Searching for Life in the Solar System | Alfonso Davila | Talks at Google

TL;DR

The search for life in the universe involves exploring different planets and moons, such as Mars, Europa, and Enceladus, to determine if a second genesis of life exists. Scientists rely on the understanding of organic chemical evolution to guide their search for bio-signatures and evidence of life.

Transcript

[MUSIC PLAYING] SPEAKER: But today, we have a very exciting speaker here, Alfonso Davila. Alfonso. And he's here from Ames. He's been with Ames about 10 years, and has just recently become a civil servant, and before that was a contractor with SETI working at Ames. So. He is currently in the exobiology branch of NASA Ames, looking at terrestrial an... Read More

Key Insights

• 🛟 The search for a second genesis of life is driven by the need to understand the origin and possibilities of life beyond Earth.
• 🥮 Studying the organic chemistry of other planets and moons can provide insights into the likelihood of a second genesis.
• 😚 There is a need to differentiate between a close second genesis, where life originated from similar starting materials, and a distant second genesis, which would involve completely different biochemistry.

Questions & Answers

Q: How do scientists differentiate between a close second genesis and a common ancestor when searching for life on other planets?

Differentiating between a close second genesis and a common ancestor is challenging since our knowledge of biochemistry is limited to LUCA, the last universal common ancestor. If we find evidence of life on another planet that we cannot explain based on abiotic processes, we can infer the presence of a second genesis, but determining if it is a close second genesis or a common ancestor is difficult without further evidence.

Q: Can life on other planets exist without biochemistry?

Life, by definition, involves biochemistry. However, the biochemistry of life on other planets may be different from what we consider to be familiar. For example, silicon-based life has been theorized, but it is not known if such life forms exist. It is challenging to speculate on the possibilities of life beyond our current understanding of biochemistry.

Summary & Key Takeaways

• The speaker discusses the motivation behind the search for a second genesis of life and the importance of asking the question "why?" in scientific exploration.

• The possibilities of a second genesis of life are explored, including a potential common ancestor, a close second genesis with similar starting materials, and a distant second genesis with completely different biochemistry.

• The speaker proposes a two-fold hypothesis to guide the search for a second genesis of life: the abiotic null hypothesis which looks for evidence of prebiotic chemistry, and the terrestrial null hypothesis which examines the possibility of contamination or transference of Earth life.