Nasa is close to finding life on Mars but the world is not ready for the “revolutionary” implications of the discovery, the space agency’s chief scientist has said.

Dr Jim Green has warned that two rovers from Nasa and the European Space Agency (ESA) could find evidence of life within months of arriving on Mars in March 2021.

The ExoMars Rover, which has been dubbed “Rosalind” in memory of British chemist Rosalind Franklin, will search for extra-terrestrial life by drilling 6.5 feet down into Mars’ core to take samples.

Those samples will then be crushed up and examined for organic matter in a mobile laboratory.

Dr Green compared the potential discovery to when the astronomer Nicolaus Copernicus stated that the Earth revolves around the Sun in the 16th century.

Best Nasa pictures of the month Show all 10 1 /10 Best Nasa pictures of the month Best Nasa pictures of the month The eye of Hurricane Dorian as captured by Nasa astronaut Nick Hague from onboard the International Space Station (ISS) on 3 September Nasa/EPA Best Nasa pictures of the month The River Nile and its delta captured at night from the ISS on 2 September Nasa Best Nasa pictures of the month The galaxy Messier 81, located in the northern constellation of Ursa Major, as seen by Nasa's Spitzer Space Telescope Nasa/JPL-Caltech Best Nasa pictures of the month The flight path Soyuz MS-15 spacecraft is seen in this long exposure photograph as it launches from the Baikonur Cosmodrome in Kazakhstan on 25 September Nasa/Bill Ingalls Best Nasa pictures of the month Danielson Crater, an impact crater in the Arabia region of Mars, as captured by Nasa's Mars Reconnaissance Orbiter spacecraft Nasa/JPL-Caltech Best Nasa pictures of the month A team rehearses landing and crew extraction from Boeing's CST-100 Starliner, which will be used to carry humans to the International Space Station at the White Sands Missile Range outside Las Cruces, New Mexico Nasa/Bill Ingalls Best Nasa pictures of the month Bound for the International Space Station, the Soyuz MS-15 spacecraft launches from the Baikonur Cosmodrome in Kazakhstan on 25 September Nasa/Bill Ingalls Best Nasa pictures of the month Hurricane Dorian as seen from the ISS on 2 September Nasa Best Nasa pictures of the month A string of tropical cyclones streams across Earth's northern hemisphere in this picture taken from the ISS on 4 September Nasa Best Nasa pictures of the month The city of New York as seen from the ISS on 11 September Nasa

“It will start a whole new line of thinking. I don’t think we’re prepared for the results,” he told The Sunday Telegraph. “I’ve been worried about that because I think we’re close to finding it and making some announcements.”

Nasa’s rover Mars 2020 will drill into rock formations on the planet before sending test-tubes of rock samples back to Earth – the first time material from Mars will have been brought onto this planet.

Dr Green added that the discovery of life on Mars will give scientists a new set of questions to explore.

“What happens next is a whole new set of scientific questions. Is that life like us? How are we related?” he said. “Can life move from planet-to-planet or do we have a spark and just the right environment and that spark generates life – like us or do not like us – based on the chemical environment that it is in?”

Recent research has shown that planets which were previously thought to be uninhabitable may have once had suitable conditions for life.

Earlier this year, scientists discovered that there may be a vast and active system of water running underneath the surface of Mars.

A study released this month also claimed that Venus may have been habitable for 2 to 3 billion years before its atmosphere became incredibly dense and hot about 700 million years ago.

Recent research suggests that civilisations could exist on other planets, according to Dr Green.

“There is no reason to think that there isn’t civilisations elsewhere, because we are finding exoplanets [planets outside the solar system] all over the place,” he said.

His comments came less than 24 hours before technology entrepreneur Elon Musk unveiled a SpaceX spacecraft designed to carry crew and cargo to Mars or other planets in the solar system before returning to Earth.

Mr Musk said the company’s Starship was essential for the viability of space travel by introducing a spacecraft that can be reused.