Why hasn't an asteroid wiped out mankind?

 A 10-kilometer planet-killer strikes Earth roughly every 100 million years. Humanity has not beaten the odds; at barely 300,000 years old, the species just has not been playing long enough.

Dinosaurs roamed the planet for 165 million years, giving probability millions of chances to deliver a catastrophic impact. In contrast, Homo sapiens arrived just a geological second ago. The odds of a civilization-ending rock intersecting with Earth's orbit during this brief window of human existence are exceptionally low.

Space debris still strikes Earth constantly, but the planet is well-protected. About 100 tons of dust, sand, and small rocks burn up in the atmosphere every day. When larger objects arrive, the atmosphere acts as a formidable shield. A car-sized asteroid hits Earth about once a year, detonating as a spectacular fireball rather than reaching the ground intact. Even an object the size of a football field—which strikes roughly every 2,000 years—would cause significant regional damage but fall far short of an existential threat to humanity.

The solar system itself has settled down considerably since its chaotic early days. Most large debris was swept up, consolidated into planets, or ejected billions of years ago. Jupiter’s immense gravitational pull acts as a stabilizing force, often deflecting long-period comets and rogue asteroids away from the inner solar system or absorbing them entirely, as it did with Comet Shoemaker-Levy 9 in 1994.

Humanity is now actively altering its planetary odds. Astronomers have cataloged more than 95 percent of near-Earth asteroids larger than 1 kilometer in diameter, and none are on a collision course with Earth for at least the next century. Rather than relying entirely on probability, space agencies are developing active planetary defense strategies. Missions like NASA's Double Asteroid Redirection Test (DART) have demonstrated the ability to alter an asteroid’s trajectory by colliding a spacecraft into it, proving that if a threat is discovered, a deflection mission is technologically feasible.

The Barringer Crater in Arizona was created roughly 50,000 years ago by an asteroid approximately 150 feet across, leaving a scar nearly a mile wide. Source: Wikimedia Commons.

What is the greatest waste of money in the history of mankind?

 You are going to be surprised.

1)

Everyone knows this image: it is a great attraction for tourists.

This is the length of the wall: 21,196 kilometers.
It took more than 100 years to build this.
400,000 people died during the construction of this wall.
+ 110 million tons of stone were used
+ There are 25,000 watchtowers.
There is no exact price known for this, but people estimate its value at 350 million euros.

And yes, I am talking about the Great Wall of China !
We can certainly say that it is something beautiful to look at, but like any great stonework, this wall was intended to fulfill its function.
Namely, to protect China against the soldiers from Mongolia in the 13th century.

And guess what happened?
The wall actually did NOTHING to stop the Mongols.

So how did the Mongolians manage to conquer China?
Well, the Mongolians were clever: there were a few open spaces in the wall, because the wall had to go through forests and rocky areas, where it is difficult to build.
It was not possible to build on the ground everywhere.
And as you can guess, the Mongolian troops went through these gaps in the wall.
So it never really fulfilled its function.

So yes, wasted money and human lives.

2)

Do you know why Scotland is part of the United Kingdom?

It is a simpler answer than you think:
Scotland wanted to have a colony in the 17th century.
And in 1698, King William II of Scotland went to make a colony in America, namely in Panama, which is here on the map:

So what did he do?
He spent about 25% of Scotland's economy on this project.
But as you can probably guess, the colony was not a success.
Many Scottish colonists died of disease and of war with Spain, which took over the country.
This left Scotland with a debt of what today corresponds to about 80 million euros. Due to that foolish decision, Scotland plunged into a major crisis, which led to Scotland having to become part of the United Kingdom.

3)

This is the " Basilica of Our Lady of Peace".
This is a Catholic church.
This is in Ivory Coast.
In Ivory Coast, both Muslims and Christians live.
Approximately one-third, or 33%, of the people in this country are Christian.
This basilica is 158 meters high, and the dome of the basilica alone weighs 310 tons.

So what is the problem?
The price to build this was 300 million dollars, or 285 million euros.
This project doubled Ivory Coast's national debt.
Moreover, it costs more than a million euros per year for maintenance.

Was it worth building them then? NO.
It has a capacity of 18,000 people, but barely a few hundred people come to attend mass.
That means it is only 2% or, at best, 3% full.