Martian rocks shaped by water (Photo: NASA)
In the breathtaking glamor and celebrity of the images being regularly produced by the James Webb Space Telescope, it is easy to forget the grunt work phase of NASA’s Perseverance rover on Mars going on right now. But it is my job to keep track of such work, or at any rate, I have made it my job to do so.
Reading a paper in the journal Science Advances this morning one is excited that the rover is producing some remarkable results. It has collected Martian rocks in the Jezero crater floor, shaped by water that could possibly contain biosignatures or signs of life. What is even more exciting is that these rock samples will be brought back to Earth by the 2030s.
The paper’s abstract, a bit too science-y for the lay readership, says, “The potential for secondary aqueous phases to preserve evidence of life depends on how they formed. On Earth, studies of evaporitic and desert environments demonstrate the presence and preservation of microbial life in association with salts. Carbonate veins on Earth, produced through serpentinization and carbonation, can preserve biomarkers such as lipids and/or organic structures interpreted as fossilized microbial communities. By analogy, we propose that the secondary phases in the altered igneous rocks of the Jezero crater floor might have the potential to record biosignatures, if ancient habitable environments existed.”
This is a big deal in our quest to look for life other than on Earth and perhaps by far the most promising find.
The paper says, “Laboratories on Earth have measurement capabilities superior to instruments which can be mounted on a Mars rover. An objective of the Mars 2020 mission is therefore to collect samples, in the form of drilled rock cores, for potential transport to Earth by another spacecraft in the 2030s. We attempted core acquisition on three different rock targets: two in the Máaz formation and one in the Séítah formation. The first coring attempt occurred near Guillaumes, in the low-lying, polygonal pavement of the Roubion member of the Máaz formation. Although the sample collection process appeared to execute as expected, the sample tube was subsequently found to contain no rock or rock fragments. A likely explanation is that this rock disintegrated during drilling, likely due to the rock’s aqueous alteration (Fig. 3A). The sample tube was sealed and instead provides a sample of ambient Martian atmosphere. A second sample acquisition attempt was performed on the Rochette member on the crest of Artuby ridge near Bellegarde, and a third on the Séítah formation Bastide member near Dourbes; these were both successful.”
Reading this extensive paper, something I have always enjoyed, one is once again struck by how life, therefore the universe is all chemistry governed by the laws of physics. Speaking of the laws of physics, the paper mentions the use of Raman spectroscopy 12 times; Raman being named after the Nobel Prize winning Indian physicist Chandrasekhara Venkata Raman whose pioneering work in studying the scattering of light using a spectrograph that he developed. “Raman spectroscopy indicates that the bright white void-filling material in the Máaz formation abrasion patches is at least partially composed of hydrous Ca-sulfate and Na-perchlorate, sometimes co-located with each other," it says.
How amazing it is that in science, discoveries come in handy decades, sometimes centuries, after they were made and irrespective of who made them. At its purest, science makes no distinction among people and countries.
The aqueous alterations in the Martian rocks that the paper talks about means changes and modification in rock shapes made by their interaction with flowing water.
While the paper may not interest a lot of people, apart from its pure science what draws me to it are occasional interesting turns of phrase such as “Carbonate veins on Earth, produced through serpentinization.”