Happy Asteroid Day, and happy Meteor Watch Day!
Thousands of years ago, the world-famous Willamette meteorite, traveling some 64,000 kilometers per hour, crashed into Earth’s surface. Billions of years before that, an early planet orbiting the Sun was shattered, perhaps in a collision with another protoplanet. While planets including Earth gradually formed and matured, the fragment orbited the Sun. Eventually, it landed in Oregon just outside of what is today the city of Portland. Over many centuries, rainwater interacting with its iron sulfide deposits produced sulfuric acid, which slowly etched and carved large cavities.
The Willamette is made of iron and weighs 15.5 tons. It is the largest ever found in the United States and the sixth-largest in the world. Only about 600 of the 25,000 meteorites found on Earth are made of iron. The material was created deep inside stars, which produce energy by fusing lighter elements into heavier ones – for example, hydrogen into helium. The force of nuclear fusion eventually shatters stars much more massive than our Sun, casting fused elements, such as iron, into interstellar space. Over eons, these elements collect inside clouds of gas and dust.
Within such an iron-rich interstellar cloud, our Sun formed 4.5 billion years ago, giving rise to comets, asteroids, planets and all life on Earth. So when we study the Willamette meteorite, we are also studying the chemical record of our origins and our place in the universe.
Wow astreriod
Heh … I grew up a couple blocks away from the Museum, and touched this meteor every Saturday, for years and years.
John Jainschigg I am glad I was not present at its arrival, as it is fairly terrifyingly large.
The only object “from space”, that I’ve touched, was a Gemini capsule that had been in orbit. It is on exhibit at the Technology Museum in Oslo. How any sane being would volunteer to sit in that minimalistic space vehicle on top of tons and tons of explosive fuel, built by lowest bidder, is mindboggling!
I would really like to see a life history of a nickle-iron meteorite, as a video, perhaps done backwards to point of origin.
I’m also fascinated by the process by which the material formed in stellar fusion becomes the chunks we experience — I have a hard time believing that this lump of iron annealed itself after getting burped from a star and cooling to hardend iron dust. More likely that some swirl was ejected and managed to congeal and pool. Hrm. Maybe under the influence of magnetic fields which are getting shredded as the source sun novas.
Which means that what you’re looking at here might directly be frozen star.
(As would individual chunks of, say, a carbonaceous chrondite.)
The other possiblity being that the forging happened in some proto-planetoid of sufficient mass, which got its outer crust knocked off in a billiards game.
And … yes, this turns out to be somewhat interesting. Fairly dynamic to boot.
youtube.com – Petascale Supernova Simulation