Now that there is strong evidence of flowing water on Mars, many are wondering what that really means.
On Monday, NASA made the announcement that there was strong evidence that water — a brine composed of perchlorate, a type of salt — flowed down slopes and ebbed and flowed during the summer and winter months.
WATCH: Flowing water on Mars
Water on Mars is a big deal, but it’s not something new.
Scientists have known for years about ice at the planet’s poles. And more recently it was confirmed that dirt on Mars contained water. So why is this so important?
Because it’s flowing. But still, that doesn’t mean that we can expect to see Earth-like oases.
“It’s not as if it’s puddling or forming lakes,” said Paul Delaney, senior lecturer and professor of physics and astronomy at York University.
Astronomers and planetary scientists believe that billions of years ago water was abundant on the surface of Mars, making it possible that life once thrived there. However, until now there had been no concrete evidence of liquid water on the surface, nor any life on what we once thought to be a barren planet.
NASA has always followed the idea of “follow the water” when it comes to searching for life on Mars and really, the entire solar system. That’s because as far as we know, life on Earth needs water to survive.
“Follow the water, and we might find life,” Delaney said.
Life on Mars
And life always seems to find a way (we only need look to extremophiles: life that survives in what we think to be harsh conditions such as with no sunlight or in highly acidic conditions).
Though we’ve known that there is water ice on Mars for some time, we’re still not certain in what form it exists. Scientists believe that it lies beneath the surface as ice. However, this new discovery shows that there is moving water which could indicate underground aquifers.
“The fact that water can exist — albeit briny and briefly — tells us water is very near the surface,” Delaney said.
Liquid water might also mean that there is microbial life beneath the surface.
It’s believed that the surface of Mars might be too harsh for life to exist abundantly. That’s because the planet lacks a protective magnetic field, like the one that envelops Earth. But with liquid water — and possibly a aquifer as a supply — small life might be a possibility.
Easier for human colonization?
This discovery of flowing water doesn’t necessarily bolster the argument that it will make colonization on Mars easier for humans. It’s not like there will be flowing freshwater streams that we can use as a source of water. Instead, we will turn to the ice that we’ve known about for a long time.
The challenge is getting it.
We know that ice exists to a latitude of 70 degrees on Mars. That’s not an ideal place to set up a colony as, just like here on Earth, there are periods when the sun doesn’t shine, making it difficult to utilize the solar energy we will need for power.
However, if — with more follow-up — it is discovered that Mars possesses aquifers, that could change things. Underground water would indeed mean that we could settle at lower latitudes with less need to cart water from the poles to our location. We’d be able to get it from the site.
Are we a danger to life on Mars?
Knowing that there is a possibility of microbial life, there is the danger that we could contaminate it with our own form of microbes.
NASA goes to great lengths to ensure that its spacecraft are microbe-free. It builds them in clean rooms. But even this measure won’t keep microbes out all the time: In 2013 NASA confirmed the discovery of two microbes in two separate and distant clean rooms.
Does this mean humans should be wary of visiting far-off worlds?
“We first asked that question when we went to the moon,” Delaney said.
However, the difference is, the chance that any life ever existed on the moon is almost slim to none, at least with current knowledge. But Mars could have once possessed life and could still.
Delaney said that if we’re truly afraid of bringing Earth life to other planets, we will be relegated to exist here on Earth, never to venture from home.
“Astrobiologically speaking, we are novices,” he said. “We just need to be cautious. We need to be thoughtful and careful.”