We are still at 97.7% chance of a miss from this asteroid
Impact probability increased from 1.2% to 2.3%, but this reflects measurement uncertainty rather than increased danger. Newly discovered asteroids have high orbital uncertainty; the asteroid's position along its orbital plane remains unclear until more data accumulates.
- Impact probability rose from 1.2% to 2.3% (one in 83 to one in 43)
- Asteroid 2024 YR4 is approximately 196 feet wide
- Discovered in December 2024; last visible in 2016
- Uncertainty should resolve by 2028 when asteroid returns to view
Odds of asteroid 2024 YR4 hitting Earth in 2032 doubled to 1-in-43, but experts emphasize the 97.7% miss probability means no cause for concern as uncertainty is expected to decrease with more observations.
An asteroid discovered last December has climbed to the top of the world's most-watched near-Earth object list, and the numbers tell a story that sounds alarming until you understand what the numbers actually mean. The odds that 2024 YR4 will strike Earth in 2032 have risen to one in forty-three. But asteroid hunter David Rankin, who first recovered images of the space rock in archival survey data, wants to be clear: this is not a reason to lose sleep.
When Space.com first reported on 2024 YR4 in December, the impact probability stood at one in eighty-three. The jump to one in forty-three looks like a near-doubling of risk. But the math tells a different story. One in eighty-three translates to a 1.2 percent chance of impact—which means a 98.8 percent chance of a miss. The new one-in-forty-three figure represents 2.3 percent odds of a strike. That leaves 97.7 percent odds of the asteroid sailing safely past. The probability of missing Earth has not halved; it has barely budged. "People should absolutely not worry about this yet," Rankin said.
What makes this story worth understanding is why the odds keep shifting at all. When astronomers discover a new asteroid, they know some things about its orbit with high confidence and other things barely at all. They can map the plane in space that the asteroid travels on with reasonable precision. What they cannot pin down, at least not yet, is exactly where along that plane the asteroid will be when it reaches Earth's neighborhood. This uncertainty manifests as what Rankin calls a "line of variation"—a confined band of possible positions. For 2024 YR4, that line of variation passes uncomfortably close to Earth. As new observations come in and the uncertainty shifts, sometimes the odds of impact tick upward, even though the most likely outcome remains a clean miss.
Rankin offered an analogy to explain how tiny measurement errors can produce outsized orbital shifts. Imagine holding a stick a few feet long and moving your hand a fraction of an inch. You barely notice the movement at the far end. Now imagine that stick stretches millions of miles into space. That same fraction-of-an-inch movement at your hand causes dramatic swings at the distant end. The "fraction of an inch" in this case is the minuscule timing errors and positional uncertainties that arise when telescopes photograph the asteroid. No measurement is perfect. So astronomers plot all the possible orbits consistent with the observations they have, producing a distribution of possibilities. As more data arrives, that distribution changes shape and position.
The asteroid itself, estimated at 196 feet wide, is currently moving away from Earth, making it hard to observe. Rankin and colleagues will continue tracking it through February 2025 using eight-meter telescopes at the Catalina Sky Survey. But the real breakthrough could come from archival hunting. Teams of scientists worldwide are combing through data from 2016, the last time 2024 YR4 was visible to Earth-based observers. If they find it in those old images, they can either confirm or rule out the 2032 impact scenario outright. If not, Rankin expects the uncertainty to drop dramatically once the asteroid swings back into view after orbiting the sun again—or by 2028 at the latest, when it should become visible once more. The story of 2024 YR4 is not one of mounting danger but of mounting knowledge, and that knowledge is coming.
Citas Notables
People should absolutely not worry about this yet— David Rankin, asteroid hunter
We still expect that to start falling at some point— David Rankin, on the impact odds
La Conversación del Hearth Otra perspectiva de la historia
Why does the probability go up if we're not in more danger?
Because we're not measuring danger—we're measuring uncertainty. We know the asteroid could be in a range of positions along its orbital path. That range includes Earth's location. As we refine our measurements, sometimes that range shifts in a way that makes Earth's position slightly more central to the possibilities. But the most likely outcome is still a miss.
So the odds could go down just as easily?
Absolutely. Rankin expected this to happen. He's been saying from the start that the odds will fall again once we have more data. Right now we're in a window of high uncertainty, and that window is working against us statistically.
What would actually settle this?
Finding the asteroid in archival images from 2016 would do it immediately. Or waiting until 2028 when it comes back into view. Either way, we'll have enough observations to nail down its position along that orbital plane instead of just guessing.
How wide is the asteroid?
About 196 feet across. Not enormous, but substantial enough that if it hit a populated area, it would cause real damage. That's part of why people are paying attention.
Is Rankin worried?
Not at all. He's been tracking this since discovery in December. He knew the odds would fluctuate. He's confident the uncertainty will resolve in our favor, probably well before 2032.
What's the worst-case scenario if we don't find it in old data?
We wait until 2028 when it's visible again, gather more observations, and narrow down the possibilities. By then we'll have a much clearer picture. But even then, the odds of impact are likely to be far lower than they are now.