Viruses are the most abundant and one of the least understood biological entities on modern Earth. They might also exist in space, but as of yet scientists have done almost no research into this possibility. Portland State University’s Professor Ken Stedman and co-authors hope to inspire integration of virus research into astrobiology.

Viruses are an integral, highly abundant yet underappreciated part of life on Earth.

They are highly diverse both in structure and genomic sequence, play a critical role in biogeochemical cycles and evolution. However, there is yet very little focus on viruses in astrobiology.

Professor Stedman and his colleagues from the University of California, Berkeley, and Tokyo Institute of Technology are trying to change this through their article published in the February issue of the journal Astrobiology.

“More than a century has passed since the discovery of the first viruses,” Professor Stedman said.

“Entering the second century of virology, we can finally start focusing beyond our own planet.”

“Virions — the extracellular form of viruses — are the most abundant biological particles on Earth, with an estimated 1031 virions in the oceans alone,” the scientists said.

“Whether this amazing virion abundance is true in extraterrestrial oceans or was true in primordial Earth oceans are open questions.”

“Unfortunately, the lack of validated virus biosignatures makes detection of extraterrestrial or ancient viruses challenging.”

In their call to arms, the researchers state that NASA and other space agencies should be looking for viruses in liquid samples from Saturn and Jupiter’s moons, develop technology to detect viruses in ancient deposits on Earth and Mars, and determine if Earth viruses could survive in space.

They explained: “priorities for future astrovirology research in the short term should include:

(i) validation of virus biosignatures;

(ii) consideration of virus-detection experiments to be used for missions that sample water plumes from Enceladus and Europa;

(iii) inclusion of viruses in models for ancient oceans and extraterrestrial systems;

(iv) determination whether virus-encoded and transferred AMG (auxiliary metabolic genes) fractionate isotopes differently than their cellular counterparts.”

“In the longer term, astrovirology objectives should include:

(i) more exposure studies of viruses, particularly endolithic viruses, to the space environment;

(ii) characterization of highly abundant cosmopolitan viruses;

(iii) greater research into the roles of viruses in the origin and evolution of early life;

(iv) more outreach to astrobiologists and the general public regarding the ubiquity and role of viruses in Earth’s ecosystems.”

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Aaron J. Berliner et al. Astrovirology: Viruses at Large in the Universe. Astrobiology, published online January 10, 2018; doi: 10.1089/ast.2017.1649