I'm really excited by this.

This is stuff you've built.

When I was researching and writing The Knowledge, I spoke to huge numbers of people.

I read huge amounts of stuff, but I also tried to put my money where my mouth was and did Minecraft projects from scratch of, if I was doing this for real, how would I go about it? We mentioned earlier about wanting to keep vehicles running.

It's not just about driving over to the next village, but machinery, as we just mentioned, removes the labor from our own muscles and our own sweat and toil.

Vehicles are very good for pulling a plow across a field, so it's much easier than having an animal or a person pulling a plow.

You want to keep machinery and transport working.

How much of our civilization or evolution, I don't know if I even said that correctly, but the evolution of a civilization, how much luck has been involved in it?

Why is it that carbon is so useful for life and silicon is something you consider, but it, it is probably less useful? Lewis.

Well, there's, there's more silicon on Earth than there is carbon.

And as Sara's just said, the, the substance of the planet, the, the crust, the rocks of the Earth are silicon.

So life on Earth didn't not choose silicon to build itself out of 'cause it was lacking silicon.

There's more silicon here than there is carbon.

It used carbon as alternative, alternative 'cause carbon is very good at building big, bendy, flexible molecules, molecules that can do things like become enzymes or, or run chemical reactions.

So as an astrobiologist, you, you try to walk this tightrope between not only looking for stuff or life that's just like us, because we acknowledge that alien life might be different, but also not just flinging ourselves off the cliff of a fantasy and trying to remain rooted as a scientist in what we know and what we can anticipate and what we can predict and what we can, we can test for.

Should we be talking to the aliens?

Lewis Dartnell is a professor of science communication at University of Westminster.

We know for a fact that billions of years ago, when we were first getting started here on Earth, Mars was a much more clement place, a more clement world in its own.

We know that it had a thick atmosphere to shield and blanket the planet, and it would have had organic molecules, the building blocks of all life as we know it.

So it stands to reason that maybe Mars had its own genesis, its own origin of life.