We regret to inform you Earth will not be destroyed by an asteroid within 1,000 years
Never mind, there's always nuclear war and climate catastrophe
War, genocide, TikTok – if it could all end today, some of us would die with a smile on our face knowing there was little about humanity worth preserving.
However, we have bad news for the misanthropes out there: the cosmic mote of dirt we call home is safe from planet-killing asteroids for the next thousand years or so.
This is the conclusion drawn by astroboffin Oscar Fuentes-Muñoz from the University of Colorado, Boulder, and team in a paper [PDF] titled "The hazardous km-sized NEOs [near-Earth objects] of the next thousands of years" that has been accepted for publication in The Astronomical Journal.
Rogue asteroids are serious business – just ask the dinosaurs. Oh wait, you can't because they're all dead. Why? Asteroid. At least that's what many scientists think, and there's plenty of geographical evidence for it. The 180km-wide, 20km-deep Chicxulub crater on the coast of Mexico is believed to have been caused by a 10km space rock 66 million years ago that snuffed out most prehistoric life and left Earth choking on dust and debris for years.
The intervening period has been pretty quiet and the surviving critters that could shelter from the fallout have gone on to do quite well for themselves. All the same, at the request of US Congress in 1998, NASA keeps a wary eye on the sky and has almost completely cataloged every NEO larger than a kilometer across – a civilization-ending event if any were to hit Earth – of which there are about 1,000. The space agency estimates that one of these strike every few million years.
Because gravity and orbits are predictable in the short term, scientists can reliably track asteroid paths about 100 years into the future, but Fuentes-Muñoz and colleagues wanted to peer further.
- Alien rock causes cosmic disturbance in New Jersey home
- Eta Aquariid meteor shower peaks this weekend, and will be one for the ages
- Space dust that regularly hits Earth could contain proof of alien life
- Queen's shooting star was actually meteor, not SpaceX junk
As co-author Davide Farnocchia, from NASA's Center for Near Earth Object Studies, told MIT Technology review, the key was a "less computationally intense approach to take a peek at a longer time interval." By pinning down "the fraction of the orbit that can bring the object close to Earth," he said the team could model impact risks much further out than has been possible before.
"In general, asteroid impacts capable of causing significant damage to Earth are extremely unlikely," he said. "Just in case, we are doing our due diligence."
The study found that the closest we'd get to asteroid annihilation within the next millennium would be at the hands of 1994 PC1, a rocky object 1km wide, which has a 0.00151 percent chance of passing inside the orbit of the Moon. It's a Hail Mary, but also a 10 times higher risk than any other asteroid in the neighborhood.
"It's still not likely that it's going to collide," said Fuentes-Muñoz. "But it will be a very good scientific opportunity, because it's going to be a huge asteroid that's very close to us." So at least our descendants have that to look forward to – if we haven't already obliterated ourselves over some dumb human-caused stuff.
It's all a far cry from the space pebble that trashed a New Jersey bedroom the other week, but NASA is still trying to document smaller asteroids more than 140m across, which have the potential to flatten cities – a task about 40 percent complete, Fuentes-Muñoz said. "But it depends on how many there are, which is really uncertain. We're not sure. But there's hope that new surveys of the sky will give us a much higher completeness rate."
Oh well. It's not like we need any help with our death drive. Thanks to the atomic bomb, climate change, war in Europe, and economic ruin, humanity hasn't been this close for a while. ®