NASA announced this morning that the major Mars discovery they teased about in previous days is in fact flowing water. It has long been thought that water had existed somewhere on Mars and there are large amounts of frozen water in the polar caps but this is the first concrete evidence ever found of liquid water.
“Today, we’re revolutionizing our understanding of the planet,” said Jim Green, NASA’s director of planetary science “Mars is not the dry, arid planet that we thought of in the past – under certain circumstances, liquid water has been found on Mars.”
The Mars Reconnaissance Orbiter (MRO) was used to make the discovery. It has been used to map changes in the Martian terrain over the past few years. A GIF showing changes on Mars due to water flows can be seen here, courtesy of NASA:
But visual evidence wasn’t enough. In order to confirm that water was the cause of these changes, scientists used the spectrometer aboard the MRO to look at infrared light emitted from the Martian slopes when the streaks appeared. They found evidence of hydrated minerals proving that water is causing the dark streaks as it flows downwards.
The water flows discovered are only in liquid form during the Martian summer, when temperatures in the area are above -10°F (-23°C). Normally this is too cold for liquid water to exist but the water flows are Mars are very high in salt content and have been referred to as ‘briny.’ Salty water actually has a much lower freezing point so it can stay liquid at much colder temperatures. The salts present in the water in these flows are chlorates and perchlorates. The salt content of the water is much higher than that in the Earth’s oceans.
This discovery has refueled the idea that there may be life on Mars. On the Earth, wherever we find water, we find life. The same may be true about Mars. While most organisms don’t do well in very salty water there is a group of extremophiles called halophiles that thrive in these conditions. A Martian version of these could exist in these water flows.
Unfortunately there’s no mission currently planned to explore the areas where water is flowing at the moment and sending completely sterile rovers that can scale the side of a steep slope to Mars is difficult and expensive.
It is still a mystery where all of the water is coming from. There may be a hidden reservoir that it is draining from or some cycle bringing water to the top of mountains. More research is needed before we can understand the mechanisms that allow water to flow 0n Mars.
The water on Mars could actually turn out to be useful for manned missions to Mars in the future. It could be purified for drinking water or used as fuel as hydrogen is a common fuel source used in rockets.
The study was published by several scientists including Lujendra Ojha, who first put forth the idea that the dark streaks seen on Mars were caused by water flows, Mary Beth Wilhelm, of the Georgia Institute of Technology and Alfred McEwan of the University of Arizona.