Mars missions- Is Mars a backup planet?

A backup planet?

• Mars as a backup site for humanity to migrate to; is being promoted as such by avant-garde entrepreneurs like Jeff Bezos and Elon Musk.

Findings of Mars missions

• Mars Express satellite: In 2005, the Mars Express satellite found evidence of clays that may have formed after solid rocks were exposed to water, as analogous examples of Earth’s rock inventory would testify.
  • But some scientists were not easily convinced as their Martian climate models failed to predict temperatures high enough for continuous generation of rain to have liquid water on the surface.
  • So, it was concluded that any water on Mars would have been locked up in its polar regions with brief periods of melting and flooding that carve out the valley networks.
• Possibility of underground niches: Though Martian climate may not have been stable, a corollary explanation holds the promise of life in the underground niches, where stabler conditions could have prevailed. Such examples of subsurface life are plenty in Earth’s environment.
• Carbon-containing compounds: The predecessor of Perseverance, the Curiosity rover, which has been surveying and testing the Martian surface since 2012, added some interesting findings.
  • Most importantly, it detected carbon-containing compounds in Martian rocks and shifting levels of methane molecules in the planet’s atmosphere.
  • Two papers published in the journal Science in 2018 concluded that these findings support the possibility of the existence of microbial life.
• Possibility of algal mats: Perseverance, with its companion, the Ingenuity drone, is the most complex rover ever sent to Mars.
  • It has now reached its destination, the 45-km-wide Jezero Crater, where an old lake supposedly existed.
  • The rover will roam around this crater and sample carbonate rocks that might host algal mats called stromatolites, as we find in the oldest carbonate rocks on Earth.

Why can’t the rovers on Mars collect samples of organic matter?

• The complex factors that control the preservation potential of organic matter and other biosignatures in the four-billion to 3.5-billion-year-old phyllosilicate-rich terrain of Mars, show evidence of sustained weathering of sediments with liquid water.
• Like the rusty red and iron oxide-rich lateritic soil we see in the tropical regions of Earth, the weathered soil formation of Mars may be a poor medium to preserve biogenic signatures.
• That could be one reason why the Perseverance rover is programmed to seek carbonate rocks within the Jezero crater, where the pristine nature of the original biological and climatic signals is expected to be preserved better.
• We still do not understand the mechanisms of the formation of carbonates on Mars and whether they are comparable to Earth’s processes, which are often related to oceanic settings.

Conclusion

• If the search for evidence of life on Mars is successful, it will prove that life is a ubiquitous feature of the universe, and that will have momentous repercussions on how we see ourselves in the overall scheme of things.