Rosetta spacecraft finds ‘vital ingredients’ of Earth life in comet dust
Among the elements discovered were glycine and phosphorous, which are important components of DNA, RNA and cell-membranes. The European Space Agency’s Rosetta spacecraft spotted them in samples from a gas and dust cloud of the 67P/Churyumov-Gerasimenko comet, scientists said on Friday. It was the first time phosphorous was discovered around a comet.
“This result demonstrates that comets could have played a crucial role in the emergence of life on Earth,” scientists wrote in the paper published in the Journal of Science Advances.
Glycine was also detected back in 2006 in samples returned from another comet Wild 2. However they were said to have suffered contamination issues.
The fact that glycine was detected twice is no coincidence and means that it is a common element in the universe, scientists claimed.
“Having found glycine in more than one comet shows that neither Wild 2 nor 67P are exceptions,” said Kathrin Altwegg of the University of Bern in Switzerland, leading author of the paper.
“Amino acids are everywhere, and life could possibly also start in many places in the universe,” Altwegg added.
The “exact story” behind life’s formation on Earth is unknown and scientists have voiced different theories regarding the issue. One of them is that comets and meteorites landed into Earth’s oceans bringing organic components necessary to “generate” life.
“Meteorites and now comets prove that Earth has been seeded with many critical biomolecules over its entire history,” said University of Washington astronomer Donald Brownlee, a principal investigator of NASA’s Stardust comet sample return mission.
“You need more than amino acids to form a living cell,” Altwegg said. “It’s the multitude of molecules which make up the ingredients for life.”
“Demonstrating that comets are reservoirs of primitive material in the Solar System and vessels that could have transported these vital ingredients to Earth, is one of the key goals of the Rosetta mission, and we are delighted with this result,” said ESA’s Rosetta project scientist Matt Taylor.
Scientists said they planned to look for other organic materials around the same comet.
67P is a comet rotating around the sun between the orbits of the planets Jupiter and Earth. Last August it reached its closest encounter to the sun and is currently on its way towards Jupiter.