When astronomers explore space looking for signs of life, they usually first check the presence and concentration of carbon and oxygen. However, there is still an element that is incredibly important for life, at least on Earth. It may turn out to be the very key that opens up space objects that have optimal conditions for living organisms. We are talking about phosphorus, one of the six chemical elements on which everything in biology is based. Other elements are: oxygen, hydrogen, carbon, sulfur and nitrogen. Without phosphorus, ATP, or adenosine triphosphate, which is incredibly significant in the metabolism and energy of all known living organisms, simply cannot appear. So says astronomer Jane Greaves from Cardiff University, located in British Wales. Phosphorus is quite rare in the universe. This is the rarest element of the six necessary for life around us on Earth. The thermonuclear reaction occurring in the bowels of stars synthesizes it in trace amounts. Moreover, supernovae are the main sources of this substance in the Universe. According to scientists, phosphorus is only 0.0007 percent of the total mass of matter in the universe. According to the latest research by an international team of scientists, some supernovae produce even less phosphorus than usual. So, in general, in the Universe it may turn out to be even less than it seemed so far. Therefore, there are not many places where it is enough for the appearance of life forms that we understand. The earth is lucky, who was not only lucky to be in the temperature zone suitable for life, but managed to get enough phosphorus, which, according to experts, travels through space in meteor rocks after a supernova explosion. The researchers made these conclusions by studying a couple of nebulae: Craboid and Cassiopeia A. As the first results show, the phosphorus in the Crab nebula is much less than in Cassiopeia A. Scientists were surprised by the difference in the content of this substance. Indeed, as computer models demonstrate, both nebulae were formed from supernovae of the same type. Consequently, the volumes of phosphorus in them should be similar. Having understood the reason for the revealed difference, researchers will be able to figure out how the vitally important chemical elements are distributed in the Universe. There is an assumption that this difference is due to the presence of processes occurring in supernova explosions and unknown to science. These processes can affect the synthesis rate of a number of elements. The influence of the age difference between the two nebulae on the indicated discrepancy is also likely. The authors of the study note that they still have to check the conclusions about the differences in the phosphorus content in the found supernova remnants. To help with this in the future, the new James Webb Space Telescope, which has not yet been launched, can conduct infrared observations. According to astrophysicists, it is also optimal for measuring the content of phosphorus in supernova remnants.