Dark finger-like features on the surface of Mars indicate that there is water on Mars according to scientists Thursday.

The presence of water on Mars revives the theory that there could be alien life in the form of microbes on the Red Planet.

Images analyzed from NASA's Mars Reconnaissance Orbiter satellite show fingerlike streaks up to five yards wide that flow down slopes and crater walls on the planet during its late spring through summer, before they fade in the winter. At least one crater had around 1,000 streaks in it.

"This is the best evidence we have to date of a liquid water occurring today on Mars," said Philip Christensen, a geophysicist at Arizona State University, Tempe, according to a Reuters report.

Although the streaks are an indication of water on the surface of Mars it is not the same as finding water on Mars. The Mars orbiter has yet to find any water but that might be because the presence of water is too little to be detected by the orbiter's instruments.

"We have this circumstantial evidence for water flowing on Mars," Alfred S. McEwen of the University of Arizona, who is the principal investigator for the camera, said Thursday during a news conference. "We have no direct detection of water."

The scientists said the best explanation for the streaks was that they were caused by a flow of extremely salty water down the slopes. Highly salty water would not freeze in the planet's icy surface, which can have temperatures fall to 200 degrees below zero Fahrenheit, or evaporate in the planet's low air pressure. The scientists still have to explain why the streaks are dark or why they vanish each winter.

"It is more like a syrup, maybe, in how it flows," said McEwen who will also be the lead author of the report on their findings in the journal Science.

The presence of liquid water is exciting because running water is more likely to sustain life than ice. Microbes on Earth can live on pockets of salty water without seeing the surface and even if the water froze, organisms can go dormant and live near the surface until spring thaws the water again.

"This is very speculative, because we really have no idea whether or not there are extant organisms on Mars or whether there ever was life on Mars," Lisa M. Pratt, a biochemist at Indiana University said.

"If there were to be evolving organisms on Mars," she said, "I don't see any reason why they couldn't adapt to that kind of seasonally available, very brief access to resources. You bloom quickly, you do what you need to do, and you go dormant."