It’s been 46 years since humans walked on the moon, or any other celestial body, and while Buzz Aldrin is still around punching out moon landing conspiracy theorists, a future where no one living human has been to space is fast approaching. Everyone remembers where they were for the moon landing, but it was 1969, and our attention spans are growing increasingly short. Since then, the world has advanced astronomically (pun intended), but we’ve never gone back to the Moon, let alone to another planet (or celestial dwarf). So why should we believe Mars has any chance of humanity reaching it anytime soon?

There’s convincing logic behind the push to reach Mars. For one, Mars is rich with metals ore that could be mined for profit. With the doomsday clock only two minutes away from midnight, having humans on Mars would ensure the survival of our species in the case of something especially dramatic happening. Plus, the technology we would discover while figuring out how to get there could save lives, like when an algorithm used to correct images taken by the Hubble Space Telescope ended up being better than traditional methods at finding breast cancer in x-rays. It could even provide a bit of relief with diplomacy between countries on earth because governments would have to band together to tackle the common challenges of spacefaring humanity. Think of China and America banding together to save Matt Damon in The Martian, or the vague and confusing international reconciliation in Arrival? We should send Matt Damon to Mars for real.

So why not the Moon? Despite providing some of the same benefits and being on average about 200 times closer, we’ll probably reach Mars first. For starters, Mars is bigger than the Moon, which means it has about two times as much gravity, or about 38% of what we experience on earth. There are negative effects of spending time without gravity: astronaut Scott Kelly’s chromosomes actually changed after his year in space, so the higher the gravity, the better. Unlike the Moon, Mars also has an atmosphere. Though not quite as strong as earth’s, it will make a huge difference when it comes to equalizing day and night temperatures, pressurizing habitats with outside air, and even protecting us from radiation. In fact, an unexpected solar flare in 1972 could have killed those last astronauts on the Moon if they had landed a mere month earlier. Pair that with the excitement of reaching an entirely new planet for the first time, and Mars is generally the peachier target.

But there are huge obstacles. Most glaringly, we don’t quite have a big enough rocket to make it to Mars. Rockets that launch astronauts nowadays technically only go into “Low Earth Orbit,” which doesn’t require nearly as much thrusting power. The cost to launch the strong enough Moon-era Saturn V rocket was $375 million in 1969 dollars, or roughly $2.6 billion nowadays. That’s a small fry for the entire Apollo mission cost, which would be about $20 billion per Moon landing today. Though we’d probably be able to cut that cost down a bit, the staggering price would likely be around that much when you consider the development of the rockets and Martian habitats.

Then, we’ve got to worry about keeping our pesky fragile bodies alive and healthy. We’d have to be strong and well enough after landing to start a colony after the about half a year period it’d take to reach Mars, which is a problem for us without gravity. We’d also have to plant sustainable food sources, which would be difficult on Mars’ rocky surface, so we’d likely have to bring enough of our own soil (or even be able to, err, make enough on our own during the trip). Lastly, there’s the radiation, which would be a long-term problem. Living on Mars would give you roughly the same amount of radiation as smoking a pack of cigarettes a day. Paired with a wild temperature variation even at the equator, we’ve got our work cut out for us when it comes to developing sturdy enough habitats and space suits for the CO2-ridden planet.

Thankfully, there’s hope. NASA plans on putting humans on Mars by the early 2030s, with space programs from Europe, Russia, Japan, India, and the United Arab Emirates all planning their own probes or unmanned landers during the 2020s. Since private companies aren’t held back by the same red tape that governments are, they can test and field Mars-worthy programs even faster. Unsurprisingly, the most hope comes from SpaceX, who plan on launching cargo missions to Mars in 2022, and manned missions by 2024. They plan to use the biggest rocket ever, which just so happens to be reusable to cut down costs. But SpaceX isn’t the only one with their eyes above the horizon – Lockheed Martin plan their own crewed Mars missions in the 2030s, and Blue Origin plans on a mid-2020s start date for mining resources off of the Moon.

So sure, we’ve slacked as a species to explore into the space around us, but thankfully, we’ve got the ball rolling when it comes to getting off the earth in the next coming years. It’s a bit overdue, but then we’ll finally have that moment to explain to our grandkids someday when they ask what we were doing when we found out that we had first stepped foot on Mars.