We can be more alone in the Universe than we think. According to Cardiff University astronomers, Jane Greaves and Phil Cigan, the phosphorus of the chemical element is abundant on Earth, but it can be very rare outside of our Solar System. Because phosphorus is essential for life, its rarity can mean that life can be equally rare.
One of the pillars of the search for extraterrestrial life is that there is nothing exceptional about Earth or our Solar System. The assumption is that planets like our Earth, stars like our Sun and galaxies like our Milky Way are common. Therefore, the conditions that gave rise to life here must also be equally common, so by extension life must also be.
The problem is that the origin and evolution of life are very complex processes that depend to a large extent on the presence of various elements and conditions. If one of these elements turns out to be extremely rare, then the spontaneous emergence of life becomes extremely difficult. An example of this is phosphorus, which is relatively common on Earth, but may be the result of an uncommon event.
"Phosphorus is one of the six chemical elements on which terrestrial organisms depend, and it is crucial for the compound adenosine triphosphate (ATP), which cells use to store and transfer energy," says Greaves. "Astronomers have just begun to pay attention to the cosmic origins of phosphorus and found quite a few surprises." In particular, [phosphorus] is created in supernovas – explosions of massive stars – but the amounts seen so far do not match our computer. what would be the implications for life on other planets if the unpredictable amounts of [phosphorus] are spat out in space and then used in the construction of new planets. "
To learn more about how phosphorus is produced, in November 2017, Cardiff scientists turned to the William Herschel telescope in Great Britain on La Palma, in the Canary Islands. They used the giant infrared instrument to observe the phosphorus and iron spectra in the Crab Nebula. About 6,500 light-years away in the constellation of Taurus, the Crab Nebula was formed by a supernova explosion that was recorded by Chinese astronomers in 1054 CE. The idea was that by comparing the spectra of the nebula with that of another supernova remnant, astronomers could gain a better understanding of the origin and distribution of phosphorus.
"This is just the second phosphor study that has been done," says Cigan. "The first one examined the supernova remnant Cassiopeia A (Cas A), and so we can compare two different star explosions and see if they expel different proportions of phosphorus and iron, the first element is compatible with life, while the second is an important element. part of the core of our planet.
"These are our preliminary results, which we have extracted only in recent weeks. But at least for the parts of the Crab Nebula that we observed so far, there seems to be much less phosphorus than in Cas A. The two explosions seem to differ from each other, perhaps because Cas A results from the explosion of a rare supermassive star. We just asked for more telescope time to go back and check, in case we have missed some phosphorus-rich regions in the Crab Nebula. "
According to the team, the comparison indicates that phosphorus may be unevenly distributed In the galaxy, as the element is created by particular types of supernovas and taken to form planets in meteorites or other objects, this could mean that the life that arose on Earth could have depended on the Solar System forming the proximity of the luck of a Phosphorus escape However, other planets may not have been so fortunate.To find out if this is the case, the Cardiff team plans to observe other supernova remnants to see if a similar shortage of phosphorus can be seen.
route to bring phosphorus to the newborn planets seems quite precarious, "says Greaves. We already believe that only a few phosphorus-containing minerals that came to Earth – probably in meteorites – were sufficiently reactive to be involved in the elaboration of proto-biomolecules.
"If phosphorus comes from supernovas and then travels through space in meteorite rocks, I wonder if a young planet might lack reactive phosphorus because of the place it was born in. That is, did it start near the wrong type of supernova? In that case, life could have difficulties to start with phosphorus-poor chemistry, in another world similar to ours. "
The research will be presented at the European Week of Astronomy and Space Science in Liverpool.
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