A bit of obscure history today—on August 10th, 1972, a meteorite surged into our atmosphere and came within 35 miles of the Earth’s surface.
As it blasted across North America’s skyline at 15 km a second, many surprised citizens looked up in shock.
Whilst a spectacular sight, it was later estimated, had it hit the planet, it would have exploded with the power of several nuclear bombs. A near miss, so let’s celebrate this meteoric occasion of old with a look at these speedy things.
1972 Great Daylight Fireball
A lady called Linda Baker filmed the meteorite in amateur footage later praised for providing key insights into its trajectory, velocity, and psycho rating.
The meteor was an Earth-grazing fireball. It blasted into the atmosphere above Utah around 2:30pm.
It came within 57 kilometres (35 miles, which is 187,000 feet) of striking the Earth. And many who observed it reported a considerable double sonic boom as it stormed along at 15 kilometres per second.
In 1999, we watched a BBC Horizon documentary called New Asteroid Danger (you can watch it on that link, if you wish) that brought our attention to this thing.
The documentary had been updated from an episode in the early 1990s.
More recently, as in the 10th August 2022, various space agencies marked the 50th anniversary since it hurtled through the sky.
The #GreatDaylightFireball☄️entered Earth’s atmosphere at a very shallow angle and didn’t lose sufficient energy to be captured by Earth’s gravity and fall to the ground. It is thought the #asteroid had a diameter of ~10m. It hasn’t been seen since.
©️James Baker, 1972, Wyoming pic.twitter.com/2FXLFLwurG
— ESA Operations (@esaoperations) August 10, 2022
The fact it’s saved for posterity is rather lucky. In the early ’70s, home video cameras were still pretty rare. So to have someone with one around to observe the fireball, and to film it so steadily as it erupted into view, is a stroke of most excellent good fortune.
Amazingly, there’s also a second recording of the event.
State the obvious mode—it was recorded on the same day! August 10th, 1972, recorded in Alberta of Canada.
Near misses like this must have been remarkably common for the Earth over millions of years. Most of them undocumented and unknown.
We got very lucky with this one. Had the 1972 Great Daylight Fireball hit Earth, the course of our modern history could well have changed significantly.
Earth’s Encounters With Big Rocks From Space
The Alvarez hypothesis was first postulated in 1980. That was by Luis Walter Alvarez (1911-1988), his son, as well as chemists Frank Asaro and Helen Vaughn Michel.
They discovered an enormous amount of iridium across the world from the Cretaceous-Paleogene boundary.
In the scientific community, Alvarez was ridiculed for the hypothesis. But (as you no doubt know!), it’s now pretty much the accepted theory for the end of the dinosaurs.
Unless you think it was killer aliens. Or something.
Eugene Shomaker (1928-1997) helped Alvarez’s theory enormous. A founder of planetary science, he confirmed the below hole in the ground to have been created by a meteorite 50,000 years ago. Previously, it was thought to be a long collapsed volcano.
Shomaker was one of the leading scientists of his era to suggest this was a very real possibility.
His work argued an asteroid hitting the planet would be devastating. Now, there wasn’t really much evidence for that. Until Comet Shoemaker–Levy 9 collided with Jupiter between 16th and 22nd July, 1994.
The comet was discovered by Eugene and his wife Carolyn, as well as Canadian astronomer David Levy. The impact, covered extensively by the media, was global front page news.
Recorded speeds of the comets hitting Jupiter were as high as 216,000 km/h (134,000 mph). That is some scary crap right there.
Due to these events, scientists began digging around through historical records.
Incidents such as the Tunguska Event of 1908 and the 1930 Brazilian equivalent were soon discovered. The latter was reported by Catholic missionary Father Fidello, who happened to be on the scene.
There’s also the Bonilla Observation of 1883—it was rediscovered and cast in a new light.
It’s the most alarming as it was believed to be a billion-tonne comet that missed Earth by a few hundred kilometres.
You can see José Bonilla’s photograph below, he used an early photographic technique called the collodion process.
What all of these discoveries highlighted for scientists was smaller asteroids were also incredibly destructive.
You didn’t need a dinosaur ending, Mount Everest sized SOB to cause significant worry. A meteor the size of a car could wreak havoc on any major city.
However, these sorts of impacts are still very rare.
Frankly, humanity poses a bigger threat to itself than rocks hurtling through space. But it’s still fascinating to track the sky and keep an eye on them, as they’re relics from the distant past of the Universe.
Many are discovered and tracked by the Minor Planet Center (MPC) and Jet Propulsion Laboratory’s Center for Near Earth Object Studies (CNEOS).
This has allowed us to even name these colossal things, blasting for eternity through space with a type of serene lunacy.
Toutatis is first up. Discovered by Christian Pollas in 1989, and named via Celtic mythology, this is a potentially hazardous, elongated asteroid that’s bloody enormous and moving very rapidly.
It apparently has an “eccentric” path through space—a “chaotic orbit”, as it were. In 2012, it came within 18 lunar distances of Earth—one lunar distance is about 400,000 km, so we were quite safe. NASA was able to film it as it stormed along (see the above video).
Remarkably, also in December 2012, the Chinese deep space probe Chang’e 2 flew within two miles of the thing!
Eerie pictures revealed a dumbbell-shaped rock that has spent millions of years surging through space at 6.67 miles per second.
As a collision risk it’s minimal, with its last “nearby” pass in 2016. It won’t be a hazard to Earth for at least 600 years, having had its orbit mapped extensively, with its next close approach being in 2069.
There’s a chance it may be engulfed by Jupiter as it blasts through space, as its trajectory will bring it to within two AU (astronomical units) of the gas giant at some points in the future. Cripes.
Geographos is a 2.5 kilometre asteroid—it’s potentially hazardous to Earth. It was discovered in 1951 and it’s named in honour of the National Geographic Society.
Its closest effort with hanging out with us here on Earth was in 1994, which won’t be improved upon until 2586.
NASA’s Clementine mission was intended to get up close and personal with the asteroid, but a technical failure ensured we were left with merely the sight of a small dot speeding along against a black background.
Still, quite the fitting description for this bleak, but glorious, monstrosity, oui?
In May 1983, Comet IRAS–Araki–Alcock launched a successful sneak attack. It completed the closest known approach to Earth by any comet in 200 years.
It came within 0.0312 AU (4,670,000 kilometres—2,900,000 miles) of Earth. That’s closer to our planet than the Moon is.
Two amateur astronomers made the discovery, both of whom were schoolteachers.
And they came across it only two weeks before it blasted by our bit of the Universe. It has an orbital period of over 970 years, so it’s not doing this little number on us again for a while.
Should You Be Terrified?
Not really, no. Our stance on this is they could cause a cataclysmic event. But history shows supermassive impact events are incredibly rare.
An asteroid impact almost certainly ended it for the dinosaurs.
But more regular major events like that didn’t follow repeatedly. Otherwise, the evolution of life as we know it wouldn’t have come to be. Frankly, we think the likes of the following are a much bigger threat:
- Climate change
- Various types of eco-catastrophe
- Nuclear war
- General stupidity
These are all a much bigger threat to humans than a potential major impact event 50 million years from now.
In other words—aim your terror in more appropriate directions.