Yes, good point. There is interesting argument that favors life having begun at ocean vents.
Are you suggesting a grb could have been a real possibility long ago? The Sun likely was part of a cluster of less than 3000 stars, so the IMF favors only a few stars of a massive size. I would guess a life sterilizing grb would be more unlikely than likely. I suspect we could see such a sterilization in ancient rock, especially lunar rocks, but I'm guessing.
Little red dwarfs are fully convective, so nothing spins like a solid would. The Sun spins like a solid, they think, for the core and radiative zones, but convective for the outer zone. The boundary is called the tachocline. I've tended to think this is the place where the seeds for storms begin -- like trailer parks for tornadoes.
But these low mass stars can have a life up to about a trillion years, so a few billion years is long before maturity, whatever that looks like. There should be some older red dwarfs that may exhibit fewer tantrums, or has this been studied already? They are hard to see because they are so dim, so these new giant scopes will offer a great deal more in this area, no doubt. The JWST should help as well given it's longer wavelength advantages.
I have seen descriptions of the early solar system as a pin-ball machine due to all the wild dynamics. The Nice model, IIRC, manages to predict, after wild orbital shifts, all the current planetary orbital locations with the exception of Pluto, so it's not a perfect model.
I'm unsure what you mean by more challenging. Progress for greater capability of discovery is only getting better.
Yes, I recall SGR1806 being brighter than any other object in the galaxy when it went nuts. But, as you show, brighter ones have come since.Yes, I can't quote sources, but there is one of the mass extinctions they can't find evidence of volcanism or iridium from an impactor. GRB was their most probable cause.
Bad thing about GRB is there is no possible way of warning.
GRB221009A last October, brightest GRB ever seen. Disrupted radio transmissions. This, from a distance of 2.4 million light years.
Most powerful gamma-ray burst ever seen could help reveal how black holes are born
"We're just really in awe of this event and feeling very lucky to be able to study it."www.space.com
Helio, you said *I'm unsure what you mean by more challenging*. I am not pointing out discovery methods improving that could make for better observations, but more astronomical constraints appear for habitable exoplanets as time goes by. The 10-page paper made this clear when discussing briefly habitability and so too the space.com article. "This new research suggests unexpectedly intense magnetic fields arise around cool, small stars when the surfaces and interiors of those stars start out by rotating at the same speed but, over time, drift apart and spin out of sync. The team behind the study calls that internal mechanism core-envelope decoupling, a process that could ultimately impact our search for life elsewhere in the Milky Way. "Stellar physics can have surprising implications for other fields," Lyra Cao, team lead and an astronomy graduate student at Ohio State University, said in a statement. "Stars experiencing this enhanced magnetism are likely going to be battering their planets with high-energy radiation. This effect is predicted to last for billions of years on some stars, so it’s important to understand what it might do to our ideas of habitability."Little red dwarfs are fully convective, so nothing spins like a solid would. The Sun spins like a solid, they think, for the core and radiative zones, but convective for the outer zone. The boundary is called the tachocline. I've tended to think this is the place where the seeds for storms begin -- like trailer parks for tornadoes.
But these low mass stars can have a life up to about a trillion years, so a few billion years is long before maturity, whatever that looks like. There should be some older red dwarfs that may exhibit fewer tantrums, or has this been studied already? They are hard to see because they are so dim, so these new giant scopes will offer a great deal more in this area, no doubt. The JWST should help as well given it's longer wavelength advantages.
I have seen descriptions of the early solar system as a pin-ball machine due to all the wild dynamics. The Nice model, IIRC, manages to predict, after wild orbital shifts, all the current planetary orbital locations with the exception of Pluto, so it's not a perfect model.
I think stability came after Jupiter and Saturn found their resonance with one another, but that is going on my memory as well.
These dynamics may have tossed large bodies outward, including Planet 9, if one is ever found.
Given the large number of massive stars found, the observations of more rogue planets seems logical. Space is so big, however, that odds don't favor one coming our way. But, who knows, at least two interstellar objects have paid us a visit, ignoring UFO's, of course.
I'm unsure what you mean by more challenging. Progress for greater capability of discovery is only getting better.
HZ exos are certainly rare. I find only about a dozen with over 5400 confirmed that are about the size of Earth and likely are capable of having liquid water. IMO, the number is likely about 2 or 3x this figure due to the lack of proper equations that define boundaries. The equilibrium temp. method places the Earth outside the HZ, for instances.
But if we extrapolate the, say, 10 HZ exos per 5000 stars, then this number becomes ~200 million for our galaxy assuming only 100 billion stars. But many, if not most, will have unfavorable orbits around the galaxy. Too far out, and poor metal concentrations are possible. Too close may find too turbulent an environment.
However, after running the program just now, using what I call the "Kopp" method (atmospheric approach), there is only one exo that is in the HZ that is close to the size of Earth.
That’s too specific to be plausible, IMO. Is there any dwarf galaxy at that distance? The blast would be non- homogeneous, perhaps more gaussian, so this would affect intensity and distance values.
Agreed. But even if we rule out all M class stars, we still have discovered more G class than M class exos.
Right, if there were in law defining a real phenomena for abiogenesis then we’d all hear of it.
There are no dwarf galaxies at 1.5 Mlyrs, but perhaps the Phoenix dwarf galaxy at 1.44 Mlyrs. hosted this GRB, assuming their distance calculation was, somehow, accurately determined. It's hard to imagine it would be all by its self.
"It’s always been the safer bet that we are quite rare in our galaxy, possibly unique in our intelligence level. But we need to look at a million stars with planets in favorable galactic orbits, not just a few thousand."
That gives us ~ 80% of the known stars w/ only one (so far) exo. But this percent will drop greatly as these were the low-hanging fruit. The harder to observe smaller ones and those with distant orbits, plus non-favorable inclination exos, will grow in number.
Not only was abiogenesis beyond their scientific grasp — it still is— but his greater struggle could have been avoided had he realized the works of the monk Mendel. His first edition ignored speculating on how traits physically transferred to off-spring. He dreamed-up an explanation on subsequent editions, but to his detriment. But no one else offered this important element in the other theories at that time. It took genetics to win the majority of scientists to his theory.
Hi,
This paper may not do a great job of arguing that case. Notice the reference another paper that states the Earth may be experiencing greater ion loss (6E24/sec). It does, however, show the science in determining the strength of winds. They do not that exoplanets may have stronger magnetic fields than Earth, thus allowing protection.
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