University of Arizona’s Sukrit Ranjan has spearheaded a pathfinding study. The scientists suggest an ambitious new strategy for determining whether life originated on Earth or elsewhere in our solar system using the future Habitable Worlds Observatory (HWO). The astrophysical research will focus on at least 50 exoplanets. Specifically, it will address the social determinants of life and how quality of life intersects with historical ultraviolet (UV) irradiation exposure. This study, which is now available on arXiv with the DOI 10.48550/arxiv.2507.00164, could provide critical insights into one of humanity’s most profound questions: how did life begin?
Our research is focused on three broad categories of hypotheses about the origins of life. Each of these groups of scientists offers different predictions about what conditions are required for life to develop. By taking a really large sample size of exoplanets, Ranjan and his team want to scientifically test these theories.
The Role of HWO in Exoplanet Research
The Habitable Worlds Observatory—a future space telescope that’s part of the large strategic science program—will provide key support for this research pilot program. It is intended to study a diverse set of exoplanets, including all of them up to about 33 light-years away from Earth. The HWO will leverage cutting-edge technology to characterize exoplanets. Specifically, it will study their atmospheres and surface conditions to look for biosignatures – indications of life.
The choice of minimum 50 exoplanets is important to ensure the success of the study. With enough sample size researchers will be able to make more conclusive statements about how common or rare life is across the universe. By comparing the UV irradiation history of these planets with evidence of life’s presence or absence, the team hopes to reveal meaningful correlations that could either support or refute existing theories.
Implications for Theories of Life’s Origins
The implications of this research are significant. Should researchers discover a single biosphere among the examined exoplanets, it would challenge prevailing theories that suggest life is exceedingly rare in the universe. If we don’t see any signs of life after visiting 20 to 50 planets, it would begin to corroborate the rarity hypothesis. This implies that the conditions that allow life to thrive are far rarer than we once thought.
The three groups of origin theories that Ranjan’s research addresses each make distinct predictions about life’s emergence and its relationship with environmental factors like UV radiation. By testing these theories against empirical data from the HWO’s observations, the research aims to clarify existing ambiguities and potentially redefine our understanding of life’s origins.