By combining observations of the ALMA radio telescope and data from the Rosetta interplanetary probe, astronomers traced the phosphorus path from star formation to comets. For the first time, it was possible to trace where phosphorus-containing molecules are formed and how this element is on comets. The results of the study are reported by the European Southern Observatory press release.
Phosphorus is essential for living organisms, it is present in DNA molecules and cell membranes. But how phosphorus came to Earth during its formation remains unclear. “Life appeared on Earth about 4 billion years ago, but we still don’t know what processes led to it,” says the lead author of the current study, Victor Rivilla.
Using the ALMA radio telescope, astronomers obtained a detailed picture of the star-forming area of AFGL 5142 and identified areas of phosphorus-containing molecules such as phosphorus oxide. Gas flows from young massive stars form in interstellar clouds of cavities and voids. Phosphorous molecules are formed on the walls of these cavities in the process of the combined impact of shock waves and radiation of a newborn star. Astronomers have also shown that phosphorus oxide is the most common phosphorus-containing molecule on the walls of such a cavity. If the walls of the cavity collapse and form a star, in particular, not very massive, such as our Sun, the surrounding molecules of phosphorus oxide can fall into the grains of ice dust, concentrated around the newborn star. And even before the star is fully formed, these dust grains stick together and form a larger pebble, stones and finally comets, which become carriers of phosphorus oxide.
Therefore, the researchers turned to the data of the orbiting spectrometer ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) on the Rosetta probe, which for two years studied the chemical composition of comet 67P Churyumov-Gerasimenko. Astronomers have already found traces of phosphorus in this data, but did not know exactly which molecules it is included in. Kathrin Altwegg, research director at ROSINA and author of the new study, said she realized what a molecule might be after an astronomer exploring areas approached her at the conference. ALMA: “She said that phosphorus is a very plausible candidate for the role. I revisited our data and realized that I had found what I was looking for!”
Thus, for the first time discovered on the comet, the monoxide phosphorus allows astronomers to trace the path of the molecule from the area of star formation to its appearance near the Earth as part of the comet. “Phosphorus is an essential element of life in the form we know of,” adds Altwegg. “Since it is very likely that comets have brought a large number of organic compounds to Earth, the detection of phosphorus oxide in comet 67P reinforces the assumption of a link between comets and life on Earth.”
The study is published in the journal Monthly Notices of the Royal Astronomical