Mars life explorer should include an agnostic life finder

Searching for life on Mars has been an explicit goal of the astrobiological community for decades. However, they have not really had the resources to effectively do so, and they might be running out of time. Crewed missions to Mars are planned for as little as 15 years from now (though those timelines might be changing…again), and by the time that happens it may be too late to separate Martian life from unintentionally transplanted Earth life.

According to a group of researchers from the Agnostic Life Finding Association, there is one final chance to detect Martian life before it is irreversibly contaminated—the Mars Life Explorer (MLE). But to do its job properly, it’s going to need an upgrade. The study is published on the arXiv preprint server.

MLE itself isn’t even a completely funded mission yet. Its objective would be to fly to Mars in the 2030s and search for signs of extant (not ancient) life, mainly by using a drill to drill into some water ice that exists near to the surface at a mid-latitude range on the Red Planet and analyzing that water sample for biological molecules.

It wouldn’t be the first experiment to try to capture those molecules, though. The Viking landers, which landed on Mars almost 50 years ago, also tried to capture biological materials, and provided famously ambiguous results. To this day, there is still debate among the scientific community as to whether or not Viking found life on Mars, yet no one has followed up the ambiguous Label Release experiment it performed with another one.

Enter MLE—the express intent of the Mars Life Explorer is in the name. But, according to a new paper from Gabriella Rizzo and Jan Spacek of the Agnostic Life Finding Association (ALFA), its current suggested suite of equipment would only look at the current habitability of Mars, rather than finding any evidence of actual life. More specifically, it would be limited to finding only life like that which appears on Earth.

The authors point out that “research in ultra-low-biomass ecosystems on Earth, such as hyper-arid deserts and high-UV environments, has shown that instruments traditionally used in astrobiology often lack the sensitivity needed to detect life under such extreme conditions.”

In other words, the systems that we have previously put in place, and those planned for the MLE, won’t do their job correctly. MLE’s suite of instruments both won’t find life at extremely low concentrations, but it also won’t be able to deal with any life that doesn’t have a biochemistry similar to ours. Assuming there are large amounts of biochemically similar life on Mars are two very large assumptions that the ALFA team hope to eliminate.

Their suggestion is known as the Agnostic Life Finder (ALF), which was originally developed up to a Technology Readiness Level 4, meaning they’ve built a bench-top prototype, by a NASA Institute for Advanced Concepts grant. The ALF itself uses a system of chambers, filters, and an electric charge to separate organic molecules, which are charged, and large, from other potential components in a liquid environment, such as ions or non-charged particulates.

According to the paper, the best use case for the ALF would be in a tank where massive amounts of Martian water is collected before the first crewed missions. This water collection is widely considered to be a necessary step in the development of a permanent Martian presence, but it’s unclear when, or if, either the private space companies that seem best placed to do so first, or a government space agency that decides to take that first leap, will prioritize building such a water capture and storage system. In the meantime, joining the payload of MLE, which isn’t necessarily going to the same place as future astronauts might, is the best bet for the system.

Given the budget cuts that are happening throughout NASA, it is unclear at this point whether MLE is even going to be funded at all, despite being one of the highest priority suggestions in the latest Planetary Decadal Survey. While the ALF itself is a relatively simple instrument, it does need to get to Mars somehow, and until it finds a ride the best the ALFA team can do is continue testing and development. But maybe some day someone will pick up the idea and give it a chance to answer one of the most important questions in astrobiology once and for all.