The discovery, based on analysis of photographs from the Mars Reconnaissance Orbiter satellite, increases the likelihood that the fourth planet from the sun could support life, either currently or in the past.
NASA scientists made the announcement at a widely publicized and broadcast news briefing at agency headquarters in Washington, D.C.
NASA had announced that the news briefing was scheduled to discuss a “major science finding,” and allowed the public to watch on its website and ask questions of scientists via the Twitter social media website.
Monday’s briefing coincided with the release of a new research paper stating that seasonal streaks seen on Mars were the result of salty water flowing down slopes on the planet surface.
Three of the paper’s co-authors spoke at the news briefing,according to Cable News Network (CNN).
While researchers have long known that Mars had frozen water at its poles and recently discovered tiny puddles that formed on the surface at night, today’s announcement marked the first time flowing water was discovered on the planet, which had been thought to be cold and barren.
The seasonal streaks, called recurring slope lineae — are the result of briny water periodically flowing across the planet’s surface.
The streaks were first noticed by the paper’s lead author, Lujendra Ojha of the University of Arizona, in 2011, CNN said.
Ojha and several of his colleagues, including Mars orbiter chief Alfred McEwen and NASA researcher Mary Beth Wilhelm, also spoke at the briefing.
But the paper did not determine where the water was coming from but suggested that it was melting subsurface ice, pulled from the atmosphere by salts in Martian soil or coming from a subsurface aquifer, CNN said.
“Unraveling the story of water on Mars is important to unlocking its past climate history, which will help us understand the evolution of all planets, including our own,” NASA states on its website.
Other top NASA experts at the briefing were Jim Green, the agency’s director of planetary science, and Michael Meyer, lead scientist for the Mars Exploration Program.
NASA also has two mechanical rovers operating on Mars, named Spirit and Opportunity, although the Spirit rover stopped communicating with Earth in 2010.
Opportunity continues to travel on the planet’s surface and transmit data, however.
