ExoMars ready to resume search for alien life

To boldly go: Scientists say a recent crash landing taught them valuable lessons. © ESA

European ministers will decide this week whether to invest £350m in a project to put a rover on Mars. ExoMars will search for life on the red planet — so what if life is actually discovered?

There is no life as we know it on the surface of Mars. The atmosphere is too harsh to support it. But around two metres underground, there may be microbial activity.

This is why engineers working for the European Space Agency (ESA) want £345m to upgrade the ExoMars probe. If European ministers approve the funding this week, the rover could be drilling beneath the surface early in 2021.

The project suffered a setback recently, when a small probe crashed while trying to make a demonstration landing on the red planet. But another probe which was sent to look for methane has just made a successful entry into the atmosphere. And Dr David Parker, who works for the ESA, calls the mission ‘scientifically compelling’.

‘There is no other mission planned to go below the surface of Mars,’ he says.

The search for life on the red planet has occupied astronomers for centuries; in the early 1900s, Percival Lowell was convinced that the dark channels on Mars’s surface were canals made by an intelligent society. However, so far, scientists have been disappointed.

So what would happen if life is finally found? For most people, the discovery would be a fascinating story — but once the excitement died down their day-to-day lives would not necessarily change much.

In contrast, for scientists, it could change everything. Biologists, in particular, would suddenly be introduced to a much broader range of resources to study.

An alien microbe would provide ‘enough material to revolutionise biotechnology’ explains the science writer Ben Miller. That is not just a ‘minor curiosity’, but a huge step for medical research that would eventually benefit us all.

And then there are the philosophical implications. If Earth is not alone in hosting life, humans must reconsider their place in the universe. Religions may have to adapt their teachings. And eventually, humanity will need to decide how to relate to its extraterrestrial neighbours.

Infinity and beyond

Some scientists are wary of the impact that humans can have on foreign species — just look at the mass extinctions caused by the anthropocene. We must learn from these mistakes and leave alien life alone. As the astronomer Carl Sagan wrote in 1980: ‘If there is life on Mars, I believe we should do nothing… Mars then belongs to the Martians, even if the Martians are only microbes.’

But Robert Zubrin, president of the Mars Society, disagrees. It would be a ‘crime against science’ if we knew that alien life existed and we did not study it. Besides, why should we go so far out of our way to protect bacteria on Mars, when we do not even do the same on Earth? The benefits of interacting with alien life would far outweigh the risks.

You Decide

  1. If ExoMars discovers microbes on Mars, what should scientists do next?
  2. Would the discovery of alien life change how you thought about life on Earth?


  1. It is 2018. The second ExoMars mission has drilled through the planet’s surface and discovered life. Write down the three most important questions that humanity must answer.
  2. Imagine you are communicating with an intelligent alien species for the first time, billions of miles away. What do you want them to know about Earth? Write, draw, or record the very first transmission you would send.

Some People Say...

“Until we solve Earth’s problems, we have no business meddling with other planets.”

What do you think?

Q & A

If it wouldn’t change my life, why does it matter?
Finding life on Mars may not change your life in the short term — no rioting in the streets, no sudden Doctor Who-style invasion. But it in the long-term, it would be a significant turning point in humanity’s story. If there is life on other planets, we would have a lot of questions to ask about what we want our own future in the universe to look like.
How likely is it?
The answer depends on who you ask. Many scientists are convinced that alien life is out there — even if there is no life on Mars, astronomers have found billions of Earth-like planets that could support it. But others are less sure. If aliens are out there, why haven’t we been contacted? No one knows exactly how life began on Earth; perhaps it was a one-in-a-billion fluke.

Word Watch

The Martian atmosphere has too much radiation, which has damaged the planet’s surface, to allow life to survive there.
An intergovernmental organisation, separate from the EU but about 20% funded by it.
A joint mission between the ESA and Russian space programme, Roscosmos. The probe was assembled by British scientists.
A chemical compound, one atom of carbon and four of hydrogen, found in the natural gas which is often used as fuel, and emitted by living things — including microbes, humans, and especially cows. Scientists suggest meteorites exposed to ultraviolet radiation on Mars’s surface could give off much of the methane; but they do not rule out ‘a possible biological origin’ for some of it.
Percival Lowell
Published his theories in books including Mars and its Canals (1906). His ideas about intelligent societies were partly due to a mistranslation of Giovanni Schiaparelli’s observations of ‘canali’ (’channels’, not ‘canals’) on Mars in 1877.
A geological era in which the presence and actions of humans has had the most influence on the Earth.

PDF Download

Please click on "Print view" at the top of the page to see a print friendly version of the article.