In late 2015, NASA’s Mars Reconnaissance Orbiter (MRO) provided the strongest evidence yet that liquid water is flowing intermittently on Mars.
We’ve known for a while about dark streaks on the surface of the red planet, but this is the first confirmation that the markings were made by flowing water.
This discovery is the first evidence of its kind, and the first step in confirming life can exist on Mars.
According to Jim Green, NASA’s Director of Planetary Science, the next step is to find the source of the water.
“This is tremendously exciting. We haven’t been able to answer the question “does life exist beyond Earth?” But following water is a critical element of that,” he said.
Image: NASA/JPL/University Of Arizona
While the possibility of microbial lifeforms on Mars is exciting on its own, the presence of water also opens up other possibilities – like the potential for humans to live on the red planet.
“These observations are giving us a much better view that Mars has resources that are useful to future travellers. I think we will send humans in the near future to Mars... to be able to live on the surface, the resources are there,” says John Grunsfeld, astronaut and associate administrator at NASA’s Science Mission Directorate.
NASA went as far as to say it thinks it will send humans in the near future to Mars. The space agency has previously floated the 2030s as their target for putting humans on the red planet.
So, what do we need to achieve before life on Mars becomes a reality?
Any flight to Mars will require a journey of around 2.5 years – six months to get there, a 1.5 year wait for Mars and Earth to be back in the right positions to return and then six months to get back to earth.
That means we need to be sure humans can withstand more than a year in Mars’ low gravity atmosphere which is just one-third of the gravity on Earth.
A spacecraft that could safely land humans on Mars would probably need to weigh up to 60 tonnes.
On landing, the Mars Curiosity Rover weighed only 900 kilograms. A bigger craft would be infinitely more difficult to both build and land.
With only 38 percent of Earth's gravity and an atmosphere high in carbon dioxide, exploring our new Martian home would come with major challenges.
Our current spacesuits, used on the moon and on-board the International Space Station, are too heavy for exploring the red planet’s surface so NASA would need to develop newer, lighter models.
Transporting humans across the surface of Mars would also require new vehicles. Something like the golf buggy-sized Curiosity Rover would be inept at taking humans across the planet at 100 kilometres an hour.
Once we get to Mars, we’ll need to fuel our lungs, our stomachs and our vehicles.
NASA has recently grown lettuce on the International Space Station, but growing enough food on Mars to sustain a large population becomes a much bigger challenge.
An option for making fuel is to split water from Mars’ surface into hydrogen and oxygen, which could then be used for fuel for vehicles, water for drinking and oxygen to breathe.