Will This Killer Asteroid Hit Earth in 2029? Scientists Say They'll Know for Sure by 2027

Rocky Future

Don't panic, but the odds of a massive asteroid named Apophis smashing into Earth just got just a smidge higher.

Originally projected to harmlessly fly past us in a close approach, a new study published in The Planetary Science Journal suggests that there's actually a fraction of a chance that the 1,100-foot hunk of rock could collide with our planet after all, in the far off year of 2029.

The odds are less than one in a billion, fortunately, and would require the unfolding of a cosmic pool trick-shot to happen, but going from no chance to slim chance is still unnerving when we're talking about a mini-apocalypse on our hands.

Fortunately, Apophis — ominously named after the ancient Egyptian deity of Chaos — isn't considered big enough to wipe out human civilization outright, but it's certainly big enough to obliterate an entire city. But the real killer, most likely, will be the wait: we can't rule out the possibility of an impact until 2027, according to the study.

Bump Bump

First, we should note that Apophis, which astronomers have been observing since its discovery in 2004, isn't currently on a warpath for Earth. The study's sole author Paul Wiegert, an astronomer at Canada's Western University, found that it's still projected to fly past our planet at a distance of several Earth radii on April 13, 2029. Very close — it'll come between us and the Moon — but no cigar.

What's new, however, is the possibility that the trajectory could change if Apophis collides into another object along the way, like a smaller asteroid. According to Wiegert, almost none of the calculations on its trajectory so far have accounted for this happening since we haven't found any other asteroids that could cross paths with it. Even a study that did investigate this, which Wiegert published in March, found that the odds of this happening were "zero."

He's now recanting that. According to his latest findings, Wiegert says that Apophis could bump into tiny asteroids too small for us to see yet. If one of these wayward objects were just eleven feet across in size, that would be hefty enough to nudge it on a collision course with our planet in 2029.

And if it struck an object even just two feet across, it could also put it on a collision course — but at a later date, perhaps in 2036 or 2068.

Wait and See

Still, these impacts, even if they occur, would have to be perfectly placed to turn Apophis into an Earth-seeking missile. The odds, Wiegert calculated, is less than one in two billion. Even the odds of an impact occurring and causing a significant deflection — that doesn't necessarily put Apophis on a collision course — are less than one in one million.

Because Apophis is currently in the daytime sky, observing it with telescopes won't be possible until 2027. Even with a clear view, however, confirming that it was struck by something will be tricky, since by then most of the visible aftereffects will have dissipated, Wiegert wrote.

Still, he's optimistic that simple, direct observations of the asteroid that year will be enough to safely put the impact risk to rest — or perhaps to confirm our impending doom. Until then, it's out of our hands.

More on asteroids: Debris From When NASA Smashed Asteroid Appears to Be Headed Back Toward Earth