In 2012, astronaut Longarang performed an AMA on Reddit. Between questions about Aliens (he saw nothing in space) and where his coffee came from (recycled urine), he answered questions about why he should accept the risks of his future mission to Mars. Garan quoted his colleague. “If the dinosaurs had a space program, they would still be here.”
Putting aside the possibility of a giant reptile of walnut-sized brains developing a version of Apollo 11, the point here is that the dinosaurs have almost certainly been wiped out by a six-mile asteroid. survive.
Dinosaurs, of course, could not do anything about the murderer's asteroid other than waving their small arms at their approaching fate. But in their case did I have a space program – and yes, now I'm heading for a rocket like John Glenn, imagining a T. Rex in a space suit The right thing – They may have detected that incoming asteroid decades ago and did something to avoid their fate.
But humans are in a better place – as shown in recent news about an asteroid called YR4 in 2024, it seemed to temporarily threaten the Earth.
Killer Asteroid, a brief explanation
Chicxulub asteroid, which is likely to have wiped out dinosaurs, was not the first time a massive asteroid had collided with Earth. A 12-16-mile wide asteroid hit Earth more than 2 billion years ago. Another 6-10 miles wider hit in Vredefold, South Africa, with Sudbury, Ontario, 1.85 billion years ago. Recently, in 1908, a 130-foot-wide spacelock exploded six miles from Siberia, creating enough strength to knock 80 million trees.
Earth exists in space shooting galleries, and strikes threatening the kind of true civilization seen in such films Deep shock Incredibly rare, they happen. And given enough time, they happen again.
Until recently, Chicxulub-sized asteroids were able to find themselves on the collision course with Earth, but they were unable to do more than the dinosaurs did. The result is global fires, massive earthquakes, and potentially megatuna misses, followed by a shock that wipes out global food supplies. Something very bad.
But we are no longer helpless.
Like many cool things, the field of asteroid defense started with lots of kids at MIT with plenty of brain power. In 1967, MIT Professor Paul Sandorf asked the class to imagine a real asteroid called Icarus, which astronomers already identified, would hit Earth in the near future. And it was their job to devise ways to save the world. (In real life, the asteroid came within 4 million miles of Earth. It's 15 times the distance between the planet and the moon, but by cosmic standards it's a close shaving.)
The birth of Project Icarus was born. Students have created a plan to launch six Saturn V-rockets, each carrying a 100 megaton nuclear warhead on an asteroid. The warhead explodes near an asteroid, creating enough power to change its trajectory and allow the Earth to escape.
For all careful engineering, “Project Icarus” was primarily science fiction. Among other inconveniences, the largest nuclear bomb ever made was only 50 megatons of power. At the time, our space science was so rudimentary that there was no way to reliably identify potentially dangerous asteroids very far, and there was no real way to deflect them.
However, Project Icarus has made its asteroid defense ideas public. The discovery of the actual Chicxulub crater in 1990 saw the possible causes of the dinosaur end, as well as the 1994 views of the Walloping Jupiter of the shoemaker Comet Levy 9, and convinced Congress to take the murderer's asteroid threat seriously. In 1998, Congress directed NASA to detect and catalog it within ten years at least 90% of what is called Earth Objects (NEOs) that are closer than a kilometre wide.
NASA and its partners took time to achieve that goal, so in 2005, Congress directed to identify at least 90% of all NEOS 140 meters. Over 18,000 NEOs have been identified, but there may be about 40 people each week, and over 1 million people there. That mission continues.
Recent fears about the asteroid known as the 2024 YR4 have made this killer asteroid search, which makes the course a bit less academic. (When Neos is discovered, it is initially given a name that reflects the year of the ID, then given a letter and number indicating the order in which the year begins with AA.
The 2024 YR4 was discovered on December 27th last year at a Chilean station, a NASA-funded asteroid detection program by Atlas, an asteroid detection program with telescopes from around the world. Its estimated diameter is 130-300 feet, so it is not the world's ender, but if it collides with the Earth, it can cause serious localized damage. Early calculations suggested that there was a 3.1% chance of hitting the planet on December 22, 2032, which was a concern.
3.1% may not look that risky – it's roughly the same possibility as flipping the coin five times to get all heads or all tails – but it was three times more expensive than that of other large known astides. This was a big deal for Skywatchers. There they got caught up in action and pulled data from observatory run by NASA, the European Space Agency, and the Japanese Aerospace Exploration Agency.
Asteroids, like all objects in the universe, follow clear and largely predictable orbits, providing an opportunity to stop at least one planetary disaster. The impact of an asteroid occurs when the object's orbit and Earth's orbit intersect. Get plenty of data, do mathematics, and scientists can get an incredibly accurate picture of whether Earth will suffer from space fender benders decades away.
Once new measurements were made and mathematics were completed, the chances of YR4 hitting the Earth began to decrease, eventually dropping to just 0.004%. Such a crisis was averted. However, YR4 does not erase any city, but provided valuable tests for planetary defense science.
So, what happens if it is confirmed that a large asteroid is in the impact path of its collision course with Earth? Asteroid detection systems prevail over asteroid defense systems, but at least in theory there are several options.
Project Icarus already understood this in the 1960s. There is no need to destroy asteroids to protect the Earth. You need to give them a little nudge. Treat them like eight balls on a pool table and knock them out. This analogy cue ball is known as the “motor impact factor.” This is a spacecraft that impacts an asteroid with enough force to change its orbit.
I know this works. On September 26, 2022, NASA's Double Planet Redirect Test (DART) collided with a small asteroid-shaped model, more than 7 million miles from Earth. The darts were successful, reducing the Dimorphos trajectory by 32 minutes.
The dirt was not perfect. The collision also shows some of the unintended consequences of unleashing a herd of rocks and breaking something into a space rock of about 14,760 mph. As science writer Robin Andrews pointed out in X, dirt was at best evidence of principle and not something that could be used on asteroids like YR4 when necessary.
Of course, much larger asteroids that actually threaten the entire planet require much more power and technology we don't have yet. (No, like Bruce Willis, you can't send oil excavators with nuclear bombs yet. Armageddon. )
But even so. The brilliant space scientists, international collaborations, and yes, even the acts of Congress, our species are approaching being able to forever protect themselves from the natural existential risks that have erased the dominant species of our planet's past. If that's not good news, I don't know what.
This version of the story originally appeared in Good News Newsletter. Sign up here!
