In my last post, I wrote about K2-18b, the amazing exoplanet where NASA’s James Webb Space Telescope may have found hints of life. At the end, I asked a tough question: “What is the point in finding new planets to possibly destroy alongside our own?” After diving deeper into the science, I’ve realized the answer is more interesting than I thought.
First, the search for planets like K2-18b isn’t really about finding a backup Earth. NASA scientists, including Dr. Sara Seager from MIT, have explained that studying distant worlds helps us understand how planets form, evolve, and sustain atmospheres. That knowledge actually teaches us more about our own planet and how to protect it. So, exploration isn’t the same thing as escape.
Another important fact is that even if K2-18b turned out to have life, moving there is basically impossible with current technology. It’s 124 light-years away, which sounds small until you realize that with our fastest spacecraft, Voyager 1, it would take over two million years to reach it! Even if we invented futuristic propulsion like fusion rockets or light sails, scientists estimate it would still take centuries. This shows the goal of studying K2-18b isn’t to “go there” at all—it’s to learn from it.
And the learning goes both ways. The same techniques James Webb uses to study K2-18b’s atmosphere are also used to track greenhouse gases here on Earth. NASA reported in 2024 that exoplanet research has actually improved climate models for our own planet. Comparing K2-18b’s hydrogen-rich atmosphere with Earth’s helps scientists understand how atmospheres change over time, which is crucial for predicting and fighting climate change.
There’s also the bigger question: what if we actually find life? If K2-18b really does have organisms producing gases like dimethyl sulfide, it would be the first confirmed life beyond Earth. That would be one of the greatest discoveries in human history. But scientists like Carl Sagan have pointed out that such a discovery would also remind us how fragile life really is. As he famously said, “The Earth is the only home we’ve ever known. There is nowhere else, at least in the near future, to which our species could migrate.” Finding life out there might make us even more protective of life down here.
Some people worry that spending money on exoplanet research means less is being done for Earth, but that isn’t really the case. NASA spends far more on Earth science missions than on exoplanets. Satellites like Sentinel and Landsat are tracking deforestation, greenhouse gases, and melting ice caps in real time. Studying K2-18b is not taking resources away from saving our own planet; both missions are happening side by side.
So what’s the point in all of this? It turns out that searching for new planets isn’t about finding somewhere else to ruin. It’s about understanding how rare and valuable life is, using that knowledge to protect Earth, and answering one of humanity’s oldest questions: Are we alone in the universe? Ironically, the more we search for life “out there,” the more science tells us we need to take care of the life we already have right here.