Nasa's Perseverance rover has landed on Mars - here's how long it took to get there

Nasa’s Mars Perseverance rover has safely landed on the red planet and sent back images, marking an “amazing accomplishment”, the space agency announced. Its mission is to search for signs of ancient life, and explore and collect samples for future return to Earth from diverse environments on Mars. After the rover entered the Martian atmosphere there were “seven minutes of terror” as it made its way to the surface. It took more than 11 minutes for news of the safe landing to reach Earth. But just how long does it take to cross the blackness of the Solar System to reach the Red Planet from our own? How far away is Mars? The distance between Earth and Mars - while relatively small given the unimaginable scope of the universe - is huge. The differing orbits of the planets around the Sun mean that the Red Planet’s distance from Earth can alter dramatically, but even at its closest, Mars still sits roughly 36 million miles away. How long did Perseverance take to get there? Perseverance's took seven months. The Perseverance rover lifted off from Cape Canaveral Air Force Station on 30 July at 7:50 am EDT (12:50pm BST) beginning its voyage to the Red Planet. It made its way across the vastness of space towards Mars, aiming for a landing in the planet's Jezero Crater, an area which scientists believe could be rich in preserved organic molecules and other signs of microbial life. What is the purpose of the mission? Now landed, the Perseverance rover will search for signs of ancient microbial life, characterise the planet's geology and climate, collect carefully selected and documented rock and sediment samples for return to Earth, and pave the way for human exploration. Perseverance will also ferry a separate technology experiment to the surface of Mars, a helicopter named Ingenuity - the first aircraft to fly in a controlled way on another planet. Loaded with scientific instruments, advanced computational capabilities for landing and other new systems, Perseverance is also the largest, heaviest robotic Mars rover Nasa has built. Where did it land? The first couple of images from the rover showed a flat, rocky surface, and were met with a second round of cheers as mission control celebrated the achievement. More images, videos and sounds from the landing are expected to start arriving from the rover over the weekend. Early indications suggest Perseverance had landed on a relatively flat surface, and not too far from some sand dunes which will have to be navigated in order to reach the delta. Images from Nasa showed the rover had landed in tiny safe space, surrounded by red areas that would have been very difficult to land in. Showing slides highlighting areas of various colours, Nasa’s Entry, Descent and Landing lead official Allen Chen, said: “I was just worried about what would kill us on landing. “Red is generally bad, and you can see that the system managed to find a nice blue spot in the midst of all that red – all that death that’s out there for us. So we found a parking lot.” How long would it take a human crew to get to Mars? One of Perseverance’s mission tasks is to pave the way for human exploration. But just how long would a manned mission to the planet take? The answer: nearly two years. Though that does include the return trip. With humanity's current rocket technology, it would take at least nine months to reach the planet itself. Once there, the crew would need to wait for a minimum of three months for the planets to realign in a way which would make the return leg economically viable for factors such as fuel consumption. Then it's another nine months back, for a total of 21 months. Aside from the time, the length of such a manned mission brings about a number of logistical challenges. Nearly two years' worth of food, water, clothes, and medical supplies would be needed for the crew, not to mention the scientific equipment required for any experiments. Then there's the issue of fuel: it's estimated that a crew of six would need three million pounds (nearly 1.4 million kg) of supplies. A version of this article originally appeared on our sister title, The Scotsman