The sequence of images, taken by a powerful camera called HiRISE aboard NASA’s Mars Reconnaissance Orbiter, which has been orbiting the planet since 2006, shows "dark, finger-like" streaks in the Martian spring and summer, NASA reports.
These marks, 0.5 to 5 yards or meters wide, with lengths up to hundreds of yards long, fade in winter and return in the spring, suggesting the "flow of briny water," according to Alfred McEwen of the University of Arizona, Tucson.
"We haven't found any good way to explain what we’re seeing without water,” McEwan said during a press briefing last week, the Washington Post reports. According to the Post:
While the photos don’t prove the existence of water, they fit with evidence from other probes, such as the deep Martian canyons that only water could have carved.
Scientists say the water would be briny and salty, and have a freezing point much lower than water on Earth.
While frozen water has been detected near the surface of Mars, this would be the first evidence of liquid water on the planet. NASA reports:
Fresh-looking gullies suggest slope movements in geologically recent times, perhaps aided by water. Purported droplets of brine also appeared on struts of the Phoenix Mars Lander.
Previous space missions have also enabled scientists to obtain evidence pointing to biological microbial life outside of Earth, the International Business Times reports.
"NASA's Mars Exploration Program keeps bringing us closer to determining whether the Red Planet could harbor life in some form... And it reaffirms Mars as an important future destination for human exploration," NASA Administrator Charles Bolden told IB Times