I'm not ssure it's ethical to deliberately send organisms to a distant planet. A novel organism can destroy all other life on a planet; it happened here.
Spreading living organisms far beyond our solar system is clearly a bad idea at this stage of development and knowledge. We could easily destroy other ecosystems. Imagine how we'd feel if the opposite happened. Of course anyone who pays attention knows that we have discovered all the precursors of life, the 4 genetic bases (one of them is different between rna and dna so there are kind of 5 but they found that 5th one too) - we've already detected them in space, which is amazing in itself. It's extremely likely there will be other places in the universe, almost certain based on the number of galaxies and stars, that other planets have life on them. We can't just dump a bunch of developed microbes there that might have unknown effects.
I think in a few years we'll find some kinds of microbes on mars or other bodies. If nothing else they came from earth, floating around, but more probably they are created everywhere naturally by dna molecules just randomly combining. Anyway, when we find life on mars, or Europe or where-ever, should we not allow people to send earth based microbes to do things. We could send lichen to mars to start growing, maybe it would survive and it might kill native microbes. Is that okay? I think it's not but it's pretty complicated and maybe inevitable. Also I think with meteors hitting mars they are probably knocking bits of dust into the air and eventually they hit here. Same for earth to mars but our atmosphere blocks them.
I don't even know if you could detect a difference between an extrasolar high-velocity (60,000 km/s) low-mass (10^-2 kg) airburst and an interplanetary 'low'-velocity (27 km/s) high-mass (10^+9 kg) airburst.
Importantly, these events are purely thermal, not nuclear, so there would be no radioactive fallout.
And it caused broken windows, other damage, over 1000 injuries.
This would be 10x larger?
To be fair, if that meteor had hit over a big city, it would have caused much more damage. More probable if it had hit over open ocean, it would have done very little.
This probe crashing in to a planet that any life form cares about would be extremely unlikely.
Well, no. Straight down is possible, but not necessary or even necessarily likely.
I think there's relatively little empirical evidence with respect to relativistic collisions at macroscopic scales, but isn't there a simpler conservation of energy argument to be made? Absent fancy orbital mechanics maneuvers, isn't the upper bound of the 'planet killing' energy of impact the total energy imparted by the accelerating lasers?
Or am I missing something (could be physics was 30+ years ago.)
The energy of a 10g object at 0.2c is not just bounded, it is calculatable, and not really that large. The earth has had worse encounters, multiple times, in the last century. The above wildly overstates even a "best case straight down direct hit" scenario.
I did misspeak I said "straight down", that's not necessarily true. Could be along a diagonal at any angle.
With respect, I think that _is exactly_ how a meteor works.
So the extreme velocity times smaller mass gives us a middling kinetic energy. The difference, the extreme velocity, means that the energy is burned up as the object disintegrates into atoms over milliseconds not seconds as a regular meteor with the same energy would. Atoms and small fragments won't sustain their velocity.
There's a fast bright flash of superheated air, a clap of thunder as the trail collapses, done.
Respect to you as well!
https://news.ycombinator.com/item?id=33177030
"Straight down" is odds against. Over a place that's not empty land or water is also odds against.
Do you have any reason to believe C. elegans or tardigrades will behave differently in the vicinity of Alpha Centauri? Wouldn't that mass be better used doing just about anything else?
It’s weird that NASA is funding the DEEP-IN part of the project but not the microbe part. IMO you cannot separate the two.
The probability that some earth bacteria would outcompete the local fauna on a planet it was not evolved for seems impossible to know.
But my guess is very close to 0.
When cyanobacteria evolved, they filled the world with molecular oxygen, which was toxic to most of the other organisms on Earth. The cyanobacteria could cope with the O2; so effectively, they terraformed the Earth into a place they could live, at the expense of the organisms that were doing very nicely, thank you, until the cyanobacteria turned up.
I don't believe that life travels between stars.
It can't happen by accident; it has to be done by a sophisticated civilisation. The only evidence I have of such a civilisation is ours, and it's only been able to launch space rockets for a few decades. And our civilisation was living in caves just a few millennia ago. I have no reason to believe we are more than a flash in the pan. I feel sure that in a few more millennia, if we're still around, we won't be interested in interstellar probes we fired-off in antiquity.
Most, not all were either wiped out or survive only in small anaerobic niches. It was a mass extinction.
I'm sort-of OK with the idea that life travels through space as fungus spores, or something like that. I'm not OK with the idea that they are "sent". So I can believe that life on Earth "fell from the sky". But I don't think that's really what happened.
Not impacting and sailing off into the dark for a few megayears is slower but also effective.