Stars Kill Their Planets
Many stars, including sunlike stars, murder their children.
Only special conditions allow for habitability.
This is our best look yet at how young stars stifle planetary formation (Space.com, 7 Jan 2023).
Reporter John Loeffler describes a recently-published report as “the most in-depth study of planet-killing stars ever conducted.” A paper in The Astrophysical Journal shared data from 6,000 “young” stars observed by the Chandra X-Ray Observatory, an orbiting telescope in the series of space telescopes.
Stars like the sun are highly energetic bodies capable of blasting away the atmospheres of planets in their orbits before life could have a chance to take hold, and a new study of a cluster of especially young stars has given us an even better understanding of how this process occurs.
The Chandra X-ray Observatory undertook the most thorough study of magnetically active stars ever conducted to see how the activity of these young stars might affect planet formation in their accretion disks, the mass surrounding young stars that supplies the material they need to develop planetary bodies.
Assuming the current consensus theory for now, planets “accrete” from material in dust disks orbiting their star. The theory has major problems (see 15 Aug 2015), but let’s follow along to see where the observations lead the theorists. The model assumes that young stars are highly energetic, generating intense magnetic fields from internal dynamos. For millions of years, the energy sends powerful X-rays into space toward planets “trying” to accrete or form atmospheres. But there’s a problem: the stars declare war on their children.
The study, which was published in The Astrophysical Journal in August 2022, found that the high X-ray and ultraviolet radiation from these especially young stars are likely to have completely cleared away the gas and dust in their accretion disks in very short order, thereby stunting the growth of planets around them. What’s more, those planets that do form are likely to have their hydrogen-rich atmospheres stripped away in a few million years unless they can produce a strong magnetic field of their own to beat back the barrage, as is the case with our planet.
Summarizing, energetic stars attack in three ways: (1) blasting away the material for planet formation, (2) stripping away the remaining planets’ atmospheres, and (3) wearing out the planets for millions of years longer than they can protect themselves. The abstract of the paper states,
The observed X-ray luminosities can be so high that an inner Earth-mass rocky, unmagnetized planet around a solar-mass PMS star might lose its primary and secondary atmospheres within a few (several) million years. PMS X-ray emission may thus have a significant impact on the evolution of early-planetary atmospheres and the conditions promoting the rise of habitability.
Rocky planets might survive if they get past the war of attrition (removal of dust and gas from the disk), provided they get their magnetic shields up in time. In the case of Earth, though, Dr Henry Richter’s book Spacecraft Earth shows that magnetic fields decline rapidly, and can be gone in just a few thousand years – far less time than the millions of years of a star’s energy budget.
Gamble and Trust Your Lucky Star
Could other star types be more congenial to their planetary offspring? A related article on Space.com from 3 April 2018 announced, “X-Rays Could Spell Doom for Life on Planets Around Red Dwarfs.”
Red dwarfs are the most numerous star types in the universe. Reporter Elizabeth Howell pointed out that red dwarfs not only emit X-rays, but powerful atmosphere-stripping flares, too. The best hope scientists could have for life on an “Earth 2.0” orbiting a red dwarf star is that ocean creatures might survive the flare activity. There would be no land animals or humans on such a world, though. The ozone layer would be stripped away, if not the entire atmosphere.
But as Richter’s book points out, a habitable planet has multiple requirements (at least 15) for complex life. Dr Michael Denton’s book The Miracle of Man narrows down the possibilities even further, especially for large, mobile complex beings like humans.
Update 19 Jan 2023: Right after this article was published, New Scientist announced that “Up to 74% of planets in the ‘habitable zone’ may not be good for life.” They introduced a new term: “belatedly habitable planets.”
While researchers often think of the habitable zone of any given star as being relatively static, it actually changes as the star evolves and its brightness and temperature change. That means that worlds born well outside the habitable zone that started their lives either much too hot or too cold for liquid water on their surfaces could become more temperate later in their stars’ lifetimes.
Noah Tuchow at NASA’s Goddard Space Flight Center in Maryland and Jason Wright at Pennsylvania State University have dubbed these worlds belatedly habitable planets, as opposed to continuously habitable planets that spend their entire existences in the habitable zone. They calculated that, depending on how you define the habitable zone, 29 to 74 per cent of planets could be belatedly habitable.
That has major consequences for the possibility of water on these worlds. Those born closer to their star than the habitable zone may have all of their water boiled away before they enter the habitable zone, and for those born farther away any water is likely to take the form of difficult-to-melt global glaciers.
The term embeds the idea of long ages, but notice that even within the deep-time assumptions, habitability is a fragile thing. Adding time, therefore, does not help materialists get better rolls of the die to account for the origin and development of life. Conditions for habitability not only have to be right; they have to stay right.
Evolution thrives on glittering generalities. When you read glib press releases by evolutionists about the possibility of life on other worlds, or the evolution of habitable planets around other stars, don’t swallow it. Last month, Nature spoke of “potentially habitable worlds” that the James Webb Space Telescope is beginning to observe. A potentially habitable world is like potentially edible elements in the Periodic Table. The important thing is how they are put together.
Computer models are not reality. For instance, Caltech issued a news story on 12 Jan 2023 called, “How do rocky planets really form?” Really? Really! Here come the generalities and assumptions, stated as dogma:
Planetary systems begin their lifecycles as large spinning disks of gas and dust that consolidate over the course of a few million years or so. Most of the gas accretes into the star at the center of the system, while solid material slowly coalesces into asteroids, comets, planets, and moons.
In the article, animation of the new “seismic shift” model shows a dust disk feeding baby planets into orbit around a star like BB’s in a pinball game. Looks easy. One of the storytellers quips, “You basically have a planet factory that only knows how to make planets of one mass, and it just squirts them out one after the other.” Right.
What they didn’t say is that X-rays and flares blast away the disk and fry any remaining fragments trying to hold themselves together. Do any of the “potentially habitable” planets have a magnetic field? A large moon to stabilize the orbit? Water? The right atmospheric gases? An ozone layer? The right obliquity, eccentricity and inclination? Seasons? The right crustal composition? Details, details.
This article causes me to wonder how many years, centuries, millennia remain before earth’s atmosphere gets blasted away due to its rapidly weakening magnetic field.
Good question. Thanks for raising it. Dr Richter discusses that issue in ch. 7 of his book.