Reflections

 Was reading through recent evening conversations with Copilot. Here's an odd

one, goes well with cookies!!

Copilot:

Could one run a fighter jet on Mars; it has a very thin atmosphere...

Running a traditional fighter jet on Mars would be virtually impossible with current technology — and here's why:

🛩️ Fighter Jets Need Air — Mars Doesn’t Offer Much

Fighter jets rely on air-breathing engines (like turbojets or turbofans), which compress atmospheric oxygen to burn fuel. Mars’ atmosphere is:

~100 times thinner than Earth’s

Composed of ~95% carbon dioxide, not oxygen

Lacking the density needed for aerodynamic lift and engine combustion

So, a jet engine simply wouldn’t work — there’s not enough oxygen to burn fuel, and not enough air to generate lift with conventional wings.

🚀 What Could Work on Mars?

To fly on Mars, you'd need radically different tech:

Rocket propulsion: Rockets carry their own oxidizer, so they don’t rely on atmospheric oxygen. NASA’s Ingenuity helicopter hitched a ride with Perseverance and proved powered flight is possible — but it’s tiny and uses electric rotors, not combustion.

Electric aircraft: Solar-powered drones or aircraft with large rotors and ultra-lightweight frames could fly in Mars’ thin air, but they’d be slow and delicate — not exactly fighter jets.

Nuclear thermal propulsion: A speculative option for future Mars vehicles, but still in early research stages.

✈️ Could You Modify a Jet?

Even with extreme modifications, a fighter jet would face huge hurdles:

No oxygen → no combustion

Low pressure → no lift

Cold temperatures → materials and electronics would need redesign

Dust storms → could damage intakes and sensors

You’d essentially need to replace the engine, redesign the wings, and rethink the mission profile — at which point, it’s no longer a fighter jet.

If you're imagining a sci-fi scenario — say, a Mars-based interceptor or drone — we could brainstorm what that might look like. Want to go there?

Is the Earth's Atmosphere becoming less oxygen rich?

Yes — Earth's atmosphere is experiencing a slow but measurable decline in oxygen levels, though it's not an immediate crisis for human life. Here's a breakdown:

🌍 How Much Oxygen Is in the Atmosphere?

Earth's atmosphere is about 21% oxygen.

This level has remained relatively stable for human history, but long-term data shows a gradual decrease.

📉 What’s Causing the Decline?

Fossil fuel combustion: Burning coal, oil, and gas consumes oxygen and releases carbon dioxide.

Deforestation: Fewer trees means less oxygen produced via photosynthesis.

Ocean deoxygenation: Warmer waters hold less oxygen, and nutrient pollution creates “dead zones” where oxygen is depleted.

Population growth: More respiration and industrial activity means more oxygen consumption.

A Princeton study found a 0.7% drop in atmospheric oxygen over the past 800,000 years, and a 0.1% drop in the last century due to human activity.

🧪 Is This Dangerous?

For now, the drop is not enough to affect human breathing.

But it’s a concern for marine ecosystems, where oxygen loss is more rapid — about 2% since the 1950s, leading to expanding dead zones.

Long-term projections suggest that if current trends continue, oxygen levels could become problematic for some species and ecosystems.

🔮 What About the Far Future?

NASA scientists predict that in about a billion years, Earth’s atmosphere could shift dramatically — becoming methane-rich and oxygen-poor, similar to its pre-Great Oxidation Event state. This would make the planet uninhabitable for most life as we know it3.

Would you like to explore how oxygen levels are monitored or how this ties into climate change models?

Is Nasa's prediction based on current trends, or something else?

NASA’s prediction about Earth eventually losing its oxygen-rich atmosphere is not based on current human-driven trends like fossil fuel use or deforestation. Instead, it stems from long-term planetary evolution models driven by astrophysical and geochemical processes.

Here’s what’s behind it:

🔭 NASA’s Billion-Year Forecast: Driven by the Sun

NASA scientists, in collaboration with researchers from Japan’s Toho University, modeled how Earth’s atmosphere will evolve as the Sun gradually becomes brighter over the next billion years. Key drivers include:

Increased solar radiation: As the Sun ages, it emits more energy, warming Earth.

Carbonate-silicate cycle slowdown: This geochemical cycle regulates CO₂ levels. As it slows, CO₂ drops, affecting photosynthesis.

Photosynthesis collapse: With less CO₂, plants can’t produce oxygen efficiently.

Methane-rich shift: Eventually, Earth’s atmosphere could resemble its pre-oxygen state — dominated by methane and devoid of breathable oxygen2.

This transition is predicted to occur hundreds of millions to a billion years from now, not due to human activity but due to stellar and planetary aging.

🧬 Not a Climate Change Forecast

NASA’s model is not a warning about current oxygen decline from pollution or deforestation. Those are real concerns, but they’re short-term and localized compared to this billion-year-scale transformation.

So while Earth’s oxygen levels are slowly declining due to human activity, the NASA prediction is about a fundamental shift in planetary habitability — a natural end to Earth’s oxygen era.

Would you like to explore how this ties into the search for habitable exoplanets or Earth’s geological history?