To paraphrase a common refrain from astrophysicist Neil deGrasse Tyson, the big problem with the dinosaurs was that they didn’t have a space program.
With the exception of those of us who are misguided religious fundamentalists, we all know that a huge asteroid impact some 66 million years ago caused the extinction of the dinosaurs. A few select species survived the catastrophe to become birds. But it was a mass extinction event: About half of all plants and animals disappeared from Earth.
Considering that the dinosaurs survived more than 150 million years before a large space rock wiped them out, asteroid impacts may certainly seem like a distant concern for modern Earth dwellers. However, throughout our planet’s long history, there have been many large asteroid impacts, and there will surely be more if we do nothing about it.
Scientists, using the best metric system for studying asteroid impacts, found that a space rock five kilometers in diameter (which is just over three miles in diameter to Americans) can be expected to slam into Earth in average every 31.25 million to 62.5 million years. . A five kilometer asteroid hitting anywhere on Earth would be very bad news for humans.
True planet killers are thankfully much rarer. Asteroids 10 kilometers or more in diameter, like the one that killed the dinosaurs, only hit Earth, on average, every 250 million to 500 million years or so.
Remember, these are averages. If another dinosaur era were to hit us tomorrow after only 66 million years, nature would simply be arriving a little earlier than anticipated. It might make up for waiting another billion years after that to pulverize the squids or whoever ended up inhabiting Earth after us.
Until this week, no one was really sure if there was anything we could do if we found a large asteroid approaching Earth. Now, thanks to the US space program, we know.
A few weeks ago, NASA hit a large asteroid with a refrigerator-sized space probe traveling at 14,000 miles per hour. This asteroid, known as Dimorphos, was about the size of a football stadium (not a planet killer, but capable of destroying a city). Dimorphos was orbiting a much larger asteroid (none of the asteroids posed a threat to Earth, this being a proof of concept). The idea behind this Double Asteroid Redirection Test, or DART for short, was to see if giving an asteroid a little “nudge” from a great distance using nothing more than kinetic energy might be enough to redirect its path.
Since the overall effects of NASA’s DART mission were intended to be subtle, it was not possible to measure whether the test was successful on impact. Now, however, the initial data is available and it appears that DART was even more successful than scientists had dared to hope.
The DART probe exceeded expectations by altering the path of Dimorphos. This was the first time in history that humans altered the trajectory of a celestial body.
Space exploration has already provided us with enormous social benefits. If you love camera phones, laptops, and GPS, along with many other things we all now rely on every day, thank space exploration.
But all of that pales in comparison to saving everyone and everything from total destruction. Even putting aside the possibility of deflecting an asteroid the size of the one that killed the dinosaurs, getting a single city killer like Dimorphos out of Earth’s path would more than justify the $330 million cost of the DART mission (not to mention any other useful technologies that the mission will lead to that we cannot yet fathom).
It is difficult to overstate the importance of the success of the DART mission. And what an elegant solution: no nukes flying over a giant tube of rocket fuel that might just explode in our atmosphere, no Bruce Willis type having to (spoiler!) sacrifice himself for the good of humanity, just a a little diligence, a lot of math, and getting your old Frigidaire up to 14,000 miles per hour.
Now all we have to do is avoid destroying ourselves in some other way while we wait for the next asteroid.
Jonathan Wolf is a civil litigator and author of Your debt-free JD (affiliate link). He has taught legal writing, written for a wide variety of publications, and has made both his business and his pleasure financially and scientifically literate. Any opinion he expresses is probably pure gold, but nonetheless it is his alone and should not be attributed to any organization with which he is affiliated. He wouldn’t want to share the credit anyway. He can be contacted at [email protected].