Somebody should do the math and share it with the general population on moving to some other planet as the solution to saving humanity.

I don’t think there is sufficient energy to get very many humans off of planet Earth to populate a new planet. Yes some new technology can be developed and change the calculation but nothing practical is on the horizon yet.

Remember that a Saturn V rocket that launched three astronauts burned 15,000 pounds of fuel PER SECOND on the initial ascent.

Randall Monroe, in his book What If, estimates it will take 4 gigajoules per person to escape Earth’s gravitational attraction. Four gigajoules is about a megawatt-hour. Four gigajoules times 7 billon people is about 8 peta-watt-hours or about 5 percent of the world’s energy use per year.

But remember that rockets must also lift their own fuel. To launch a 65 kilogram human would take about 30 gallons of gasoline which weights 90 kilograms. So now you need to lift 155 kilograms so we would need more fuel. The good news is the fuel would burn and get lighter on the way up otherwise this would be an “infinite loop” calculation … more fuel to carry more fuel.

The net calculation, according to Randall, says a one ton craft needs between 20 to 50 tons of fuel. Launching all 7 billion people would take tens of trillions of tons of fuel.

And we have not even included the food and water needed to survive the long trip to any other planet.

So … we could send a small group of humans to restart the human race but only a fraction of the inhabitants of the Earth could leave.

Thank you Randall Monroe for this less than intuitive insight. By the way he was a real rocket scientist with NASA.

Hummm … the next question is who gets to go?