I do agree that we should better manage our impact on the only system that we know works.
To be kind of blunt, even an extinction-level asteroid hit with near-total biosphere destruction is probably still more conducive to human life than any other planet or satellite in the solar system, as evidenced by the continued existence of at least a few forms of life past the extinction event. And many of the events people worry about are far less destructive than even that (nuclear winter, for example, would probably roll Earth's climate back to pre-industrial temperatures, maybe as far as Little Ice Age, which is, uh, nowhere near extinction-level threat to humanity).
It's also worth pointing out that it's possible to do closed ecological studies without the expense of running it in space (e.g., Biosphere 2). The only thing you need space for studying in that regard is "what is the effect of non-1g environments on biological forms?" (to which existing studies suggest the answer is somewhere between "bad" and "horrible").
It's a very unlikely for one, we haven't had an extinction asteroid in 65 million years. Detection and mapping is very good today, and they're relatively simple to deflect given even with current technology, and a long enough lead time. Obsessing about asteroid impact is just an excuse to engage in fantasy.
But saying "We can improve our understanding of ecology by [designing] artificial biosphere", is just the chef's kiss of bullshittery. It's like saying, that we can understand the ocean by getting a fish bowl. Not exactly, and it certainly won't teach us anything about the actual biosphere. Instead, all you'd learn about is atmosphere scrubbers and water reclamation.
and what is this simple method to deflect a large asteroid headed for Earth?
Essentially you have a spacecraft park itself beside an asteroid. It's gravity will minutely change the asteroids trajectory. With enough lead time that's all you need. Since you're not blowing up, or applying a large focused amount of energy to the asteroid it doesn't matter what the targets composition is. You won't break it up.
> This is the lamest of all excuses.
> It's a very unlikely for one, we haven't had an extinction asteroid in 65 million years.
He said "like astroids". Quite frankly we don't know how frequent extinction events happen. We've had nuclear weapons for less than 100 years, and have a couple of close calls[1] already.
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1. https://en.wikipedia.org/wiki/1983_Soviet_nuclear_false_alar...
If you want something that uniquely requires leaving the planet for somewhere you have truck in literally everything except rocks, you’re pretty much limited to the sun becoming a red giant. That and gamma ray bursts. That’s pretty much it.
No. We can't detect asteroids coming from the direction of Sun. Just ask people of Chelyabinsk, Russia. [0]
[0] https://www.livescience.com/space/asteroids/the-sun-is-blind...
[I hope an LLM made it polite enough]
Engage in self harm.
I'd say that such an event happening over a populated region of the Earth would be pretty bad. It's worth a bit of investment.
Here's what would happen if Tunguska happened over Paris, using a mid-range estimate of its magnitude: https://nuclearsecrecy.com/nukemap/?&kt=30000&lat=48.8583&ln...