Alien life could be all around us (relatively speaking), a new Harvard study suggests, and could very well exist in interstellar clusters, or “pockets of life,” throughout the Milky Way galaxy. Researchers have concluded that the idea behind panspermia, if it should prove to be viable theory, indicates that such areas should be detectable to those searching for the existence of alien life — like human beings here on Earth.
Phys.org reported August 27 that Harvard astrophysicists, led by Henry Lin of the Harvard-Smithsonian Center for Astrophysics (CfA), have established that the theory of panspermia would allow for the detection of alien life in interstellar groupings or clusters. The model developed by researchers noted that life, if found, would be detected in patterns, reaching out from a central location or jump-off point. “In our theory clusters of life form, grow, and overlap like bubbles in a pot of boiling water,” Lin said.
The study posited that life would spread between the stars in two ways from a host star. The first would be via natural physical processes such as gravitational slingshotting of asteroids or comets that carried life-generating molecules. The second process would occur due to intelligent life deliberately expanding their territory outward into interstellar space.
CfA co-author Avi Loeb explained the process: “Life could spread from host star to host star in a pattern similar to the outbreak of an epidemic. In a sense, the Milky Way galaxy would become infected with pockets of life.”
The model works on the assumption that living entities or the building blocks of life would spread omnidirectionally from one host star to other habitable planets circling neighboring stars. These new host planets would, with time, exist as oases within the galactic framework.
The study’s authors note that once alien life is detected, it should be relatively simple to establish a pattern of world’s supporting life. They provided the example of Earth (since it is the only life-bearing planet yet known) as part of such a pattern. If Earth were on the edge of such a panspermian diaspora, other worlds with living organisms would be detectable among stars in just one half of the sky. The other side of the sky would be empty.
The authors cautioned that their working model depended on a relatively quick spreading of living organisms from one host world to another. They explained that life developing at slow rates, given enough time for stellar drift and worlds becoming more distant from each other over vast periods of time (millions of years), those overlapping “bubbles” of interstellar clusters of life could expand and become extended. (Given that life on Earth, according to the current theory of the evolution of life on the planet, began about a billion years after the planet coalesced, and it took another 2.3 or so billion years for modern humans to start marching toward the day they would study the stars and wonder about alien life, this “smearing” of the “bubbles” is an all too possible scenario. In short, finding life among the stars in a discernible pattern could very well have become impossible millions — or even billions — of years ago.)
The paper, which was published in Astrophysical Journal Letters, does not touch on the mechanics of the theory of panspermia itself and its processes. The study’s objective was to discover, if panspermia does occur, could an observer, such as humanity, detect it? In principle, the answer would be yes.
The search for extraterrestrial life, once relegated to organizations like the SETI (Search for ExtraTerrestrial Intelligence) Institute in California, has become a major objective of various programs. In July, astrophysicist Stephen Hawking helped Russian billionaire Yuri Milner launch Breakthrough Initiatives, a $100 million 10-year multi-platformed undertaking to search for alien life. And just last year, NASA for the first time predicted that the search for alien life — but most likely in microbial form and unlikely to be sentient — would result in success within the next 20 years.