The Short Answer
Getting to Mars usually takes about seven months. Most robotic missions have made the crossing in somewhere between six and nine months, depending on exactly when they launched and the path they took. There’s no single fixed number, because Mars is a moving target and the distance between our two worlds is always changing.
If the Moon is a weekend trip, Mars is a proper expedition. It’s the difference between popping to the next town and sailing across an ocean. And the reason it takes so long isn’t just that Mars is far away, it’s that spacecraft don’t fly there in a straight line at all. Let’s unpack why the Red Planet sits seven months out, and why that number keeps shifting.
Mars Is Never the Same Distance Away
The first thing to understand is that there’s no such thing as “the” distance to Mars. Both Earth and Mars are racing around the Sun on their own orbits, at their own speeds, so the gap between us is constantly opening and closing.
At their absolute closest, in theory, the two planets can come within about 54.6 million kilometres of each other, though in practice a good close approach is more like 56 to 100 million kilometres. At their farthest, when they sit on opposite sides of the Sun, they can be over 400 million kilometres apart. That’s a massive range, and it’s why you can’t just pick one travel time and call it settled. For a fuller breakdown of the Red Planet’s orbit and where it sits, our guide to Mars, its size, distance, and orbit digs into the details.
You Don’t Fly in a Straight Line
Here’s the part that trips people up. Even at Mars’s closest approach, spacecraft don’t aim straight at it. Instead, they follow a long, curving path around the Sun called a transfer orbit.
Think of it like throwing a ball to someone who’s jogging. You don’t aim at where they are, you aim at where they’re going to be. Mission planners fire a spacecraft into a wide arc that loops halfway around the Sun, timed so that the spacecraft and Mars arrive at the same point at the same moment. This route is far longer than a straight shot, but it’s enormously more fuel-efficient, and fuel is the single biggest constraint in spaceflight. Trading a shorter distance for a huge fuel saving is a bargain worth making.
What Real Missions Have Taken
The seven-month figure isn’t a guess, it’s the lived experience of the spacecraft we’ve actually sent. NASA’s Perseverance rover launched on July 30, 2020, and touched down in Jezero Crater on February 18, 2021, a journey of just under seven months. The Curiosity rover took a little longer, around eight and a half months. Going back further, the various orbiters and landers have generally clustered in that same six-to-nine-month window.
The reason they don’t vary more wildly is that every one of them used a similar fuel-saving transfer orbit. Launch a bit faster and you can shave off some time, but it costs a lot more fuel, so mission designers rarely bother unless there’s a good reason.
Why You Can’t Just Launch Whenever You Like
There’s another catch that shapes the whole thing. You can’t set off for Mars on any random Tuesday. Because both planets are moving, there’s only a narrow window when Earth and Mars line up in the right positions for that efficient transfer orbit to work.
These launch windows open roughly once every 26 months, which is why Mars missions tend to bunch together, several nations launching within weeks of each other and then a two-year gap before the next opportunity. Miss the window and you’re waiting more than two years for the next one. It’s a big part of why a future crewed Mars mission would likely involve a long stay on the surface, since the crew would have to wait for the planets to realign before heading home, stretching a round trip out to two or three years.
Could We Ever Go Faster?
In principle, yes. The seven-month figure is tied to today’s chemical rockets and their fuel limits. Engineers are actively developing more advanced propulsion, including nuclear thermal and nuclear electric engines, that could one day cut the journey dramatically, with some concepts aiming to shorten a crewed trip to a matter of weeks rather than months. That would make Mars far more practical for human explorers, since less time in transit means less exposure to radiation and less strain on the crew.
For now, though, seven months is the honest answer for the vast majority of missions. It’s worth remembering just how close that makes Mars in cosmic terms. Even radio signals, travelling at the speed of light, take anywhere from about 3 to 22 minutes to cross the gap, which is why rovers have to drive themselves rather than wait for joystick commands from Earth. If you’re curious how you’d stack up on the Red Planet itself, our weight on other planets calculator is a fun way to feel the difference, and our beginner’s guide to the planets puts Mars in context with the rest of the neighbourhood. NASA’s Mars page is a great place to keep exploring.
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