Evidence is accumulating in the direction of Mars having once been habitable, and if strong evidence for life on Mars emerged, I would interpret this as strong evidence for the above model.
I’m not familiar with the evidence you’re referring to, but on general principles… if we get evidence that Mars used to be habitable, but we don’t get evidence that it used to be actually inhabited, isn’t that evidence against your scenario?
Evidence for your scenario would be either evidence that Mars used to be inhabited, like you say; or that it was never habitable, giving another explanation for the lack of evidence that it was inhabited.
Yes, I didn’t structure that part very well. My general point was that evidenceisaccumulating in the direction of Mars having had life during the Noachian period. Not a strong signal (as the evidence isn’t there yet), but a weak signal in favour of the stellar nursery model alongside strong evidence for molecular panspermia. You are quite right that a habitable but uninhabited Mars would be weak evidence against panspermia.
I’m not familiar with the evidence you’re referring to, but on general principles… if we get evidence that Mars used to be habitable, but we don’t get evidence that it used to be actually inhabited, isn’t that evidence against your scenario?
Evidence for your scenario would be either evidence that Mars used to be inhabited, like you say; or that it was never habitable, giving another explanation for the lack of evidence that it was inhabited.
Yes, I didn’t structure that part very well. My general point was that evidence is accumulating in the direction of Mars having had life during the Noachian period. Not a strong signal (as the evidence isn’t there yet), but a weak signal in favour of the stellar nursery model alongside strong evidence for molecular panspermia. You are quite right that a habitable but uninhabited Mars would be weak evidence against panspermia.