Herein is a copy of the official White Paper submission to NASA-DARES 2025 Request for Information by Christopher Temby on behalf of the Agnostic Life Finding Association (ALFA)
Cite as: Temby, C. (2025) “Prioritize the Search for Extant Life on Mars with NASA-DARES 2025.” Primordial Scoop, e20250210. https://doi.org/10.52400/OJTV9012
“Over the past two decades, MEP missions have successfully determined that Mars has had habitable conditions… With that knowledge, Mars missions are transitioning toward seeking life itself.” – Mars Future Plan: 2024-2044 by NASA’s Mars Exploration Program
1. Introduction and Recommendation
NASA’s Science Mission Directorate (SMD) and Mars Exploration Program (MEP) are hereby recommended by Christopher Temby and Agnostic Life Finding Association [1] to ensure that the highest priority science objective in the coming decade for the 2025 Decadal Astrobiology Research and Exploration Strategy (NASA-DARES 2025) is a search for an extant Martian biosphere before human arrival. Relevant to NASA-DARES 2025 RFI’s Response Topic 7 [2], this recommendation 1) reflects the shrinking timeline for thorough astrobiological investigation on a pristine Mars, 2) addresses contradictions within planetary protection protocols, 3) will inform risk assessments for all future missions to the Red Planet and 4) will inform the development of all future missions searching for life.
A Search For extant Life (SFL) beyond Earth has been conducted only once: Viking, 1976 [3]. Interpretations of the Viking biology experiments at the time declared the absence of extant Martian life [4]. However, the ambiguous results from Viking’s experiments remain debated to this day [1-7]. Accordingly, in the decades that followed, NASA was apprehensive to further investigate the results of the Viking biology experiments, instead choosing to shift the programmatic approach of Mars exploration towards more easily defined objectives, such as “follow the water,” [8]. While this approach has provided a sustained functionality for the MEP, and significant context for each subsequent discovery, it has been directly circumventing one of NASA’s prime directives: search for life.
The reluctance to follow up the Viking biology experiments suggests to the modern critic that the community has viewed it unlikely that life can currently live on Mars and/or that a search for extant alien life can yield an unambiguous result. To the contrary, as noted by MEP in the excerpt that introduces this document, these statements are plausible and this should be reflected in NASA-DARES 2025 priorities.
Scenarios in which a SFL mission results in a positive detection of alien life are addressed by RFI Response Topic 8 [2]. Confidence in a positive result shall arise through the detection of predetermined biosignatures that satisfactorily “climb” the “Ladder of Life Detection” [9]. On the other hand, while an absence of evidence is not evidence of absence, a SFL mission that finds no evidence of life can still yield a result with confidence limits. Confidence in a “no life” result shall arise through measurements with sufficient orthogonality and high sensitivity, on sufficiently large samples, to establish the lowest possible limit of uncertainty. Notably, this is the opposite of what occurred on Mars in 1976: results from the less-sensitive GCMS instrument were invoked to dismiss the results of the more-sensitive LR experiment. The GCMS required the organic matter equivalent of about 1 million microorganisms for detection [10], while the LR required about 30 microorganisms for detection [6].
In the 50 years since Viking, the community has learned much about the survivability of life in extreme conditions. These findings suggest that the Martian subsurface is likely to be inhabited today, if life ever existed on Mars [11, 12]. Additionally, the community has developed several orthogonal life detection strategies to provide enough confidence in a SFL mission this decade [13-15]. This white paper discusses the rationale as to why a SFL on Mars must be the highest priority science objective established by NASA-DARES 2025.
2. Why a Search for Life on Mars Must be NASA’s Highest Priority
2.1. Growing Impetus to Put Humans on Mars Gives NASA Limited Time
Highlighted by the NASA-DARES RFI Solicitation [2], Response Topic 7 seeks to identify time-sensitive astrobiological investigations for the development of a decadal strategy. The SFL recommendation established within this document reflects the dwindling timeline for thorough astrobiological investigation at a pristine Mars. The arrival of humans, and their microbiomes, will inevitably bring significant biological contamination from Earth (forward contamination) to the Martian surface [16]. The contamination is unlikely to be a localized issue given that aeolian processes were shown to be sufficient to distribute material, including biological contamination, across the entire Martian surface [16-18]. Despite this, and more problematic because of no biology experiments being done on Mars since Viking, NASA, CNSA, and private entities are planning to send humans to the Red Planet in the next few launch cycles [19]. Human activities will lead to an increase in the amount of forward contamination, potentially hindering any subsequent studies of a tentative Martian biosphere. Therefore, the search for the extant life on Mars must be declared by NASA-DARES 2025 as the highest priority astrobiological target in the Solar System. No other astrobiological target will be affected by human presence in the coming decades. The gravity of this situation cannot be overstated.
2.2. Planetary Protection Protocols, Contradictions, and Knowledge Gaps Need Addressing
Additionally, this SFL recommendation will resolve contradictions within planetary protection protocols and address planetary protection knowledge gaps. A 2024 community report, Planetary Protection Knowledge Gap Closure Enabling Crewed Missions to Mars [18], highlights the importance of “protect[ing] the integrity of scientific investigations at Mars” from biological contamination of Earth material (for reasons discussed above, in Section 2.1). They also mention the importance of protecting Earth from the threat of a Martian biosphere. Conley and Rummel (2010) observed that “safeguarding the Earth from potential back contamination is the highest planetary protection priority in Mars exploration,” [16]. Interestingly, the level of risk associated with “the threat of a Martian biosphere” is entirely unknown, meaning this protocol cannot be adhered to with the current Mars exploration strategy (unless the safety of future astronauts – and Earth’s biosphere upon the astronauts’ return – is intentionally disregarded). Finally, the same 2024 community report states that “it is unlikely the search for life on Mars will be completed by the time the first crew systems arrive,” [18]. Given the inevitability of forward contamination, these are competing and contradictory statements: MEP cannot satisfy either of these highest-priority planetary protection protocols without a SFL.
