A new feature has shown up on Mars photographs which was not present before 2010. The photo has caused a stir, since the feature seems to the naked eye to indicate the presence of seasonal water flows on the Red Planet. The new gully on Mars appears to be only three years old, since it did not show up in photographs of the same area in past surveys. The find has once more kicked up the debate on what locating liquid water on the Red Planet might mean regarding the possibility of life on Mars.
Scientists are working to decode the possible meaning of the photograph, which shows a feature similar to those caused by flowing water here on Earth, and which was not present in the 2010 photos of the same region. The shape and structure of the feature, at first glance, seems to indicate that water flowed out from a previously existing gully to form this new one in the interim.
Scientists who specialize in Martian conditions and terrain, however, caution that this feature was not likely to have been formed by flowing water of the kind that would sustain life. The findings were released with a statement which indicates that since the feature appeared during the Martian winter, carbon dioxide would be a more likely culprit at those temperatures.
Another possibility is that water could be present, being melted somewhat by the presence of ferric sulfate in the water. This naturally occurring chemical would act like antifreeze, and has been found in other areas where dark lines occur to show that water might be flowing on Mars in the right conditions. The presence of this chemical in Martian water, however, would make it unlikely to sustain life.
This new feature and others containing the traces of iron found around the new, only three-year-old gully do have fascinating implications in the search for liquid water on Mars. Any water, even briny water which could not sustain life, would teach us a great deal about the way the planet functions, and the way it might have functioned in a past in which water could have survived without the antifreeze component.
The photos which jump-started the debate were taken by High Resolution Imaging Science Experiment (HiRISE), the camera on the Mars Reconnaissance Orbiter. The MRO took photos of the same area three years ago and recorded older gullies, but not the same feature currently under study. Though research indicates the feature is unlikely to have been formed by useful water due to temperatures in Mars’ cold season, there are other candidates for the job.
Photos taken elsewhere on the planet’s surface do show seasonal streaks called Recurring Slope Lineae, which indicate there might actually be flowing water on the Red Planet during warmer months. The formation of these new features and gullies on the Red Planet might help to define what it might mean to find liquid water, and by that, perhaps the parameters of possible life on Mars. Because of this possibility, each time there is evidence of water on Mars, the MRO’s spectrometer does a scan to ascertain the make-up of the deposits nearby to see if water was flowing or present at the site. This spectrometer did not find indications of water in the area where the new gully formed, but has found traces of iron which might indicate the antifreeze-type chemical at these other sites.
The goal of finding evidence of life on Mars has been an ongoing one for decades, and has been a fascination of modern humanity since telescopes were made that were strong enough to focus on our closest planetary neighbor and see the formations on its surface that resembled the waterways of Earth. It is highly likely that liquid water existed at one time on Mars, before changes to the orbit or atmosphere altered the climate so that all liquid water that we know of now remains locked in ice at the poles. If some form of liquid water could be found on the Red Planet now, the search for life on planets other than Earth could be a short step away.
The photographic evidence of a new, three-year-old gully on the Mars surface has brought new life to the debate about whether water exists on our closest planetary neighbor only in the form of ice, or whether liquid water may sometimes flow there. Though this feature has been found to be caused by other natural phenomena, evidence exists for liquid water elsewhere on the planet. It would mean a great deal to science and to human understanding of how life could evolve on other planets if water could be found in such gullies on Mars in an unfrozen state. If free-flowing water does exist somewhere on the Red Planet, it is still possible that life does as well.
By Kat Turner