The process of how life started on Earth was unknown to everyone until recently when astronomers solved the mystery of where phosphorus came from. Phosphorus is a key element for life; it is found in everything from humans to the tiniest life forms and is essential to create living forms. The mystery of how phosphorus got to planet Earth remained unresolved for many years.
Astronomers have now traced the journey of phosphorus from star-forming regions to comets using the combined powers of ALMA and the European Space Agency’s probe Rosetta. Their research shows where molecules were containing phosphorus formed, how this element is carried in comets, and how a particular molecule may have played a crucial role in starting a life on Earth.
A new study suggests phosphorus, which is present in DNA and cell membranes of all living organisms, may have been delivered by the icy wanderers billions of years ago. Scientists found evidence of phosphorous monoxide in 67P/Churyumov-Gerasimenko, a comet belonging to the Jupiter family.
Victor Rivilla, of the National Institute for Astrophysics’s Arcetri Astrophysical Observatory in Italy and the lead author on the study, said: “Life appeared on Earth about four billion years ago, but we still do not know the processes that made it possible.”
To find out more, an international team of astronomers used a group of telescopes in Chile called the Atacama Large Millimeter/Submillimeter Array (Alma) to study a region in the constellation of Auriga known as AFGL 5142, where stars are being formed.
Observations showed that when massive stars are formed, they open up cavities in the surrounding interstellar clouds of gas and dust where phosphorus-based compounds, such as phosphorous monoxide, are created.
The astronomers then looked at data from the European Space Agency’s probe Rosetta, which was launched in 2004 to study 67P, and found evidence of phosphorous monoxide. They say the findings allowed them to trace the journey of phosphorus from star-forming regions to comets.
The astronomers believe that when cavity walls in the interstellar clouds collapse to form a star, phosphorus monoxide can get trapped in the icy dust grains that remain around the new star. Those dust grains gradually come together to form pebbles, rocks and ultimately comets, which then become transporters of phosphorus monoxide.
“As comets most probably delivered large amounts of organic compounds to the Earth, the phosphorus monoxide found in comet 67P may strengthen the link between comets and life on Earth.”