The search is on for evidence of organic compounds on the planet Mars. According to scientists at the US Space Agency, NASA's Phoenix lander has confirmed the presence of frozen water near the planet's surface. They expect more discoveries as the lander's robotic arm acquires more samples of Martian soil and ice. VOA's Paul Sisco reports.

White material, thought to be ice, is located only at the upper portion of the trench, indicating that it is not continuous throughout the excavated site

On the surface of the planet Mars, NASA's Phoenix lander began digging with its robot arm last month. The first images of a small trench, a centimeter below the surface, suggested that scientists found what they were looking for: ice made of water. 

An image, taken June 15, shows small white cubes in the corner. Four days later, they are gone. The scientists say the ice vaporized after exposure to Martian air.

"We have found the proof that we've been seeking to show that this hard bright material is really water ice and not some other substance," Peter Smith, a project scientist said.

Roger Launius is a space historian at the National Air and Space Museum in Washington DC.

"It is enormously significant because water, liquid water specifically, but water in any variety is the fundamental building block of carbon-based life as we understand it," Launius said. "So having it present there and perhaps having it present in great abundance might mean that there was life that evolved on Mars."

The scientists hope to drop soil with ice into small ovens on the lander for analysis. That could provide information about the climate history of the red planet and possible evidence of organic compounds.

"If we can show that right here in our solar system that life started twice, independently. Then that would tell us, I think conclusively that life is common in the universe,"  NASA scientist Chris McKay said. 

The Phoenix lander arrived on Mars on May 25. The mission team expects to learn more about the soil - and the ice - in the weeks ahead.