As a species, we’ve always been marked by curiosity.
Our desire to explore the unknown took us from settlements on long journeys across the continents and oceans into the deepest recesses of the world and to the highest peaks. Even then, a never-ending urge to learn and discover the world wasn’t sated. In modern days it has lured us away from Earth and into uncharted territory among the stars. There, we hope to find a new home for ourselves, and perhaps, even new forms of life.
Although we went to the moon and plan to go to Mars, we still haven’t found alien life — but it’s not for the lack of trying. We’re sending probes, taking snapshots of the universe with ultra-powerful telescopes and analyzing soil samples. Elon Musk of Tesla and SpaceX famously wants interplanetary life on Earth and Mars.
But it seems like we’re looking for a needle in a space haystack, or perhaps there really is no life in the universe, aside from what can be found here on Earth.
If the latter is the case, why don’t we do something about it? Why don’t we seed the cosmos with the Earth’s life forms? That process, known as directed panspermia, or the Genesis Project, is something Claudius Gros, a theoretical physicist at Goethe University in Frankfurt, Germany, says should be more important than colonizing the universe.
Gros also believes our modern technology is more than capable of the feat. In his study published in the Journal of Physics Communications, he proposes to launch a 1.5-ton spacecraft accelerated to 30 percent of the speed of light at an exoplanet devoid of life, but theoretically capable of sustaining it.
Currently, Trappist-1, a planetary system consisting of seven planets that might contain water, is a likely candidate (although some scientists are skeptical), with other exoplanets also being considered as possible substitutes.
Gros’ spacecraft would accelerate in a very special way, similar to what Stephen Hawking has imagined for the tiny Breakthrough Starshot. The vehicle would use a laser-propulsion system. Large, Earth-based lasers would fire at 31-mile-wide photon sails attached to the spacecraft. The acceleration would be the result of the momentum of photons hitting the sail and propelling it forward.
Although 30 percent of the speed of light sounds fast, it would still take the starship some 12,000 years to reach its destination, because of the deceleration mechanism necessary for the vehicle to slow down and assume the orbit around the candidate planet. This can be achieved either by using a magnetic, photon or electric sail.
In the first case, a static magnetic field generated by the sail would deflect charged particles radiated by the star and the imparted momentum would decelerate the craft. Photon sails would be used in reverse orientation, thus using photon particles coming from the target star to decelerate, while electric sails would use the dynamic pressure from the solar wind for the same purpose. Any of these systems would need to be dozens of miles in diameter to provide sufficient deceleration.
Let’s say the mission is successful, 12,000 years have passed and the 1.5-ton starship, outfitted with mini-labs growing genes and cells, has reached its destination, and is orbiting a candidate world. Now comes the seeding. The starship would release clouds of microbial life forms, bacteria and unicellular eukaryotes into the planet’s atmosphere, mimicking conditions on Earth before the Cambrian explosion. This would theoretically allow the organisms to inhabit their new home planet and possibly flourish.
Although no one reading this would be alive to witness the results, I can’t help but wonder if there isn’t a better way to invest our time and energy than bringing life to lifeless planets. What happens if there already is alien life on those planets, and our “domestic” life forms affect it?
Gros disagrees. He believes that his would be a low-cost project and that we shouldn’t dedicate 100 percent of our efforts on humanity-centric research. Ninety-nine percent is enough, and the remaining 1 percent could be used for projects such as his, he argues.
As far as alien life on the candidate planets is concerned, Gros is adamant that there isn’t any.
“If some of the seven Trappist-1 planets still have an ocean, they would also have a massive oxygen atmosphere. Earth’s oxygen pressure is 0.2 bars, but on Trappist-1-like planets, it could be 100 bars or more,” he said. As a result, this excess oxygen would have eaten up any biotic life on these planets, leaving them blank slates, ready for Earth-born organisms.