At about 10 o’clock on the night of Feb. 28, 2021, a fireball streaked through the sky over England. The blazing extraterrestrial visitor was seen by more than 1,000 people, and its descent was filmed by 16 dedicated meteor-tracking cameras from the UK Fireball Alliance and many dashboard and doorbell cams.
With the time difference to Australia, the Global Fireball Observatory team at Curtin University were the first to dig into their cameras’ data, quickly realizing there may be very special meteorites to find around the town of Winchcombe, Gloucestershire.
The next morning’s news told people in the area to look out for black rocks in their garden. The Wilcock family discovered a pile of dark powder and small rocky pieces on their driveway. They called in specialists from the Natural History Museum who confirmed it was a meteorite and collected the space rubble for further analysis, all within 12 hours of it landing.
More fragments were collected from the surrounding area over the next month. All told, the samples added up to around 1.3 pounds (600 grams) of exceptionally pristine asteroid rock from the outer solar system.
We have been studying this precious find with colleagues from around the world for the past 18 months. As we report in a new paper in Science Advances, it is a very fresh sample of an ancient rock formed in the early years of the solar system, rich in the water and organic molecules that may have been crucial in the origin of life on Earth.
How to catch a fireball
Meteorites are rocks from space that have survived the fiery descent through our atmosphere. They are the remnants of our (very) distant past – around the time the planets were formed, holding clues to what our solar system was like billions of years ago.
There are more than 70,000 meteorites in collections around the world. But the Winchcombe meteorite is quite a special one.
Why? Well, of all the meteorites ever found, only around 50 have ever been seen falling with enough precision to calculate their original orbit – the path they took to impact Earth. Figuring out the orbit is the only way to understand where a meteorite came from.
The Global Fireball Observatory is a network of cameras on the lookout for falling meteorites. It is a collaboration of 17 partner institutions around the world, including Glasgow University and Imperial College in the UK. This collaboration grew out of Australia’s Desert Fireball Network, run by Curtin University. Of the few meteorite samples with known origins, more than 20 percent have now been recovered by the Global Fireball Observatory team.
Tracking the Winchcombe meteorite
The Winchcombe meteorite was one of the most well observed yet. All these observations helped us determine this special sample came from the main asteroid belt, between Mars and Jupiter.
Observing a fireball from a network of cameras means we can recreate the rock’s path through the atmosphere and not only calculate its orbit, but also its fall to the ground.