Imagine that you are living in a house, and you have been living in the same house in the same locality since the time you were born. Your parents lived in this very house before you were born and their parents (your grandparents) lived in this very house before them.

So, there is naturally a lot of sentimental value attached to this house.

Back when your grandparents were living here, the house was brand new, the neighbourhood was new, you could walk out of the house onto roads lined with big trees, and a beautiful river was just a short walk away. There were hardly any vehicles in the area, so there was no pollution. The electricity and water supply were in abundance and the local supermarkets stored fresh produce from local farmers that were both tasty and healthy.

But today, for you, things have changed. A lot more people have come into the neighbourhood because life there was so good. This has driven up prices of everything from the house itself to the restaurants and transport options around. There are cars everywhere you look which is both noisy and polluting. The big trees that had lined the roads have been cut down to make room for more houses for all the new people that have come into the neighbourhood. The quality of electricity and water supply have degraded, requiring you to buy Tesla batteries and install solar panels to ensure uninterrupted power supply throughout the day. The river has nearly dried up as all the new people in the neighbourhood have been consuming the water from the river.

The place is no longer the paradise it once was.

Yet, there is a huge amount of sentimental value that is preventing you from selling the house and moving onto a different neighbourhood.

So, yielding to that sentimental value, you convince yourself that the only plausible alternative is to fix your neighbourhood by moving to clean energy resources, sustainable fishing and farming, reducing pollution through emissions and reducing dependence on the fast drying up river so that it can replenish itself. You go about trying to convince everyone in the neighbourhood to buy into your ideas and behave accordingly.

While doing all this, you still think it is unfair to stop letting new people come into your neighbourhood. You know that your grandparents invited their cousins and friends to come join them in the neighbourhood back in the day, and feel like a hypocrite to impose rules on the people living there today to not bring in their cousins and relatives. Which they continue to bring in in droves, driving up the pressure on the resources that sustain your neighbourhood.

Is that the approach you would take? Or would you start exploring other neighbourhoods in the city (or even a different city) where the situation is still like how it was for your grandparents, or at least has the possibility of being that way if you worked towards it? Will you yield to the practical solution or hold onto the sentimental attachment and live in this neighbourhood until you die, trying to make what little changes you can?

I would start looking for any other neighbourhoods that I can move to where the situation isn't the same. And so would Elon Musk.

Your neighbourhood that I describes is planet Earth today. And that other neighbourhood being looked into by a handful of people like Elon Musk is Mars.

We don't have a duty to prevent (reverse?) global warming or to reduce pollution or to stop using fossil fuels or to move to sustainable farming practices. We don't have a duty to preserve planet Earth as it once was. We don't have a duty to protect millions of species of flora and fauna from going extinct. We don't have a duty to treat every human as equal and protect their rights.

It is just in our best interests to do so for the propagation of our species, and of life itself.

And while this is one plan to achieve that, establishing a colony and thus life on Mars, is another equally viable plan. It might even be the plan with the higher probability of achieving the end goal among the two.

And that is why Mars matters.