The study, published in the journal Geophysical Research Letters, noted that the crater, named Jazero, contains a large delta deposit formed by ancient rivers that fed an ancient lake.
Researchers, using data from NASA’s Mars Reconnaissance Orbiter, have found deposits of hydrated silica — a mineral good at preserving chemical signatures of life — in a crater on the Red Planet where the US space organisation plans to land a rover next year. The study, published in the journal Geophysical Research Letters, noted that the crater, named Jazero, contains a large delta deposit formed by ancient rivers that fed an ancient lake. The researchers, including those from Brown University in the US, used the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument that flies aboard NASA’s Mars Reconnaissance Orbiter, and applied big data analysis methods to tease out the weak spectral signature of the silica deposits. They said the delta would have concentrated a wealth of material from a vast watershed, similar to deltas on the Earth which are good at preserving signs of life.
According to the researchers, finding hydrated silica at Jezero, increases the preservation potential of chemical signatures of life. They said, one of the silica deposits was found on the edge of the delta at low elevation. “The material that forms the bottom layer of a delta is sometimes the most productive in terms of preserving biosignatures. So if you can find that bottomset layer, and that layer has a lot of silica in it, that’s a double bonus,” said study co-author Jack Mustard, a professor at Brown University. The study noted that the minerals may have formed in the discovered region, and may represent the bottom layer of the delta deposit. The researchers said it is also possible that the minerals could have formed upstream in the watershed that fed Jazero and may have been washed subsequently into the crater, by volcanic activity or later episodes of water saturation in the crater lake.
The rover should be able to isolate the real source, the researchers said. “We can get amazing high-resolution images and compositional data from orbit, but there’s a limit on what we can discern in terms of how these minerals formed,” Jesse Tarnas, study co-author at Brown University, said. “Given instruments on the rover, however, we should be able to constrain the origin of these deposits,” Tarnas added. The researchers said the rover will be able to perform fine-scale chemical analysis of the deposits. This can provide a close-up view of how the deposits are situated in relation to surrounding rock units, they said.
Another instrument aboard the rover, the researchers said, can look for complex organic materials. If the silica deposits have high concentrations of organic compounds, it could be an intriguing find, they said. “If these deposits present themselves in the form of rocks that are big and competent enough to drill into, they could be put into the cache. This work suggests that they’d be a great sample to have,” Mustard said.