With uncertainty around life on Mars, human visits present an ethical dilemma

Bob McDonald · CBC Radio

· Posted: May 23, 2025 1:58 PM EDT | Last Updated: 6 hours ago

The archetypal measurement by a quality connected the aboveground of Mars will inevitably transportation Earthly microbes onto Martian soil. Scientists are progressively acrophobic with what the implications of contaminating different satellite volition be. 

A caller study, published this period successful the diary Microbiome, analyzed the cleanable rooms astatine the Kennedy Space Center, wherever Mars landers are sterilized earlier launch. The team found 26 taxon of caller bacteria that could perchance past the harsh situation of space.

These organisms incorporate genes that heighten DNA repair, detoxification of harmful molecules, and heighten metabolism, each of which makes them more hardy.

NASA goes to large lengths to guarantee immoderate spacecraft that departs for Mars is sterilized successful these ultra-clean rooms and sealed successful capsules earlier motorboat to forestall cross-contamination betwixt 2 planets. 

We don't cognize whether immoderate of these microbes really made it to Mars due to the fact that we person nary mode of examining the spacecraft portion they are connected the Red Planet.

The chances of microbes surviving the vacuum of space, utmost temperatures, on with star and cosmic radiation are slim, nevertheless determination was a lawsuit wherever Earth microbes did look to past for years connected the moon. 

In 1969, the unit of Apollo 12 landed adjacent to a robotic probe called Surveyor 3 which had arrived connected the lunar surface three years earlier. The astronauts removed a tv camera, electrical cables and a illustration scoop which were returned to Earth for survey connected the agelong word effects of vulnerability to space.

To everyone's surprise, a communal bacteria, Streptococcus mitis, was recovered wrong the camera lens. This harmless organism, usually recovered successful the rima and pharynx of humans, was thought to person been connected the spacecraft earlier motorboat due to the fact that Surveyor was not sterilized.

A aboriginal study done by NASA successful 1998 suggested the bacteria could person travel from contamination owed to mediocre procedures aft the lens was returned to Earth. But determination is inactive the anticipation that microbes could past successful space.

Sterilizing a robotic spacecraft to forestall contamination is 1 thing, but sterilizing quality beings is impossible. We are substantially made of bacteria, covered successful microbes from caput to toed and internally, perpetually shedding them with dormant tegument and different detritus. And those organisms volition question with america to Mars.

WATCH | Saturday cleaning time connected the Space Station: 

New taxon of bacteria person been recovered wrong China's Tiangong-1 abstraction presumption and astronauts connected the International Space Station are perpetually cleaning the walls to forestall the buildup of microbes successful that sealed environment. This is grounds that bacteria tin past the higher radiation situation of a abstraction habitat. 

That means immoderate quality footwear that touches the Martian ungraded volition bring with it organisms from wrong the spacecraft oregon colony. Whether those bugs could past agelong successful the Martian situation is to beryllium determined, but the much superior contented is what they would bash to immoderate indigenous organisms that could already beryllium surviving connected Mars. 

Curiosity, 1 of the rovers presently driving astir connected the Red Planet, has been collecting ungraded samples from antithetic areas and sealing them successful tubes to beryllium collected and returned to Earth by a aboriginal illustration instrumentality mission. The thought is to look for signs of existent beingness oregon fossils of past beingness utilizing the almighty tools successful Earth laboratories.

But NASA is proposing cancelling the illustration return, truthful we whitethorn not cognize for immoderate clip whether microbes beryllium successful Martian soil.

Mars shows signs of a lukewarm and bedewed past, wherever the satellite was erstwhile covered with lakes, rivers and oceans. This was during a time, astir 3 cardinal years ago, erstwhile beingness was emerging connected Earth. So far, nary signs of beingness person been recovered connected Mars, but we person lone been looking connected the surface, not underground wherever h2o mightiness exist.  

Still, determination is speech of sending radical to Mars, adjacent establishing a Mars colony. But is that omniscient earlier we find whether the satellite has beingness oregon not?

In the classical subject fabrication story, War of the Worlds by H.G. Wells, Martians travel to Earth with invincible machines that wreak havoc connected cities. Our astir almighty weapons are useless against their unthinkable power. But eventually, the invaders are taken down by the tiniest creature, the communal cold, for which they had nary resistance.

In existent life, the tables are turned. We are the invaders from Earth who are bringing our machines and alien organisms.  If we bash observe Martian life, should we spell determination astatine all?