In all the observed universe, of all the magnificent wonders of the universe, even of the hundreds of extrasolar planets catalogued over the past two decades, only Earth is known to harbor life as we know it. But that’s all we need to ask some very interesting questions about life. To begin, is life here a result of spontaneity? Were we an accident of nature? Or is life more ubiquitous than that? When we read some hard science fiction of the twentieth century, readers may wonder, if our solar system is truly floating through the dusty remains of ancient, glorious empires and civilizations, how would we know?
HARVARD ASTROPHYSICISTS TO TRACK INTERSTELLAR LIFE
Recent research by Harvard astrophysicists haven’t answered the question of biogenesis, however, they have shown a necessary trace that ought to be present in interstellar space (known as panspermia); an identifiable pattern that we on Earth could possibly observe.
“In our theory, clusters of life-form grow and overlap like bubbles in a pot of boiling water,” said henry Lin of the Harvard-Smithsonian Center of Astrophysics (CfA).
HOW CAN LIFE ESCAPE ITS HOME STAR?
When it comes to interstellar travel, there are two known ways for life to travel beyond the reach of its parent star. One is via one of the several physical processes of interacting bodies, e.g., gravitational slingshotting of comets and asteroids bearing the organic molecules needed for more complex life forms. Another way is for an already developed intelligent life form to make some sort of exodus from their home planet, somehow driven into interstellar space. The Harvard astrophysicists research doesn’t actually account for panspermia; instead it wants to know if we could detect such an exodus, if it were to happen?
Their findings have provided a resounding “yes” for an answer.
EXPERIMENTAL CONTROLS AND ASSUMPTIONS
A few assumptions were made, though. For instance, until an interstellar species finds a neighboring planet capable of harboring life, their exodus is a diaspora, i.e., they travel outwards in all directions three dimensions allows. Once they discover a nice new home, they can take root, form trade lines, and begin to form interstellar strands of life. On a long enough timeline, this process would develop a series of life-bearing oases littering the night sky, which we would in theory be able to eventually observe.
“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,” explained Avi Loweb from the CfA.
WHAT WILL WE DO ONCE WE’VE DETECTED ALIEN SPACE TRAVEL?
The first step after discovering signs of life in alien worlds will be to look for such patterns of interstellar expansion and civilization. Lin and Loeb are cautious, and encourage us to do the same because a pattern would only be obvious if the species under question spread very rapidly. Moreover, the effect of redshift as a result of interstellar drift may mean that many civilizations’ light cannot outrun the speed at which their solar systems are moving away from us; hence we would never detect them.
More on this fascinating topic can be read in an original article of op ed intrigue by the Harvard-Smithsonian Center for Astrophysics, at Astronomy Magazine.
