“Panspermia” is a century-old theory in astrophysics hypothesizing that life or the chemical precursors to life spread throughout the Milky Way onboard objects such as asteroids and planetoids. In a new study titled Galactic Panspermia, a pair of scientists suggest Panspermia is applicable not just of a single galaxy or solar system, but the entire universe at large. Let’s take a look at some of the ways Panspermia works.
Gravitational “fishing nets”
Small objects like the recently documented “Oumuamua,” the first ever interstellar object to enter our system, can be captured much like with a net by the gravitational interaction between stars and other stars or planets. Here the gravitational relationship between Jupiter and the Sun acts like a giant fishing net, ensnaring voyaging objects from outside our solar system which may contain life.
Galactic centers act like giant catapults
With the center of the Milky Way playing host to a super-massive black hole, this region of space regularly sees immense gravitational forces which allow for not just the catapulting of small asteroid-sized objects, planetoids, and other debris, but also entire stars called hyper-velocity stars; all capable of carrying life to other solar systems.
More than 100 million possible life-bearing objects have hitchhiked
According to Drs. Idan Ginsberg, Manasvi Lingam, and Abraham Loeb, the brains behind the new study, It’s possible that as many as 100 million objects the size of Enceladus, one of Saturn’s moons, could have left their progenitor system and gone to another. In terms of other smaller-sized objects, the numbers could be far higher, as size and velocity are two of the main factors in the equation.
Stars can leave their own galaxies
As dramatic as cosmic events are, few bring pizzazz like the galactic merger. The new study bolstered the conclusion of another scientist’s work who determined that the beforementioned hyper-velocity stars are products of galactic collisions. These stars have been known to leave their own galaxies during these events and move at a fraction, maybe one third, of lightspeed into seas of stars which sit between galaxies.
Hyper-velocity Stars Bring Their Systems With Them
There are, according to another study, roughly a trillion of these hyper-velocity stars in intergalactic space which have, during galactic mergers, been flung through massive black holes formed during the mergers in a kind of inter-dimensional slingshot. These brave nomads have also been known to bring their planetary systems with them; making these the ultimate specialists of Galactic Panspermia.