The legend of the lost country Atlantis and the fate of its inhabitants has been stirring the minds for more than 23 centuries. But much more terrible catastrophes happened in the sky, when whole worlds perished …
Eaters of planets
Like everything else in the world, the stars are also not eternal, and in old age they begin to “freak out”. As the calculations of astrophysicists show, a star of approximately the solar mass leads a completely quiet life of about ten billion years. But then it “grows fat” relatively quickly, increasing its size by tens, and its luminosity by hundreds of times. The swollen giants begin to shine with an ominous crimson, highly volatile light. Their sizes gradually grow, covering the nearest planets.
Back in 1925, using an interferometer, it was possible to directly measure the apparent dimensions of the red giant Mira Ceti. It turned out that the diameter of the star exceeds the solar diameter by 420 times. A clear example of what our Sun will eventually turn into! Expanding, such a monster would “swallow” Mercury, Venus, our Earth and even Mars. It’s scary to imagine what will happen on the other planets, because Mira Ceti continuously changes its apparent brightness by a factor of one and a half with an almost one-year period … But there are also supergiants. So, the "garnet star" mu Cephei has grown fat to the point that in place of the Sun it could swallow even the orbits of Jupiter and Uranus. In this case, life even on Pluto would become impossible - mu Cephei shines like a million modern suns. There is no doubt that such disasters do occur.
The American astrophysicist K. Stark-Marsell even suggested that the periodicity of the maser radio emission from giant stars is explained by shock waves from the motion of large "swallowed" planets such as Jupiter inside them. The fate of planets like the Earth is much sadder - they should simply evaporate … Australian MA Dopita and American J. Libert reported the discovery of signs of the existence of a planet with a mass of Saturn, partially survived inside the red giant, from which now there is a vast envelope-nebula EGB6 and hot core PG 0950 + 139.
Planet Burners
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Theoretical models predict that the process of transformation of an ordinary star into a red giant occurs over many millions of years. But the catastrophe can occur much earlier if the star is several times more massive than the Sun. Such blue and very bright luminaries present deadly surprises even before they turn into red supergiants. Here are some of their "jokes".
The bright blue star Gamma Cassiopeia has not shown noticeable brightness changes over two millennia of observations. However, in 1932, an outbreak began unexpectedly. Over the next five years, the star became brighter almost twice. It's funny that astronomers only noticed this in 1936, although the bright gamut of Cassiopeia is clearly visible all year round. After long fluctuations, the star returned to normal magnitude in 1943. Such a prolonged increase in the brightness of the Sun would raise the temperature on the Earth's surface by at least 43 degrees. And the star simply "lost weight" - a shell of incandescent gas separated from it, which went like a fiery shaft through the surroundings and scattered without a trace. For more than half a century, the insidious star has been "sleeping", but no one knows when she wakes up again.
P Cygnus showed a much more evil disposition. For over three hundred years, this blue star, barely visible to the naked eye, has been at rest, almost without changing its brightness. However, the master of celestial globes V. I. Bleu saw it 5 times brighter in 1600. I saw her the same in 1602-1606. I. Kepler. Then the brilliance began to decline; and by 1621 the star was out of sight. But in 1655-1665, a new five-fold outbreak followed. By 1682, the star weakened and remains barely visible to this day.
But all were surpassed by an asterisk invisible to the naked eye from the constellation Carina, designated by the Greek letter "this". Now it is difficult to imagine that in 1843 the star was 1,500 times brighter, shining in the sky almost like Sirius. The flare lasted for an unprecedented long - at least from 1677 to 1885. During these 208 years, the luminary flared up three times, becoming for decades one of the brightest stars in the sky, then weakened dozens of times. The shell of gas thrown off by the star is now visible as a tiny dumbbell-shaped nebula. Some experts believe that it was already an unsuccessful supernova explosion, but instead of a year or two, the explosion lasted for a couple of centuries …
The explosion of a real supernova is much more terrible - in a matter of days, the brightness of a star increases millions of times, and its dimensions begin to exceed the Earth's orbit! Expansion continues, and an envelope weighing between one-tenth and ten times the mass of the Sun forms a vast nebula many light years across. And such a finale awaits not only massive stars, but also luminaries such as the Sun. A similar catastrophe in our Galaxy happens every hundred years. Absolutely lethal doses of radiation and unimaginable heat sterilize the surroundings of supernovae, leaving only disfigured skeletons of planets revolving around deadly neutron stars and black holes.
Signs of the existence of just such planets - remnants have already been found in the PSR 1257 + 12 pulsar from the periodic changes in the period of its radio flares caused by the orbital motion of this neutron star. There are at least two planets revolving with masses three times greater than that of our Earth. But there is no hope that the atmosphere around the planets melted by a monstrous explosion has been preserved there.
Runaways
In principle, each planet will face the unenviable fate of being devoured or scorched by its decrepit sun. And this has happened many times in the Galaxy. Indeed, judging by the chemical composition and age, our Sun consists of the remnants of the explosions of the most ancient supernovae. The fate of the inhabitants of the vicinity of those extinct suns is unknown. But if they wanted to survive, they had to migrate to other, younger planetary systems.
Were our planets on the path of those migrations? It is very likely, because judging by the close remnants of supernova shells, such catastrophes sometimes happened very close. It is possible that some of the fugitives reached the vicinity of the Earth. At least in some incomprehensible way, the idea of galactic migrations penetrated into the folklore of earthlings … For example, back in the 1850s-1860s an amazing fairy tale was recorded in Podillia: “They say that God created man not on earth, but somewhere - then in another world for a very long time. And as that world came to an end, God, in order to preserve the human race, ordered the angels to take several pairs of people and bring them to the earth so that they would be fruitful … Or maybe this world, as soon as the end comes, then again God will transfer people somewhere … … And this is no exception. The heavenly ancestral home of mankind is spoken of in the myths of many peoples of the world.
There are no less numerous myths in which heavenly beings, having descended, help people to appear (remember at least the Bible). And the question of the deliberate export of genetic material from the stars to Earth has been raised seriously and more than once in the scientific literature. Did the fugitives from dying worlds try to adapt to new conditions using genetic engineering? It is curious that life on Earth appeared suddenly, as if immediately after the formation of tolerable conditions on its surface. Traces of life have already been found in the oldest rocks available for study, almost four billion years old. This is in good agreement with the hypothesis of the American scientists F. H. Crick and L. I. Orgel about the extraterrestrial origin of life on our planet. On the basis of new geological data, this idea was supported by J. Brooks and G. Shaw. They paid attention to the factthat earlier 4 billion years ago the Earth's surface was too hot and dry. There was almost no time for prebiological evolution.
A. V. Arkhipov