Part of me is a very rational, level-headed human being. The other part of me really wants to believe in extra-terrestrial life. Apparently, this is also tempting for NASA scientists, who are searching for any evidence of life-giving elements on Mars. And it seems that they may have caught a break.
Photos taken by the Mars Reconnaissance Orbiter show dark streaks on Mars’s steep slopes during the planet’s spring and summer seasons. Scientists believe that these streaks are evidence of flowing water currently present on Mars. Water, combined with carbon and an energy source, is a main ingredient to life as we know it. This means that Mars may currently be a life-sustaining planet.
Up until now, only dry riverbeds and ice had been found on Mars, leading some scientists to believe that water had once been present and was no longer, or that the planet was simply too cold to sustain life. Others hypothesized that Mars was home to the types of organisms that survive in very salty water, which freezes at much lower temperatures than fresh water and could therefore remain in liquid form at Martian temperatures. The types of salts that would facilitate this have been detected in solid form all over Mars. Still others say that if liquid water is only present for part of the year, which seems to be the case, organisms can remain dormant in the ice for extended periods of time.
Compelling as it is, the evidence is only circumstantial. The probe has been unable to detect any actual water, despite technology that allows it to do so. Scientists also cannot explain with certainty why water would darken the soil or why the streaks disappear in the winter. There are also only a few sites on the planet with such streaks and no explanation as to why water would only flow in those areas.
Further experimentation won’t be easy. The next Mars probe, launching later this year, will not land anywhere near the site of the streaks, nor is it equipped to navigate the steep slopes. According to Dr. Lisa M. Pratt, a biochemist at Indiana University, testing whether salt water can remain liquid and life can be sustained in the Siberian permafrost might be as close as we can get to actual experiments on Mars. Whether any of these developments points to real-life aliens remains to be seen.