"We could very well be seeing rock, or we could be seeing exposed ice in the retrorocket blast zone," said Ray Arvidson of Washington University, co-investigator for the robotic arm. According to Arvidson, "We'll test the two ideas by getting more data, including color data, from the robotic arm camera. We think that if the hard features are ice, they will become brighter because atmospheric water vapor will collect as new frost on the ice."
"Full confirmation of what we're seeing will come when we excavate and analyze layers in the nearby workspace," he added. Another milestone for the mission included the activation of the laser instrument called light detection and ranging instrument (lidar), which is designed to detect dust, clouds and fog by emitting rapid pulses of green laser-like light into the atmosphere.
Lidar data shows dust aloft to a height of 3.5 kilometers.
The weather at the Phoenix landing site on the second day following landing was sunny with moderate dust, with a high of minus 30 degrees Celsius and a low of minus 80.