Panspermia is an interesting theory, but for folks searching for the origins of life, it really doesn't explain anything.
Back in the Dark Ages, when I was an over-aged university student, I took a course titled "the Origins and Evolution of Life". It was under the biology curriculum, but was team-taught by a biologist and a physicist. It covered a lot of topics, such as "punctuated equilibrium" and the Cambrian explosion. Other things studied in the course included a fascinating theory that life originated in clay, and came about because organic molecules adhering to the clays randomly organized themselves according to the crystalline structures in the clay, then some magic happened, and POOF! life. Not much difference from Creationism (God happened, and POOF! life) or the Big Bang theory (again, magic happened, and POOF! a universe). Science does that a loot - to avoid blaming a god for anything, they just replace deities with "magic" and "POOF!"
Anyhow, Panspermia was also touched upon in that course... but as it turns out, it doesn't really explain anything relating to either the origins or the evolution of life. All it does is kick the can down the road. What it effectively says is "since we don't know how life originated, we're just going to say it started elsewhere and was delivered here, and hope no one notices that spontaneous generation of life elsewhere is just as problematic as the spontaneous generation of life right here. - we're just moving the locality of creation."
While it's true that the biological building blocks of life and amino acids are seeded all through space, so far no one in the scientific field has come up with a plausible theory as to how those molecules cane to organize themselves and spark off a life. It's one thing to have a fistful of molecules, and something else altogether to have a fistful of molecules biologically organized and able to self-replicate other organisms of it's own kind, which is a generally accepted definition of "life", or at least it was back then.
One problem with randomly-seeded life during the late bombardment period mentioned in the video is that most all of those bombarding asteroids were from the same soup that created the Earth, so it's no more likely to claim life came from them than to say it just spontaneously generated itself right here. They all came out of the same molecular cloud at the same time.
That does not mean, however, that a single meteoroid could not have traveled through space for millions or billions of years bearing life seeds, and gotten mixed into the fray that was the late bombardment period. I reckon that's a possibility, and it only takes one landing and dispersing a few bacteria to, over time, seed the whole planet with them as they reproduce. It does mean, however, that said bacteria would have to somehow be able to survive millions or billions of years traveling through space, and even then they would have also had to have had an origin... somewhere.
That brings us to the supposed age of the universe - current theory places the age of the universe since the Big Bang postulated event at 13.8 billion years. The solar system is 4.7 billion years old, meaning that it's around 1/3 as old as the entire universe. so, life would have to had originated and developed elsewhere, then spent at least a few millions of years traveling after some disaster at it's origin point ejected it into space, in order to get here. Given that all of the more complex molecules originated in the centers of early stars, and were not dispersed until they had time to age and explode, that puts even further time constraints on the event. ALL elements heavier than hydrogen had to wait for that first generation of stars to start exploding before they could be dispersed, and even have a hope of organizing into more complex molecules, which also took some time.
Most theories of the origin of life say that the sun was among the earliest generations of stars capable - having a sufficient concentration of "metallic" elements ("metallic" elements are all elements heavier that hydrogen) - to give rise to life. So, if that is the case, how could life have originated elsewhere in time to have been send here to seed life on Earth?
So, panspermia, in addition to kicking the can down the road, would appear to raise more questions than it answers.
.
Back in the Dark Ages, when I was an over-aged university student, I took a course titled "the Origins and Evolution of Life". It was under the biology curriculum, but was team-taught by a biologist and a physicist. It covered a lot of topics, such as "punctuated equilibrium" and the Cambrian explosion. Other things studied in the course included a fascinating theory that life originated in clay, and came about because organic molecules adhering to the clays randomly organized themselves according to the crystalline structures in the clay, then some magic happened, and POOF! life. Not much difference from Creationism (God happened, and POOF! life) or the Big Bang theory (again, magic happened, and POOF! a universe). Science does that a loot - to avoid blaming a god for anything, they just replace deities with "magic" and "POOF!"
Anyhow, Panspermia was also touched upon in that course... but as it turns out, it doesn't really explain anything relating to either the origins or the evolution of life. All it does is kick the can down the road. What it effectively says is "since we don't know how life originated, we're just going to say it started elsewhere and was delivered here, and hope no one notices that spontaneous generation of life elsewhere is just as problematic as the spontaneous generation of life right here. - we're just moving the locality of creation."
While it's true that the biological building blocks of life and amino acids are seeded all through space, so far no one in the scientific field has come up with a plausible theory as to how those molecules cane to organize themselves and spark off a life. It's one thing to have a fistful of molecules, and something else altogether to have a fistful of molecules biologically organized and able to self-replicate other organisms of it's own kind, which is a generally accepted definition of "life", or at least it was back then.
One problem with randomly-seeded life during the late bombardment period mentioned in the video is that most all of those bombarding asteroids were from the same soup that created the Earth, so it's no more likely to claim life came from them than to say it just spontaneously generated itself right here. They all came out of the same molecular cloud at the same time.
That does not mean, however, that a single meteoroid could not have traveled through space for millions or billions of years bearing life seeds, and gotten mixed into the fray that was the late bombardment period. I reckon that's a possibility, and it only takes one landing and dispersing a few bacteria to, over time, seed the whole planet with them as they reproduce. It does mean, however, that said bacteria would have to somehow be able to survive millions or billions of years traveling through space, and even then they would have also had to have had an origin... somewhere.
That brings us to the supposed age of the universe - current theory places the age of the universe since the Big Bang postulated event at 13.8 billion years. The solar system is 4.7 billion years old, meaning that it's around 1/3 as old as the entire universe. so, life would have to had originated and developed elsewhere, then spent at least a few millions of years traveling after some disaster at it's origin point ejected it into space, in order to get here. Given that all of the more complex molecules originated in the centers of early stars, and were not dispersed until they had time to age and explode, that puts even further time constraints on the event. ALL elements heavier than hydrogen had to wait for that first generation of stars to start exploding before they could be dispersed, and even have a hope of organizing into more complex molecules, which also took some time.
Most theories of the origin of life say that the sun was among the earliest generations of stars capable - having a sufficient concentration of "metallic" elements ("metallic" elements are all elements heavier that hydrogen) - to give rise to life. So, if that is the case, how could life have originated elsewhere in time to have been send here to seed life on Earth?
So, panspermia, in addition to kicking the can down the road, would appear to raise more questions than it answers.
.