The quest for extraterrestrial life: what about the viruses?

Area of Science:

• Astrobiology
• Virology
• Evolutionary Biology

Background:

• Viruses are the most numerous entities on Earth and crucial drivers of evolution.
• Historically, viruses were overlooked in astrobiology due to perceived non-living status and host specificity.
• Current understanding suggests viruses are likely encountered on other life-bearing planets.

Purpose of the Study:

• To re-evaluate the significance of viruses in the field of astrobiology.
• To highlight the potential prevalence and characteristics of extraterrestrial viruses.
• To inform protocols for encountering potential extraterrestrial viral life.

Main Methods:

• Review of current virological and astrobiological knowledge.
• Analysis of viral survival and host-interaction capabilities in extreme environments.
• Assessment of potential risks associated with extraterrestrial viruses.

Main Results:

• Viruses are likely prevalent on other life-bearing planets.
• Many viruses exhibit broad host ranges and can survive in extreme conditions.
• Some viruses can persist outside hosts for extended periods, especially in cold environments.

Conclusions:

• The search for extraterrestrial life should include a focus on viruses.
• While many viruses may pose no risk, the potential for encountering novel, multi-host viruses necessitates caution.
• Protocols for handling potential extraterrestrial viral encounters should be developed.