by Ann » Tue Aug 08, 2023 2:58 am
zendae1 wrote: ↑Mon Aug 07, 2023 3:48 pm
Would the hydrogen and oxygen combine under the evolving conditions to form water? It is happening within the accretion disc of PDS 70, a very young star very close to the Solar System. Free floating water vapor just sitting there, in the Goldilocks zone. And two proto-planets forming there also, where the water is.
Water isn't rare in the Universe.
Forbes wrote:
In science fiction, when an advanced alien civilization visits Earth, they always want something. Often it's our precious water. Earth is a water-rich world, and (as far as we know) life depends upon water. But water isn't that rare in the cosmos. Water is made of hydrogen and oxygen. Hydrogen is by far the most abundant element, and Oxygen is the third most abundant. Number two is helium, which doesn't react chemically, so water is really common.
...
Recently a team studied the atmospheres of 19 exoplanets. These were large planets like Neptune or Jupiter, rather than smaller, Earth-like worlds. But it is the first survey to see how common water is on exoplanets. The team detected water on 14 of the worlds, which suggests that most exoplanets have water. This is what you would expect, given the molecule's abundance.
But the team also found something rather surprising. While water was often present, it wasn't typically abundant. This was true for a wide range of exoplanets, from hot Jupiters to much cooler worlds. So while water is common in the universe, it may tend to evaporate off planets. That would mean Earth is rather rare.
I would like to add that what sets the Earth apart from so many other planets is not that we have huge amounts of water, because we don't:
No, what makes the Earth so unusual is that our rather small amount of water is liquid and located on our planet's surface. On top of that, the Earth's surface is not completely covered in water, but there is land, too. This may turn out to be very unusual indeed.
Ann
[quote=zendae1 post_id=332803 time=1691423319]
Would the hydrogen and oxygen combine under the evolving conditions to form water? It is happening within the accretion disc of PDS 70, a very young star very close to the Solar System. Free floating water vapor just sitting there, in the Goldilocks zone. And two proto-planets forming there also, where the water is.
[/quote]
Water isn't rare in the Universe.
[quote][url=https://www.forbes.com/sites/briankoberlein/2019/12/13/water-is-common-in-the-universe-but-it-might-not-be-abundant-on-alien-worlds/]Forbes[/url] wrote:
In science fiction, when an advanced alien civilization visits Earth, they always want something. Often it's our precious water. Earth is a water-rich world, and (as far as we know) life depends upon water. But water isn't that rare in the cosmos. Water is made of hydrogen and oxygen. Hydrogen is by far the most abundant element, and Oxygen is the third most abundant. Number two is helium, which doesn't react chemically, so water is really common.
...
Recently a team studied the atmospheres of 19 exoplanets. These were large planets like Neptune or Jupiter, rather than smaller, Earth-like worlds. But it is the first survey to see how common water is on exoplanets. The team detected water on 14 of the worlds, which suggests that most exoplanets have water. This is what you would expect, given the molecule's abundance.
But the team also found something rather surprising. While water was often present, it wasn't typically abundant. This was true for a wide range of exoplanets, from hot Jupiters to much cooler worlds. So while water is common in the universe, it may tend to evaporate off planets. That would mean Earth is rather rare.[/quote]
I would like to add that what sets the Earth apart from so many other planets is not that we have huge amounts of water, because we don't:
[img3=""]https://apod.nasa.gov/apod/image/2209/WaterlessEarth2_woodshole_960.jpg[/img3]
No, what makes the Earth so unusual is that our rather small amount of water is liquid and located on our planet's surface. On top of that, the Earth's surface is not completely covered in water, but there is land, too. This may turn out to be very unusual indeed.
Ann