The importance that mission planners place on planetary protection—as well as contradictions in the future enforcement of planetary protection protocols—is most evident when discussing Special Regions [20]. A Special Region is a “region within which terrestrial organisms may be able to replicate, OR a region which is interpreted to have a high potential for the existence of extant martian life,” [20]. The threat of affecting such locales has been taken so seriously that, even though the search for life is a driving motivation for Mars exploration, no mission has ever been approved to visit and investigate a Special Region. However, contradictions become apparent when considering the inevitable contamination of these Special Regions following human arrival. Just as astronauts see no defined borders between nations, Martian global dust storms will not be constrained in their redistribution of biological material from landing sites to Special Regions. Furthermore, if the Office of Planetary Protection plans to enforce planetary protection protocols that limit the ability to investigate portions of the Martian surface or subsurface, it will be unable to limit the actions of private entities and foreign adversaries.
Several planetary protection knowledge gaps (KGs) exist [18] and require investigation to close. Addressing these gaps is essential to reduce planetary protection risks, uncertainties, and costs in order to enable crewed missions to Mars. Highlighted by Spry et al. (2024) [18], KGs 1A, 2E, 2F, 2I, 2J, and 2K (and aspects of several additional KGs) can be closed by conducting a SFL on Mars before the first crews arrive, and continuing to monitor levels of extant (indigenous and introduced) life after human arrival. The only way to adhere to the highest priority planetary protection protocols is to conduct an SFL on Mars before human arrival.
2.3. All Future Missions to Mars will Benefit from a Search For Life in this Decade
This recommendation, to establish a SFL as the highest priority objective for Mars exploration in the next decade, may be seen to be disruptive to NASA’s SMD and MEP. It contradicts several previous community recommendations for a Mars Sample Return (MSR) campaign to remain the highest priority objective for NASA’s Mars exploration efforts. However, although MSR has been a top priority of NASA’s SMD and MEP for several decades, it is still far from completion, and continues to suffer intense programmatic change. Origins, Worlds, and Life: A Decadal Strategy for Planetary Science and Astrobiology 2023-2032 (OWL) [21] recommends that a SFL payload, exemplified by the Mars Life Explorer (MLE) mission concept study [22], should be MEP’s “next priority”, but only “subsequent to [the] peak-spending phase of MSR.” However, this recommendation should be taken in context: OWL also recommended to NASA that the MSR timeline and “cost should not be allowed to undermine the long-term programmatic balance of the planetary portfolio.” Unfortunately, that is happening.
Additionally, samples to be returned from Jezero Crater will retain a high scientific value regardless of when the samples are returned. The signs of extinct life that may be discoverable in the ancient dried rocks collected from the Martian surface will not be altered while they sit in their sample tubes; after >3 billion years, what is another decade or two? However, the same cannot be said about the scientific investigations to SFL in Martian subsurface ice after the introduction of human-associated forward contamination. Thus, after reassessing relevant budgets and timelines, NASA and the community must recognize that the current strategy does not provide sufficient time to SFL before human arrival.
Determining whether or not Mars hosts an active biosphere will inform (and possibly eliminate a number of) “break-the-chain” requirements for MSR and crewed missions [18]. Planetary protection knowledge gaps, extensive “break-the-chain” requirements, and costly planetary protection measures will be reduced by investigating a possible Martian biosphere. Notably, although not required for a successful MSR campaign, a SFL mission in this decade has the potential to greatly reduce the complexity and cost of the MSR architecture. This is especially true if the SFL enables crewed missions, and those crewed missions enable an easier return for the samples. Thus, NASA’s SMD and MEP should readjust their priorities to reflect the limited time to conduct, and the widely reaching benefit of, a SFL on Mars.
2.4. All Future SFL Missions will Benefit from a Search For Life on Mars in this Decade
Finally, it should be noted that technologies developed to SFL on Mars can be leveraged for subsequent missions to SFL elsewhere in the Solar System. Mars is less costly to study than other Solar System objects of astrobiological interest, and should serve as a ‘proving ground’ for future SFL investigations. This is supported by three key metrics of spaceflight: cost, ∆V, and time, all of which are significantly lower for delivering a SFL payload to Mars than elsewhere in the Solar System.
A framework can be established, taking inspiration from Rocket Lab’s Morning Star Mission: Venus Life Finder [23], for the creation of missions that reduce costs while maintaining high-value science objectives. This mission, the first private interplanetary mission, is estimated to cost around $10 million and was conceived of in 2021.
With adequate advocacy, motivation and funding, a SFL on Mars in the next decade can provide profound benefit to the Astrobiology and Mars Exploration programs. This starts by establishing, through NASA-DARES 2025, that NASA’s highest priority is a search for extant life on Mars.
References
[1] ALFA Mars. “Is there life on Mars?” www.alfamars.org
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