrian, as a group of nerds realise exactly what Jennifer Lawrence has discovered in their observatory. The fact that the danger is a genuine possibility and not a zombie apocalypse, adds a helpful veneer of reality. Unfortunately, it isn’t for long and any real sense of dread is stripped away as we flip into Zombieland Double Tap with Woody Harrelson, except it’s not as funny.

Cameo roles by Meryl Streep, the US President and her Chief of Staff and son, Jonah Hill, take a hefty swipe at The Donald, while TV presenters, Cate Blantchett and Tyler Perry, capture the skit of TV news channels which worry more about viewing figures and in this case, try to avoid the news entirely.

It’s a near miss for me, which is more than can be said for the asteroid. I became less interested and more distracted as the movie unwound towards the end.

Asteroids are a real threat

Asteroids do collide with earth on a reasonably regular basis. One of the reasons I wrote recently about NASA’s science experiment which launched in November. The objective, to deliberately try and change the orbit of an asteroid by smashing a satellite into it. Don’t worry, it’s not headed for earth. Scientists currently have a list of 27,000 near earth objects (NEO) and the PHO’s, the potentially hazardous ones, exceeding 140 metres in size, are carefully monitored.

Final year geology student

For part of my degree, I had to make a presentation to fellow students plus lecturers and professors who cared to attend. It was held in their staff common room, a place we had recently been given access to as final year students. Perhaps the department thought we’d earned our place to drink tea and sit on comfy chairs, having completed 2 years of study and were now in the final, squeaky bum one?

I chose the extinction of the dinosaurs, one of the best mysteries of all in the geological record. These enormous, largely cold-blooded reptiles had been roaming our planet for 165 million years before they disappeared overnight, at least in geological time. For comparison, if you include bones of primitive Homo sapiens, we’ve only just arrived at 300,000 years.

Gold is 40 times more abundant than Iridium

40 years ago, the pieces of the puzzle were only just beginning to come together when I made my presentation. A big breakthrough came with a chemical element called Iridium. It’s a super hard, silvery-white metal of the platinum group, which is found in much higher quantities in asteroids, than the earth’s crust. Gold is 40 times more abundant than Iridium on earth. However, at a now famous geological boundary between the Cretaceous and Paleogene periods of geological time, 66 million years ago, there is a thin layer of iridium-rich clay, which has been found in many parts of the world.

Courtesy of New Scientist. The Barringer or Meteor crater in Arizona is small, at 1200 metres across.

It must have been a huge asteroid to cause such a significant extinction of the non-avian dinosaurs (the bird-like ones survived). But if that were the case, why was there no evidence of an impact crater?

Other geologists have argued that the iridium was volcanic in origin, because the Earth’s core is richer in this element than the crust. Volcanic activity on a huge scale could have filled the earth’s atmosphere for years with heavy ash clouds which obscured the sun. Was this enough to make the planet colder, ensuring that vegetation growth slowed, killing off herbivores which meant less food for the carnivores. Large, cold-blooded dinosaurs would have also struggled to regulate their temperature, especially if it got colder.

The Chicxulub crater, Yucatan Peninsula

What has been discovered, since my presentation, is a massive crater which is buried on the seafloor off the coast of Mexico. The asteroid was between 10-15km across, but the size of the impact crater is 150km. The concentration of iridium is 4 times higher around this crater than the surrounding area and is now regarded as the most likely event to have caused this mass extinction.

Three quarters of life on earth was wiped out. Any land animal over 25kg in weight, gone. The speed of the impact created a huge blast wave and heatwave as the asteroid vapourised, throwing vast amounts of debris into the earth’s atmosphere. Anything vaguely close to the impact zone disappeared in less than a second. The sun was not completely blocked out, but it did impact plant growth which started the process of extinction.

Life elsewhere didn’t immediately disappear. A bit like climate change it would have taken a few thousand years before all the dinosaurs died out. Not dissimilar to the dinosaurs at the top of the food chain today.