> WASP-127b, a giant gas planet located more than 500 light-years from Earth. How do you define "sound speed" on a gas giant?
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Extreme supersonic winds measured on a planet outside our solar system
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Re: Extreme supersonic winds measured on a planet outside our solar system
#12> WASP-127b, a giant gas planet located more than 500 light-years from Earth. How do you define "sound speed" on a gas giant?
You can simulate the speed of sound based on atmospheric makeup and temperature. That said, 9 km/s is probably going to be supersonic in most media (for reference, the speed of sound in most metals is several km/s).
Re: Extreme supersonic winds measured on a planet outside our solar system
#13Woah how’s that even possible? How does the fluid pick up so much kinetic energy? I’m not saying they’re wrong, I’m just fascinated.
Possibly solar radiation?
Re: Extreme supersonic winds measured on a planet outside our solar system
#14> WASP-127b, a giant gas planet located more than 500 light-years from Earth. How do you define "sound speed" on a gas giant?
As a layperson I thought that was odd choice too and would be an Earth-centric measurement, but the paper on which this article is based references this paper: https://iopscience.iop.org/article/10.3847/1538-3881/ac51d2
Where they spell out a formula for the speed of sound in this type of planet given some assumptions. It's beyond my understanding, but I thought it was pretty cool. Section 4.4 if you want to have a look.
Then back to the article paper: https://www.aanda.org/articles/aa/full_html/2025/01/aa50438-...
> Using their formula we obtain sound speeds of the order of 3 km s−1 for WASP-127 b.
Re: Extreme supersonic winds measured on a planet outside our solar system
#15Wow, that's 9km/s. In comparison, objects in Low Earth Orbit travel around 8km/s.
Re: Extreme supersonic winds measured on a planet outside our solar system
#16Woah how’s that even possible? How does the fluid pick up so much kinetic energy? I’m not saying they’re wrong, I’m just fascinated.
The gas is probably mostly hydrogen. Hydrogen accelerated through a thermal rocket can reach 10 km/s or more.
Re: Extreme supersonic winds measured on a planet outside our solar system
#17Not an original thought, but I wonder if the answer - or part of it - to the Fermi paradox is that we don't know all the ways it's possible for a planet in the Goldilocks Zone to be otherwise hostile to life. Liquid water and.. chemistry leading to an ambient pH of 2 or 12. Liquid water and.. radiation environment such that proto-RNA strands get immediately smashed to bits by high-energy rays. Liquid water and.. bomb…
But there are also 7500 known exoplanets within a few tens of thousands of light years of Earth. There are almost certainly multiples more than that we cannot see.
The "Goldilocks Zone" is also highly anthropomorphised: there are extremophiles that live in all sorts of crazy environments on Earth.
I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
Re: Extreme supersonic winds measured on a planet outside our solar system
#18Not an original thought, but I wonder if the answer - or part of it - to the Fermi paradox is that we don't know all the ways it's possible for a planet in the Goldilocks Zone to be otherwise hostile to life. Liquid water and.. chemistry leading to an ambient pH of 2 or 12. Liquid water and.. radiation environment such that proto-RNA strands get immediately smashed to bits by high-energy rays. Liquid water and.. bomb…
But there are also 7500 known exoplanets within a few tens of thousands of light years of Earth. There are almost certainly multiples more than that we cannot see. The "Goldilocks Zone" is also highly anthropomorphised: there are extremophiles that live in all sorts of crazy environments on Earth. I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
Extremophiles don't tend towards complexity, though.
And if each common variable has, say, a 10% range in which complex life can occur, you don't need that many to start reducing probability a lot.
- Orbital stability? - Tidal and seasonal ranges? - Magnetic fields?
- And the big one - properties of our Sun & solar system that make it different to others of a similar age? For example, are there galactic-scale properties that affect the surface environment of planets on a long enough time-scale, so that, just as Earth exists in the habitable zone of our Solar System, there is a relatively narrow galactic habitable zone?
All the more reason though to get some telescopes built that can glean more detailed information on exoplanets. We might be in for another shock like the Mariner probes, or it might be 180 degrees the opposite.
Re: Extreme supersonic winds measured on a planet outside our solar system
#19Not an original thought, but I wonder if the answer - or part of it - to the Fermi paradox is that we don't know all the ways it's possible for a planet in the Goldilocks Zone to be otherwise hostile to life. Liquid water and.. chemistry leading to an ambient pH of 2 or 12. Liquid water and.. radiation environment such that proto-RNA strands get immediately smashed to bits by high-energy rays. Liquid water and.. bomb…
But there are also 7500 known exoplanets within a few tens of thousands of light years of Earth. There are almost certainly multiples more than that we cannot see. The "Goldilocks Zone" is also highly anthropomorphised: there are extremophiles that live in all sorts of crazy environments on Earth. I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
> I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
If you're silent with the intent of remaining hidden, then that behavior must have been learned. Either you evolved from a prey type of species, or a non-apex predator.
It would be strange of humanity is the only apex-ish predator intelligent-ish life form in the universe that blasts signals into space without consideration of who might hear them.
Re: Extreme supersonic winds measured on a planet outside our solar system
#20> Reaching speeds up to 33,000 km/h, the winds make up the fastest jet stream of its kind ever measured on a planet.
Great planet for sailing!