Suppose you are an astronaut who has just landed on Mars. What would it take to survive? A short list: Water, food, shelter - and oxygen.
Oxygen is found in the air we breathe here on Earth and is produced by plants and certain species of bacteria.
But oxygen is not the only gas in the Earth's atmosphere. It is not even what dominates. In fact, only 21% of our air is made up of oxygen. Almost all the rest is nitrogen - about 78%.
Now you may be wondering: If there is more nitrogen in the air, why do we breathe oxygen?
Technically, when we inhale we take in what is in the atmosphere. But your body only uses oxygen. Eliminates all the rest by exhalation.
The wind on Mars
The atmosphere of Mars is delicate. Its volume is only 1% of the Earth's atmosphere. To put it another way, there is 99% less air on Mars than on Earth.
This is partly because Mars is about half the size of Earth. Its gravity is not strong enough to prevent atmospheric gases from escaping into space.
The predominant gas in this delicate atmosphere is carbon dioxide. For us on Earth, it is a poisonous gas in very high concentrations. Fortunately, it is much less than 1% of our atmosphere. On Mars, however, carbon dioxide is at 96% of the air!
Mars, meanwhile, has almost no oxygen. is only one tenth of 1% of the air, not at all enough for humans to survive.
If you were trying to breathe in surface του Άρη χωρίς διαστημική στολή που σας παρέχει οξυγόνο – θα πεθαίνατε σε μια στιγμή. Θα πνιγόσασταν και λόγω της χαμηλής ατμοσφαιρικής pressures, your blood would boil.
Life without oxygen
So far, researchers have found no evidence of life on Mars. But the search has just begun. Robotic detectors have barely scratched the surface of Mars.
Without a doubt, Mars is an extreme environment. And it's not just the air. There is very little water on the surface of the planet. Temperatures are incredibly cold - at night, they reach below -73 degrees Celsius.
There are many organisms on Earth that survive in extreme environments. Life has been found on the ice of Antarctica, on the ocean floor and miles below the Earth's surface. Many of these places have extremely hot or low temperatures, with almost no water and little to no oxygen.
Even if life on Mars no longer existed, it may have existed billions of years ago, when the planet had a denser atmosphere, more oxygen, higher temperatures, and significant amounts of water on its surface.
That's one of the goals of his mission Perseverance rover of NASA. To look for signs of ancient life on Mars. This is why the Perseverance searches the Martian rocks for fossils of organisms that once lived or some trace of primitive life, such as microbes.
Oxygen Do it yourself
Among the seven instruments in the Perseverance rover is the MOXIE, an incredible device that removes carbon dioxide from the Martian atmosphere and converts it to oxygen.
If MOXIE works the way scientists hope, future astronauts they won't just make their own oxygen. they could also use it as an ingredient in the rocket fuel they will need to fly back to Earth. But even with "native" oxygen, astronauts will still need a spacesuit.
NASA is currently working on new technologies needed to send humans to Mars. This could happen in the next decade, perhaps sometime in the late 2030s.