It was yesterday morning when I first heard the news that the James Webb telescope had found signs of life on a planet outside our solar system. Ngl, I was fascinated. Here it goes:

“K2-18b, located 124 light-years from Earth, could be a Hycean world: a potentially habitable planet entirely covered in liquid water with a hydrogen-rich atmosphere,” said lead study author Nikku Madhusudhan, professor of astrophysics and exoplanetary science at the University of Cambridge’s Institute of Astronomy. “Earlier theoretical work had predicted that high levels of sulfur-based gases like DMS and DMDS are possible on Hycean worlds. And now we’ve observed it, in line with what was predicted. Given everything we know about this planet, a Hycean world with an ocean that is teeming with life is the scenario that best fits the data we have.” — CNN

“The team sidestepped this challenge by analyzing light from K2-18 b’s parent star as it passed through the exoplanet’s atmosphere. K2-18 b is a transiting exoplanet, meaning that we can detect a drop in brightness as it passes across the face of its host star. This is how the exoplanet was first discovered in 2015 with NASA’s K2 mission. This means that during transits a tiny fraction of starlight will pass through the exoplanet’s atmosphere before reaching telescopes like Webb. The starlight’s passage through the exoplanet atmosphere leaves traces that astronomers can piece together to determine the gases of the exoplanet’s atmosphere.” — NASA

Read the full articles here:

• Scientists detect signature of life on a distant planet, study suggests
• Webb Discovers Methane, Carbon Dioxide in Atmosphere of K2-18 b

As said in the articles, this is the strongest evidence humans have ever had for life on other planets. If this is true, it completely shifts our perspective. It means life in our galaxy is not as rare as we thought it would be—it might even be inevitable.

I’ve seen Floppy Disks, Smart Phones, Quantum Computers, Artificial Intelligence and now Aliens. What an era to live in. What a time to be alive.

“The oldest and strongest emotion of mankind is fear. And the oldest and strongest kind of fear is the fear of the unknown.”

First things first, let’s ask this question: What are we actually looking for?

When we stare into the void, we need some kind of framework to make us search better. We need to identify the universal rules that intelligent species follow. To do that, we compare them to ourselves, looking at the energy we consume and the work that we have done.

The Kardashev Scale

This framework ranks hypothetical civilizations based on their energy consumption and technological reach. It scales into different categories:

• Type 1: Is able to harness and use the available energy of their entire home planet.
• Type 2: Is able to harness and use the available energy of their star and planetary system (like building a Dyson sphere to capture starlight).
• Type 3: Is able to use and control the available energy of their entire galaxy.
• Type 4: Is able to use the available energy of multiple galaxies, mastering the visible universe.

Here is the catch: If there were any Type 3 or higher civilizations, we would have noticed their massive energy signatures by now. After all, a civilization that spans an entire galaxy couldn’t hide, and they certainly couldn’t have missed us. So this means any type of life outside our solar system, including whatever might be in the oceans of K2-18b, can only be Type 1 or Type 2.

But if the universe is this old, and life is this common, where are they?

“Two possibilities exist: Either we are alone in the universe or we are not. Both are equally terrifying.”

The Fermi Paradox

Enrico Fermi grasped a deeply unsettling mathematical reality: any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire galaxy within a few million years. On a cosmic timescale, that is practically overnight.

We look up at a sky filled with billions of stars, many much older than our own sun. Yet, we hear absolutely nothing. Just radio static. I mean, if we’re not alone, why is it so deafeningly quiet out there?

The Great Filter

One of the most well-known, and most dread-inducing, explanations for this paradox is that there is a “Great Filter.”

The theory suggests there might be a hard step in the evolution of life that’s extremely rare—either before intelligent life arises or still ahead of us. In other words: Some step between the start of life and becoming a galaxy-spanning civilization acts as an impossible wall. It is so hard to get past that almost no one makes it.

In our own civilization, this leads to two scenarios:

• 1. The Filter is Behind Us: If the hardest step is already behind us—like the initial leap from simple to complex life—then we might be incredibly lucky. We are the survivors. Maybe we’re one of the only ones to make it this far.
• 2. The Filter is Ahead of Us: If the hardest step is still ahead—like surviving our own technology, artificial intelligence, nuclear war, or climate collapse—then finding life on K2-18b is bad news. It would mean life starts easily but most civilizations self-destruct before reaching the stars, and we might too.

The Ultimate Unknown

So, what does this all mean for us? Finding signs of an ocean world 124 light-years away doesn’t just change science; it fundamentally changes how we view our place in the universe.

When I look up at the night sky now, I don’t just see the quiet mechanics of stars and distant planets. I see a massive, silent test. If something is out there on K2-18b, breathing in their hydrogen-rich atmosphere, I wonder if they look at their own sky and ask the exact same questions. Until we know the answer, we just have to keep training our models, building our future, and hoping the Great Filter is a hurdle humanity has already cleared.