In the late 1960s, there was a race to be the first astronaut to set foot on the Moon. In the early 2020s, another race has begun to be the first astronaut to set foot on Mars. Every fan of science fiction dreams of being the first astronaut to leave our Solar System and set foot on a planet orbiting another star. It should come as no surprise that scientists are already planning that trip. However, before you update your resume and look for a line to stand in, their chosen first astronaut is one of those tiny water bears known as the tardigrade. While many humans may be disappointed if that happens – even though that first trip will probably be a one-way mission – fans of panspermia may be looking at this as a different kind of first … the first time a being from another star system came to Earth and then left to populate another one.
“Here we explore the biological and technological challenges of interstellar space biology, focusing on radiation-tolerant microorganisms capable of cryptobiosis. Additionally, we discuss planetary protection concerns and other ethical considerations of sending life to the stars.”
Researchers are thinking about the NASA Starlight program in a new study titled “The First Interstellar Astronauts Will Not Be Human,” to be published in Acta Astronautica in January 2022. Starlight, also known as the Directed Energy Propulsion for Interstellar Exploration (DEEP-IN) and Directed Energy Interstellar Studies (DIES), is one of a number of programs considering how to send small, even micro-small, spacecraft to other star systems. According to Universe Today, this study – conducted by UC Santa Barbara, the UCLA Health Center, the University of Florida, and Ruhr-University Bochum – focused not on how to propel the craft but what kind of microorganisms would make good astronauts … and whether the idea is safe and ethical.
“Tardigrade species are adversely affected by hypergravity but are more resistant than larger organisms, such as the fruit fly, D. melanogaster, while species like C. elegans fare quite well under hyperacceleration. However, tardigrades can be launched in a cryptobiotic state, with the hope that this will mitigate deleterious acceleration-dependent effects of hypergravity on their survival rate.”
Because they can survive in conditions with extreme temperatures, extreme pressures, radiation, dehydration and starvation, tardigrades have already been flown into space, left exposed to the extremes, and still brought back alive able to reproduce. They’ve already been sent to the Moon -- an Israeli mission carrying thousand of dehydrated tardigrades crashed but could conceivably have survived.
If we can send tardigrades to other stars, could extraterrestrial civilizations have already done the same thing – sending them to Earth millions of years ago? That theory has been bandied about by the panspermia crowd, especially after traces of biotic material were found on 4.1 billion year old rocks in Western Australia that may have been asteroids. Whether they were propelled into space intentionally by an advanced civilization or unintentionally on space rocks, their chances of survival, especially if they were dehydrated or in some other suspended state, would be as good as the researchers in the new study believe Earth tardigrades are.
“However, once initial exploratory phases have been completed and best efforts at gathering knowledge of exoplanets has been performed, there may be certain circumstances in which intentionally “seeding life” would not be unethical.”
The study considers sending Earth organisms to other star systems ethical under certain circumstances yet to be determined. However, if the tardigrades were already sent here by ETs, we’re just pulling a “they did it first” switch. The biggest challenge to Starlight and programs like it are the propulsion mechanism needed to send the micro ships at extreme speeds far beyond those of current rockets and spacecrafts. Light sails pushed by lasers are a leading candidate and the study hints that the technology is close to happening.
Should the tardigrades look forward to the beginning of a new adventure … or just the next phase of a previous one?