Do you think any aliens exist in the universe?

[pood]

If speculative silicon life forms existed, for example, I imagine to us they would be like living rocks, and nobody wants to eat a rock.

Such life would be no more like living rock than we are like living diamonds.

Good point. I wonder what they would be like?

 

[bilby]

If speculative silicon life forms existed, for example, I imagine to us they would be like living rocks, and nobody wants to eat a rock.

Such life would be no more like living rock than we are like living diamonds.

Good point. I wonder what they would be like?

 

[Shadowy Man]

Scientists have dated the last universal common ancestor all the way back to 4.2 billion years, and say it was already surprisingly similar to modern bacteria. The implication here is that life may rather easily arise and quickly evolve, suggesting there is planety of it in the universe.

At least in this solar system. We know from direct observations in our galactic neighborhood that earthlike planets around sun-like stars are rare, unless we badly overestimate our ability to detect them.

I'm not an expert on exoplanets, but I believe there are still strong observational biases against discovering Earth-sized planets, so I don't think we can make a definitive statement about the rarity of Earth-like planets.

I'm not an expert in abiogenesis either, but I can imagine that we also cannot make a clear statement as to whether having an Earth-like planet is necessary for the formation of life.

 

[pood]

I'm not an expert in abiogenesis either, but I can imagine that we also cannot make a clear statement as to whether having an Earth-like planet is necessary for the formation of life.

When life formed on earth it wasn’t remotely earth-like either, compared to what the earth is now.

 

[Elixir]

we also cannot make a clear statement as to whether having an Earth-like planet is necessary for the formation of life.

I have nothing to lose by positing that life exists almost everywhere there are relatively stable, moderated temperatures and water.
At least I can safely expect to not be disabused of that belief any time soon.

 

[Shadowy Man]

I'm not an expert in abiogenesis either, but I can imagine that we also cannot make a clear statement as to whether having an Earth-like planet is necessary for the formation of life.

When life formed on earth it wasn’t remotely earth-like either, compared to what the earth is now.

By “earth-like” it is typically meant earth mass and in habitable zone of star, not atmospheric or geologic state. At least in the exoplanet detection business.

 

[thebeave]

If speculative silicon life forms existed, for example, I imagine to us they would be like living rocks, and nobody wants to eat a rock.

Such life would be no more like living rock than we are like living diamonds.

Good point. I wonder what they would be like?

Like this, maybe?

 

[Elixir]

I'm not an expert in abiogenesis either, but I can imagine that we also cannot make a clear statement as to whether having an Earth-like planet is necessary for the formation of life.

When life formed on earth it wasn’t remotely earth-like either, compared to what the earth is now.

By “earth-like” it is typically meant earth mass and in habitable zone of star, not atmospheric or geologic state. At least in the exoplanet detection business.

Our earth will probably not remain earthlike for much longer, cosmologically speaking.

 

[aupmanyav]

Our earth will probably not remain earthlike for much longer, cosmologically speaking.

Perhaps we have about a billion years before the sun roasts the earthlings.

 

[DBT]

Our earth will probably not remain earthlike for much longer, cosmologically speaking.

Perhaps we have about a billion years before the sun roasts the earthlings.

Some estimate far less, not that the earth will roast, but perhaps become too hot to sustain a civilization, or with rising CO2 and a runaway greenhouse effect, the earth becomes another Venus.

 

[Shadowy Man]

Our earth will probably not remain earthlike for much longer, cosmologically speaking.

Perhaps we have about a billion years before the sun roasts the earthlings.

How did you come to that figure?

 

[Elixir]

Our earth will probably not remain earthlike for much longer, cosmologically speaking.

Perhaps we have about a billion years before the sun roasts the earthlings.

…so its hospitable-to-life lifespan is like, over 80% spent?
That’s kinda how I feel lately. Maybe not 4 billion years old, but at least a billion or two.

 

[steve_bank]

According to current scientific understanding, Earth is likely to become uninhabitable due to the Sun's natural evolution within roughly 1 billion years, as the Sun will gradually grow brighter, making Earth too hot to sustain life as we know it; although the Sun itself won't "die" for another 5 billion years or so, Earth will be engulfed by the Sun when it enters its red giant phase.

The Sun's death could mean new life in the outer solar system

What will happen to the solar system when the Sun dies? It might be the end of planet Earth, but life could still find a way.

www.astronomy.com

The slow death will kill off life on Earth, but it may also create habitable worlds in what’s currently the coldest reaches of the solar system.

Any humans left around might find refuge on Pluto and other distant dwarf planets out in the Kuiper Belt, a region past Neptune packed with icy space rocks. As our Sun expands, these worlds will suddenly find themselves with the conditions necessary for the evolution of life.

These are the “delayed gratification habitable worlds,” says planetary scientist Alan Stern of the Southwest Research Institute.

“Late in the life of the Sun — in the red giant phase — the Kuiper Belt will be a metaphorical Miami Beach,” Stern says.

Let’s take a quick jaunt through our solar system in the last days of the Sun.

 

[Elixir]

When the ice melts on Enceladus, the fishing is going to be fantastic.

 

[Shadowy Man]

This paper (https://arxiv.org/abs/2409.10714) suggests the lifetime of the terrestrial biosphere may be as high as 1.86 Gyr. But it seems this an active area of atmospheric research.

​

 

[Shadowy Man]

When the ice melts on Enceladus, the fishing is going to be fantastic.

I know of some people from Wisconsin that only need to wait for the ice to thin to go fishing .

 

[bilby]

When the ice melts on Enceladus, the fishing is going to be fantastic.

I know of some people from Wisconsin that only need to wait for the ice to thin to go fishing .

The ice at Enceladus's south pole may be as little as a kilometer thick. What are they waiting for?

 

[steve_bank]

Think of the real estate development opportunities.

 

[aupmanyav]

Trump Towers.

 

[bilby]

Enceladus - The Greenland of the Outer Solar System.