Original paper: https://www.science.org/doi/10.1126/sciadv.adw1280
Earth was born dry until a cosmic collision made it a blue planet
11–20 of 279 posts
Re: Earth was born dry until a cosmic collision made it a blue planet
#12All life on Earth is illegal immigrants from another planet.
Only if the earth was seeded with life.
Which is possible, at least from sites elsewhere in the young solar system. Life might have originated on Mars, for example, or perhaps in one of many small, warm, wet asteroids. These early asteroids were kept from freezing up by the presence of short lived radioisotopes, the decay products of which are detectable today in parts of meteorites.
Re: Earth was born dry until a cosmic collision made it a blue planet
#13[flagged]
Re: Earth was born dry until a cosmic collision made it a blue planet
#14How does this square with the fact that we have solid evidence of water on Mars as well?
Having some water and having lots of water is a slight difference. The most arid dessert on earth is a jungle compared to Mars. (Also Mars could have been also hit.)
Except Titan likely has more water on it than Earth. Therefore unless we’re a fluke of a solar system planetary bodies with water on them should be extremely common.
Re: Earth was born dry until a cosmic collision made it a blue planet
#15This could mean in the Drake equation ne -number of planets capable of life- is very small. A planet has to be hit with a comet big enough to deliver a large amount of water but not so big or fast to destroy it. And be in the Goldilocks zone of the star. Also the mass of the planet would play a part - gravity of more massive ones would be more likely to capture a comet. But again, too massive and I could see that ham…
Unless collisions like the article suggests are a statistical inevitability, that is.
Right, that's the sticky point? The likelihood of a planet in the Goldilocks zone to be too hot in the early stage of stabilizing its chemistry that it requires seeding with "post-formation" chemistry? Is that likelihood close to 100%, or maybe not even near and we were just set up for a funny cosmic event.
Re: Earth was born dry until a cosmic collision made it a blue planet
#16Ah the First Impact
I know this reference lol
Re: Earth was born dry until a cosmic collision made it a blue planet
#17All life on Earth is illegal immigrants from another planet.
Only if the earth was seeded with life.
Which seems to be quite possible. This is what we have from just one mission: https://www.esa.int/Science_Exploration/Space_Science/Rosett...
Re: Earth was born dry until a cosmic collision made it a blue planet
#18This could mean in the Drake equation ne -number of planets capable of life- is very small. A planet has to be hit with a comet big enough to deliver a large amount of water but not so big or fast to destroy it. And be in the Goldilocks zone of the star. Also the mass of the planet would play a part - gravity of more massive ones would be more likely to capture a comet. But again, too massive and I could see that ham…
Your assumption we need water for life to exist is in my opinion wrong. We only know Earth so assume that is what is needed for life to exist.
Re: Earth was born dry until a cosmic collision made it a blue planet
#19This could mean in the Drake equation ne -number of planets capable of life- is very small. A planet has to be hit with a comet big enough to deliver a large amount of water but not so big or fast to destroy it. And be in the Goldilocks zone of the star. Also the mass of the planet would play a part - gravity of more massive ones would be more likely to capture a comet. But again, too massive and I could see that ham…
No kidding... This would probably resolve the Fermi paradox if proven true...
Re: Earth was born dry until a cosmic collision made it a blue planet
#20This could mean in the Drake equation ne -number of planets capable of life- is very small. A planet has to be hit with a comet big enough to deliver a large amount of water but not so big or fast to destroy it. And be in the Goldilocks zone of the star. Also the mass of the planet would play a part - gravity of more massive ones would be more likely to capture a comet. But again, too massive and I could see that ham…
Your assumption we need water for life to exist is in my opinion wrong. We only know Earth so assume that is what is needed for life to exist.
What's the chemistry of life without water? Do you refer to the promising Russian studies of life sustained by alcohol?