Astronomers looking for signs of life in outer space usually look for the presence and concentration of chemical elements such as oxygen and carbon. However, another element that is very important, at least for life on Earth, could be the key to discovering systems inside the Milky Way that have suitable conditions for the existence of living organisms.
“Phosphorus is one of six chemical elements that biology depends on. Other elements are carbon, hydrogen, nitrogen, oxygen, and sulfur. Without phosphorus, the appearance of adenosine triphosphate (ATP), which is of great importance in the metabolism of energy and substances in organisms, is impossible,”Popular Mechanics quotes the words of Jane Greaves, an astronomer at Cardiff University in Wales (UK).
Phosphorus is a relatively rare element in the universe and the rarest of the six essential for the life that surrounds us. In trace amounts, it is synthesized in the course of a thermonuclear reaction in the interiors of stars, but the main source of phosphorus in the Universe is supernovae. It is believed that phosphorus is only 0.0007 percent of the mass of matter in the Universe.
However, a new study by an international team of scientists suggests that some supernovae produce less phosphorus than others, and in general, its content in the Universe may be even less than expected, which means that there are fewer places where it is enough for life to begin. …
The researchers came to such conclusions after studying two nebulae - Cassiopeia A and the Crab nebula. Early results indicate that the Crab Nebula contains significantly less phosphorus than Cassiopeia A.
Cassiopeia A.
The difference in phosphorus content surprised scientists, as computer models show that the two nebulae were formed from the same type of supernova, and therefore should contain a similar volume of this element. Understanding the reason for this difference can help us understand how vital chemical elements are distributed throughout the universe.
According to one of the assumptions, this difference may mean that processes not yet known to science during supernova explosions lead to more or less intense synthesis of some elements. It is also possible that the discrepancy is due to the difference in age between the two nebulae. Light from a supernova explosion that gave birth to the Crab Nebula reached Earth about a thousand years ago. Testimonies about him have been preserved in the Chinese chronicles compiled at least one thousand years ago. In turn, the light from the explosion of the star that gave rise to the Cassiopeia Nebula reached Earth just 300 years ago. And we have no information about the earlier period of observation.
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“Perhaps phosphorus and its compounds, which appeared in the Crab Nebula, could eventually pass from the gaseous phase to the solid. At least this could explain the difference in the gas spectra of the two nebulae,”scientists say.
However, a simpler explanation is possible: when the William Herschel telescope in Hawaii was aimed at the Crab Nebula, the sky was cloudy, and this could distort the measurement results.
The conclusions about different phosphorus contents in supernova remnants have yet to be verified, the authors of the work note. This can be helped by the new space telescope "James Webb", the launch of which, by the way, was recently postponed again. The device will be designed to carry out observations in the infrared range and, according to scientists, is perfect for measuring the level of phosphorus in supernova remnants. Nevertheless, if it turns out that the above conclusions are correct, then this will mean that life in the Universe has even less chances than we thought.
Nikolay Khizhnyak