For the first time ever, astronomers detected heavy metals in the frigid atmospheres of comets.
(CN) — With the help of powerful telescopes, two teams of Europe-based researchers found clouds of heavy metal vapors surrounding dozens of comets soaring through our solar system, according to a pair of studies published Wednesday.
Comets — the giant clusters of frozen gas, rock and dust shooting across the night sky — may not support life but they have played a vital role in distributing water and other organic elements across the universe.
They also provide a kind of floating, living archive of the early developmental phases of our solar system, according to researcher Emmanuel Jehin of the University of Liège in Belgium.
“Comets formed around 4.6 billion years ago, in the very young solar system, and haven’t changed since that time,” Jehin said in a statement released with the study. “In that sense, they’re like fossils for astronomers.”
The presence of heavy metals within the rocky cores and exteriors of comets has long been a fact known to scientists. The cloudy trails comets leave in their wake are produced when dust and heavy metals on the space rock are heated by the sun.
The heavy metals typically don’t become gaseous or sublimate at low temperatures when comets are far from the sun, which is why astronomers were stunned at their findings.
A team of Belgium-based astronomers turned the powerful European Southern Observatory’s Very Large Telescope (ESO’s VLT) to the heavens to scan the dusty, bright, comet trails to search for signs of heavy metals.
The VLT’s Ultraviolet and Visual Echelle Spectrograph allows astronomers to uncover the unique chemical signatures of heavy metals tied to cosmic objects.
After analyzing ESO VLT images using spectroscopy, the researchers detected nickel and iron vapors in comets nearly 300 million miles from the sun — or three times the distance between Earth and the sun, according to the studies published in the journal Nature.
Lead researcher Jean Manfroid of the University of Liège said in a statement the findings were a surprise.
“It was a big surprise to detect iron and nickel atoms in the atmosphere of all the comets we have observed in the last two decades, about 20 of them, and even in ones far from the sun in the cold space environment,” Manfroid said.
The quantities of both nickel and iron in comets’ atmospheres were relatively equal, a sharp contrast from other space objects such as meteorites, which generally contain about ten times more iron than nickel.
“Usually there is 10 times more iron than nickel, and in those comet atmospheres we found about the same quantity for both elements,” researcher Damien Hutsemékers said in the statement. “We came to the conclusion they might come from a special kind of material on the surface of the comet nucleus, sublimating at a rather low temperature and releasing iron and nickel in about the same proportions.”
The team is still working to determine what implications the findings have on our understanding of development in the early phases of our universe, according to the study titled “iron and nickel atoms in cometary atmospheres even far from the sun.”
A study by Poland-based scientists titled “Gaseous atomic nickel in the coma of interstellar comet 2I/Borisov” — which also relied on ESO’s VLT data — found that heavy metal vapors are also present in 2I/Borisov, a comet observed 186 million miles from the sun.
“The simultaneous identification of this species in the cold comae of both 2I/Borisov and local comets shows that they have even more in common than was previously thought, and strengthens the affinity between the unknown birthplace of 2I/Borisov and our own solar system,” researchers wrote in the study.
Study coauthor Piotr Guzik of the Jagiellonian University in Poland said in a statement the findings were also a shock considering heavy metal vapors have generally only been found in comets with hotter atmospheres.
“At first we had a hard time believing that atomic nickel could really be present in 2I/Borisov that far from the sun,” Guzik said. “It took numerous tests and checks before we could finally convince ourselves.”
Researchers did not immediately respond to a request for further comment on the study.