A bold plan to send a rover to Mars to collect rocks and then fly them back to Earth is taking shape as part of a joint project between Nasa and the European Space Agency (ESA).

The $7bn (£5.5bn) plan recently won support from authorities at Nasa, and this week the member states of the ESA are expected to give their backing to the plan too.

The complex trip, known as “Mars Sample Return”, will ultimately aim to bring back just half a kilogram of rocks to Earth, and will take more than a decade to achieve.

But scientists believe the colossal effort could be worth it as it will provide the best chance for in-depth analysis of rocks from certain parts of the planet, which could reveal whether there has ever been life on Mars.

The plan requires no fewer than three heavy rocket launches from Earth to achieve, as well as the first ever rocket take-off from another planet to launch the return journey.

Signs of ancient rivers on Mars revealed in new images Show all 13 1 /13 Signs of ancient rivers on Mars revealed in new images Signs of ancient rivers on Mars revealed in new images Perspective view of ancient river valley network on Mars These images taken by the European Space Agency’s Mars Express satellite show the marks that an ancient network of rivers have left on the planet’s surface. ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Ancient river valley network on Mars The valleys formed as they would on earth, with a strong flow of water carving its way through the landscape. What is less clear is where the water came from. Due to a lack of knowledge about the past climate of Mars, scientists can not tell whether it came from groundwater, precipitation, melting glaciers or something unheard of. ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Ancient river valley network on Mars This colour-coded topographic view shows the relative heights of the terrain in and around the network of dried-up valleys on Mars. Lower parts of the surface are shown in blues and purples, while higher altitudes show up in whites, yellows, and reds, as indicated on the scale to the top right. ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Ancient river valley network on Mars This image shows the landscape in and around a network of dried-up valleys on Mars. The region outlined by the bold white box indicates the area photographed by the Mars Express. NASA MGS MOLA Science Team/FU Berlin Signs of ancient rivers on Mars revealed in new images Eberswalde crater delta This dried-up ancient river delta once carried liquid water across the surface of Mars. The photographed area is 31 x 7.5km. Released on February 4 2019. ESA/Roscosmos/CaSSIS Signs of ancient rivers on Mars revealed in new images Eberswalde crater delta Eberswalde crater formed more than 3.7 billion years ago. The rim of the crater is only intact in the north-eastern part, the rest has been buried by debris from the nearby, more recently formed Holden crater. ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Eberswalde crater delta In the left of the image is the Holden crater, which is 140km across. To the right is the Eberswalde crater, which is 65km across. ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Korolev crater A perspective view of the Korolev crater, an 82-kilometre-across crater filled with ice found in the northern lowlands of Mars. Taken by the European Space Agency's Mars Express satellite. ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Korolev crater The Korolev crater, an 82-kilometre-across crater filled with ice found in the northern lowlands of Mars. Taken by the European Space Agency's Mars Express satellite. ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Korolev crater DisThis colour-coded topographic view shows the relative heights of the terrain in and around Korolev crater, an ice-filled crater in the northern lowlands of Mars. Lower parts of the surface are shown in blues and purples, while higher-altitude regions show up in whites, browns, and reds, as indicated on the scale to the top right. The crater’s thick deposit of ice can be seen at the centre of the frame. Released December 20 2018 ESA/DLR/FU Berlin Signs of ancient rivers on Mars revealed in new images Water buried under the south pole of Mars ESA’s Mars Express has used radar signals bounced through underground layers of ice to identify a pond of water buried below the surface. ESA/NASA/JPL/ASI/University of Rome Signs of ancient rivers on Mars revealed in new images Water buried under the south pole of Mars The brighttop line represents the icy surface of Mars in this region. The south polar layered deposits – layers of ice and dust – are seen to a depth of about 1.5 km. Below is a base layer that in some areas is brighter than the surface reflections, highlighted in blue, while in other places is rather diffuse. The details of the reflected signals from the base layer yield properties that correspond to liquid water. ESA/NASA/JPL/ASI/University of Rome Signs of ancient rivers on Mars revealed in new images Water buried under the south pole of Mars The 200km square study area is shown in the left image and the right image shows the radar footprints on the surface of Mars. ESA/NASA/JPL/ASI/University of Rome

“It’s as complicated as sending humans to the moon,” Brian Muirhead, lead MSR planner at Nasa’s Jet Propulsion Laboratory in California, told Science magazine.

In addition to using the rocks to search for clues of life having developed, geologists will also be able to learn more about the past environments of the red planet, which previously had a thicker atmosphere and liquid water on its surface, like Earth.

The whole project will piggyback on the existing Mars 2020 rover mission, set to launch in July.

The car-sized rover will touch down near Jezero Crater, a fossilised river delta in Mars’ northern hemisphere, thought to be 4 billion years old.

With its six wheels and suite of high-tech instruments, the rover will scour the surrounding rocks for evidence that alien microbes once lived on the red planet.

For the Mars Sample Return project, the rover will drill into the rock and then store cores in purpose-built tubes, which can then be stored within the craft, or cached for later retrieval.

In 2028, a second craft will be launched from Earth and land on Mars. This will then find the samples and load them into a rocket.

The rocket will be fired from the surface of Mars, up to a satellite in orbit around the planet. The craft will then return to Earth and the samples will be ejected and are forecast to crash down in the desert in the US state of Utah in 2031.