The story begins off the coast of what is now Yucatán, where a mountain of rock arrived at roughly twenty kilometers a second.
The impact threw dust and soot into the atmosphere. Sunlight dimmed, temperatures fell, and the effects moved through ecosystems over the years that followed.
The difference now is observation. The sky is no longer unmeasured.
We now have physical measurements of these asteroids, enough to predict where they will go and how much of a threat they pose to Earth.
The inner solar system is mostly empty space, organized by motion. The Sun sits at the center, the planets circle it, and Earth holds its own narrow orbit.
So before we count any threats, we get our bearings here. Then the planets step back and we drop in close to Earth.
The glowing point is a single asteroid. Its tail traces how it moves relative to Earth, and the rings mark distance in lunar distances. One LD is the gap between Earth and the Moon.
A red dot is flagged potentially hazardous, and that word sounds alarming. But it is really a bookkeeping label. The object is big enough, and its orbit runs close enough to Earth's, that we keep measuring it.
Every dot is a near-Earth asteroid, and each rides its own measured orbit. It looks crowded, but this is not chaos. It is simply the full population we can track and compare at once.
The cutoff is bureaucratic, not apocalyptic. An object has to be bigger than about 140 m, and its orbit has to pass within 0.05 AU of Earth's.
But the label only starts the watching. It means keep an eye on this one, not that it's headed for us.
Across 13,691 projected approaches this century, the typical pass misses by 79 lunar distances. That sounds close, but it sits far beyond the Moon's orbit.
So the chart spreads those misses into a distribution. Sweep across the bars to see what each distance band looks like around Earth.
A dinosaur-scale impact needs two things at once. It takes a very large object and a path that actually reaches Earth.
But plot size against closest pass and the corner that would matter, big and near, stays empty. The giants keep their distance, and the close ones stay small.
Plenty of these asteroids are big enough to wreck a region if they hit, and a smaller group could go global.
But the last threshold isn't about size at all. It's an actual collision course, and none of the 2,000 asteroids here crosses it.
The row on the right is a scale check. A few near-Earth asteroids dwarf the Chicxulub impactor, and others come closer or are simply better studied.
But you have to read those facts separately. Size, closeness, and an Earth-crossing path are three different ingredients, and real danger needs all three at once.
When Apophis turned up in 2004, astronomers had only a short arc of observations. The early orbit carried enough uncertainty that a 2029 impact couldn't be ruled out yet.
But that uncertainty was temporary. More observations tightened the orbit, and the risk fell as the measurements sharpened.
Better data erased the 2029 risk, and later tracking ruled out any impact for at least a century.
But it will still make a genuinely close pass. On 13 April 2029, Apophis sweeps about 38,000 km from Earth, nearer than many satellites, so watch the distance fall and then open back up.
The controls come back now, so you can search by name, isolate the monitored set, or lock onto a single asteroid and follow it through the century.
The pattern should read clearly by now. There are plenty of close approaches, but every measured path in this sample slides past Earth, not through it.
No, not from anything in this catalog. Every one of the 2,000 near-Earth asteroids tracked here clears Earth on every projected pass this century, and the typical one misses by 79 lunar distances. The largest asteroids stay distant, and the few that come close stay small. Even Apophis, the object that once carried a real impact scare, now reads as an ordinary flyby. None of that promises that nothing will ever strike us. But a catalog was never meant to make that promise. Its job is to measure what is out there, and that measurement is what turned a fear into a number.
Our team, the Pickle Farmers, started from NASA's Near-Earth Asteroids dataset and built a pipeline that cleans the 2,000-object catalog, derives each asteroid's time-propagation elements, and flattens roughly 42,000 Earth close-approach events. On top of that sits a Three.js orbital theater that propagates every asteroid across a century using Kepler's equation. We wrapped the whole explanation in a scrollytelling format where that 3-D scene stays on stage the entire time. The narrative scrolls alongside it and drives it, flying the camera to named asteroids, toggling the hazardous set, and surfacing linked D3 charts at each beat. Select any asteroid and it gets graded live against the impact and extinction thresholds.
The hard part was the coupling between the scrolling narrative and the live scene. We had to propagate thousands of orbits every frame without dropping below 60 fps, choreograph camera moves from a system-wide view down to a single close pass, and keep the clock, the chart overlays, and the on-screen labels in sync as the reader scrolls. Keeping a reader oriented through those moving, scroll-driven shots was the central design problem, and it took a lot of iteration to land.