Now we can reach it with satellites and study the surface and atmosphere from Mars orbit and the surface. It only takes half a year to get there for our space probes. The atmosphere makes it possible to use parachutes on our landers. Delays in communication with Earth are substantial, but still allow the direct control of slow moving rovers. Because of all these nice characteristics we can send a lot of unmanned probes there.

And we do, because it is such an interesting place! There may have been, and may still be, life. Mars has water, an atmosphere we can make propellants from, plenty of room (same amount of land surface as the Earth)…….a planet with potential. With some courage and will, we can go there ourselves, live there and get home without extreme difficulty, thanks to the low gravity and thin, low drag atmosphere. With its vast quantities of hydrogen, oxygen, carbon and nitrogen, Mars has all the resources to support a technological society. We can make rocket propellant from its atmosphere. Some day we could colonise this red planet or even Terraform the place and shape it into a new Earth.

Where would we be without Mars? We would still have the Moon. We have already been there, and although there is still a lot to learn about it, it is basically a dry, dead place nowhere near as interesting as Mars.

Without Mars, our closest planetary neighbour would be Venus. With its crushingly high atmospheric surface pressure, lead-melting temperatures and thick CO2 atmosphere impermeable to sunlight, it is not a nice place for a holiday. It is most likely nothing ever lived there and nothing ever will. The pressure and temperature on Venus’ surface make for an extremely unfriendly environment for any robotic lander, let alone a manned spacecraft. Astronauts would not be able to walk around outside their craft, unless it is in a mechanical, tank-like titanium armour suit. Launching anybody or anything from its surface is even harder than from Earth, since Venus’ gravity is similar to that on our planet but it’s thick atmosphere creates enormous aerodynamical drag. To return a couple of astronauts from Venus would require a landing/return vehicle system larger than a Saturn V moonrocket! Venus has no practical use or colonisation future for us.

Next stop would be Mercury. A lot like the moon, but half the place is bathing in high solar radiation, and so are satellites in orbit around it. The heat from the sun fries spacecraft and the radiation zaps all onboard electronics unless you make a very specially designed system. Nobody wants to live there.

Without Mars, going outward, we would first have the giant gas planet Jupiter. It is very, very far away, so with our current and near-future propulsion technology humans can only reach it in huge colony ships. That would mean an enormous development effort far beyond anything we are currently able to do, requiring economy-wrecking amounts of money. And once we would get there, we would have only some small, dead moons to live on (some moons may harbour living oceans, but only under miles of ice). Even robotic spacecraft need a lot of time to get to Jupiter, meaning they need to be designed for a long life, which is why we do not send as many probes there as we do to Mars.

In case we would not have Mars, would there be a Venus Society, promoting manned Venus missions for lack of a better destination? I think not. A Mercury Society would even be less realistic, and a Jupiter Society would have a real hard time to convince anybody of the need and possibilities of human Jovian system colonisation.

Without Mars, we would need a leap in technology to survive on the Venus surface. Let alone do something useful there. We would need huge spaceships to get to Jupiter, and nobody would be able to return home for decades. Without Mars, there would be less incentive for us to go out and explore space and search for life out there. Mars is a planet we can reach now, and which can be settled by the people alive today. Without Mars, we would be doomed to remain stuck in Near Earth Orbit for the rest of this century. Thank Mars for Mars!