What Are Alternative Biochemistries for Alien Life?

TL;DR

Alternative biochemistries for alien life could include silicon-based life, life utilizing arsenic or borane, and organisms existing in different solvents like ammonia or methane. Recent research into autocatalytic reactions suggests these forms of life might be more common than previously believed, raising the possibility of diverse biochemistries beyond carbon-based life.

Transcript

Within astrobiology and thinking about alien  biochemistry there is a known bias. This   bias is quite simply that we’ve only ever seen  one brand of life, our own. All life on earth   adheres to a set of rules and chemistry  based on carbon that while successful,   may also blind us to the possibilities of  life that simply doesn’t work like anyth... Read More

Key Insights

• 🛟 Earth's dominant carbon-based life may hinder our ability to recognize non-carbon based life elsewhere in the universe.
• 🛟 Alternative biochemistries could include alternative chirality, incorporation of arsenic, borane biochemistry, and life in different solvents.
• 🤨 The existence of shadow biospheres on Earth and the possibility of panspermia raise questions about the presence of unrelated life forms.
• 💁 Autocatalytic reactions may support alternative forms of biochemistry and have potential applications in chemical computation.

Questions & Answers

Q: What is the known bias in astrobiology regarding the search for alien life?

The bias in astrobiology is that we have only ever observed one kind of life - carbon-based life on Earth. This limits our understanding of the possibilities of non-carbon based life forms.

Q: Why do scientists focus on Earth's kind of life in astrobiology?

Earth's life has been successful for over 3.8 billion years, and we have not observed independent life of a different kind on Earth. This suggests that our kind of life has dominated and potentially eliminated other biochemistries.

Q: What is the shadow biosphere?

The shadow biosphere is a hypothetical concept suggesting the existence of unrelated life forms on Earth that do not conform to our kind of life. These forms of life may exist, but our current microbial detection methods may not be able to identify them.

Q: What are some potential forms of non-carbon based life?

Some potential forms of non-carbon based life include alternative chirality, where biomolecules have different handedness, arsenic life that incorporates arsenic instead of phosphorus, borane biochemistry, and life in different solvents such as ammonia or silicon dioxide.

Summary & Key Takeaways

• Earth's life adheres to a set of rules and chemistry based on carbon, which may hinder our ability to recognize non-carbon based life forms.

• Earth has not seen a second abiogenesis, which suggests that new biochemistries may be immediately interfered with by preexisting life.

• There may be a shadow biosphere on Earth, where unrelated life exists, but our microbial detection methods may not recognize it.