Scientists suggest in recent research that the increased need for space travel increases the likelihood of alien creatures conquering Earth and Earth-based organisms infecting other worlds.
According to the paper, published Nov. 17 in the journal BioScience, the researchers point to humanity’s record of moving species to new environments on Earth, where those organisms can become invasive and harm native species; they say such behavior suggests the same could happen with alien life from another planet contaminating Earth and vice versa.
“The quest for life outside our world is an intriguing endeavor that might produce a massive finding in the not-too-distant future,” said lead author Anthony Ricciardi, a professor of invasion biology at McGill University in Montreal, in an email to Live Science. “However, with the rising number of space missions (including those aimed at returning samples to Earth), it is critical to decreasing the hazards of biological contamination in both directions.”
The work by Ricciardi and his colleagues calls for increased collaboration research between astrobiologists looking for alien life and invasion biologists examining invasive organisms on Earth. “We can only hypothesize on what types of species astrobiologists could encounter if they uncover life,” Ricciardi added. “The most likely life-forms would be microbiological and would most likely resemble bacteria.”
The scientists believe the danger of interplanetary contamination is extremely low, in part because the harsh conditions of deep space make any hitchhiking organisms unlikely to survive a journey on the exterior of a human spaceship. However, based on the detrimental consequences that invading species have had on Earth, we should still be wary about interplanetary contamination, according to Ricciardi.
Humans have harmed ecosystems all across the globe by permitting species to invade new places that they would never have reached on their own. For example, Austropuccinia psidii, a fungus from South America, was unintentionally brought to Australia and is now wreaking havoc on the country’s native eucalyptus trees, slowing their development and occasionally killing them.
The researchers stated that insular ecosystems that form in geographical isolation, such as those found on islands and in nations such as Australia, are particularly vulnerable to invasive species since local fauna in those areas has not evolved mechanisms to deal with such intruders. “Biological incursions have frequently proven deadly for the plants and animals in these systems,” said Ricciardi. “We believe that planets and moons that may harbor life should be handled as if they were isolated systems.”
The researchers cited the Israeli Beresheet spacecraft, which crashed into the moon in 2019 while carrying thousands of tardigrades, microscopic animals that can survive extreme conditions, including the vacuum of space, as evidence of interplanetary contamination, as previously reported by Live Science. According to a 2021 research published in the journal Astrobiology, the animals would not have survived the impact of the lunar fall, but the occurrence indicates the possibility for biological leaks.
According to Ricciardi, space agencies such as NASA have long been aware of the possible consequences of biological contamination, and planetary protection measures have been in existence since the 1960s. “However, a new phase of space research geared at targeting places most likely to harbor life poses enormous hazards,” Ricciardi warned. According to the report, this includes the growth of commercial space exploration businesses such as SpaceX, which are making space more accessible. With the SpaceX Starship program, for example, SpaceX intends to go to Mars and beyond.
The researchers recommend that biosecurity policies related to space flight be strengthened, with an emphasis on early detection of possible biological pollutants and the development of strategies for a swift reaction to any such detections.
Meteorites have always moved material between planets and moons, but human space travel might increase contamination, according to Jennifer Wadsworth, an astrobiologist at Lucerne University of Applied Sciences and Arts in Switzerland who was not involved in the study.
Wadsworth described the new report as a “great review” of the existing and ongoing need for stringent and up-to-date planetary protection measures. Wadsworth told Live Science that one big issue is that present planetary preservation measures are not mandatory.
“The boundary between exploration and conservation is really narrow,” Wadsworth explained. “Neither should be abandoned at the expense of the other, but both need careful thought and, most crucially, compliance.”
