By: Andy Blanchard RASC (Hamilton)
For: Curious Minds
What is Apophis?
Picture a giant space rock about the size of three football fields zooming through the solar system at speeds faster than your Wi-Fi drops during a storm. That’s 99942 Apophis, an asteroid that’s been the center of attention because, in 2029, it’s going to pass closer to Earth than some of our satellites. Sound scary? It’s not. Let’s explore why Apophis is more of a cosmic tourist than a threat.
How Close is “Close”?
On April 13, 2029, Apophis will pass Earth at about 32,000 kilometers (20,000 miles). To put that in perspective, that’s closer than the satellites that beam your favorite TV shows, yet still far enough that we’re completely safe. Think of it like a bird flying over a soccer field while you’re standing on the sidelines—you see it, you notice it, but it’s not even close to hitting you.
Why All the Buzz?
Back in 2004, when scientists first spotted Apophis, they thought there was a 2.7% chance it could hit Earth in 2029. Those odds were enough to grab everyone’s attention. But after years of better observations and improved math, they’ve ruled out any chance of impact. Today, we know Apophis will miss us completely in 2029—and for at least the next 100 years.
Why Do People Still Worry?
Let’s face it—asteroids have a bad reputation. Hollywood loves making movies about “the big one” wiping out Earth, and the idea of an asteroid passing so close stirs up questions. Here are a few common worries:
- What if the math is wrong? It’s not. Scientists worldwide have double-checked Apophis’s trajectory with some of the best tools and data available.
- What if Apophis’s orbit changes? Good question! Asteroids don’t always stick to the same path forever (we’ll explain why in a bit).
- Why does this sound like a plot from a movie? Because Hollywood loves drama. Reality? Not so much.
Why Could an Asteroid’s Orbit Change?
Asteroids like Apophis don’t fly through space on perfectly straight tracks. Their paths can shift slightly over time due to a few key factors:
- Earth’s Gravity: When Apophis zips by in 2029, our planet’s gravity will pull on it. This won’t drag it toward Earth, but it might nudge its orbit a little—like flicking a marble just enough to change its direction.
- The Yarkovsky Effect: Imagine Apophis lounging in the Sun, soaking up rays. As it heats up, it radiates energy back into space. That tiny push from heat can, over decades, slightly alter its orbit. (It’s like a cosmic version of one side of your pizza box getting soggy and tilting everything off balance.)
- Collisions with Space Dust or Other Rocks: Space is big, but it’s not empty. A collision with even a small rock could tweak Apophis’s orbit. This is rare, but it’s something scientists consider.
- Solar Winds: The Sun constantly blasts particles into space. While they’re too weak to shove Apophis around much, they can cause minuscule adjustments over long periods.
What If Apophis Hit Earth?
Let’s pretend the math is somehow wrong, and Apophis decides to pull a surprise move (spoiler: it won’t). What would happen?
- If it hit land:
It would leave a crater about 2-4 kilometers wide and flatten everything for miles. Think forests, buildings, and maybe a few unlucky squirrels. The explosion would release 1,200 megatons of energy—about 24 times more than the largest bomb ever detonated. - If it hit water:
A splash this big would cause mega-tsunamis, with waves hundreds of meters high crashing into coastal cities. Surf’s up… but in the worst way possible.
But don’t panic—this is purely hypothetical. Apophis’s current trajectory keeps it far, far away from us.
Why We’re Safe
Here’s why you can relax:
- Scientists Have It Covered: Teams worldwide track Apophis with radar, telescopes, and math. They’ve double-checked their work so often that the chances of a collision are officially zero.
- We’ve Got a Plan (Just in Case): Missions like NASA’s DART are testing ways to nudge asteroids off course if one ever poses a real threat.
- The Odds Aren’t Just in Our Favor—they’re Absolute: Apophis’s 2029 path is so well-mapped, even amateur astronomers can confirm it won’t hit.
Why Apophis is Cool, Not Scary
Instead of worrying, let’s focus on how amazing this flyby will be:
- It’s a Science Party: Scientists will use Apophis’s close pass to study how Earth’s gravity affects asteroids.
- It’s a Skywatcher’s Dream: Apophis will be visible to the naked eye from some parts of the world, moving across the sky like a fast star.
- It’s Rare: Close encounters like this don’t happen often, and they give us a front-row seat to cosmic events.
The Final Word
Apophis isn’t a doomsday asteroid—it’s a cosmic celebrity making a cameo near Earth. So, don’t buy into the hype or worry about Hollywood scenarios. Instead, grab your telescope (or join the club for a viewing night), and let’s marvel at the universe doing its thing. It’s big, it’s bold, and it’s definitely not a threat.