In the early years of planet Earth, as our world was still forming, frozen comets were essential sources of carbon that could have initial life, according to a new study.
University of Minnesota astronomers used infrared observations of Comet Catalina as they ventured into the inner solar system in 2016, in an attempt to better understand the composition of these frozen visitors and their role in the development of planet Earth.
The team was able to detect significant amounts of carbon – a chemical essential for life as we know it – in the comet’s tail.
The rocky planets were probably too hot in the early days to catch enough carbon for life to begin, so they had to get the basics of life somewhere.
“Carbon-rich comets could have been an important source that provided this essential element that led to life as we know it,” says study author Charles Woodward.
This illustration of a comet in the Oort cloud passing through the inner solar system, with dust and gas evaporating in its tail, shows how these frozen visitors could have delivered carbon to hot, early rocky worlds such as Earth.
Carbon-rich Comet Catalina was first discovered in 2013 on its last and first journey through the inner solar system
In early 2016, Comet Catalina entered the inner solar system from the Oort cloud, a region right on the edge of the solar system where comets are born.
It briefly became visible to Earth’s stars before hovering over the sun to disappear forever from the solar system and into interstellar space.
Among the many observatories that captured a view of this comet, which appeared near Carul Mare, was the Stratospheric Observatory for Infrared Astronomy (SOFIA), NASA’s telescope on an airplane.
Using one of its unique infrared instruments, SOFIA was able to choose a familiar imprint in the dusty glow of the comet’s tail – carbon.
This discovery helps planetary scientists explain more about the origins of life on Earth, because “they become apparent comets like Catalina could have been an essential source of carbon” during the early formation of the solar system, the team explained.
Using new results from SOFIA, which is a joint project of NASA and the German Aerospace Center, the US team was able to better understand the impact these comets had billions of years ago when planets such as Earth began to form. and Mars.
Comet Catalina and others of this kind have orbits so long that they reach our celestial threshold relatively easily.
This actually causes them to freeze over time – with the same matter as found in the early days of the solar system, when the planets first began to form in the world they are in today.
This “time capsule” offers researchers rare opportunities to learn about the early solar system they came from and how our own planet would have formed.
NASA was able to observe the frozen visitor using infrared cameras, allowing astronomers to get a clearer picture of its composition – finding a carbon-rich tail
SOFIA’s infrared observations were able to capture the composition of dust and gas as it evaporates from the comet, forming its tail.
Observations have shown that Comet Catalina is rich in carbon, suggesting that it formed in the outer regions of the primordial solar system, which had a carbon reservoir that could have been important for the sowing of life on Earth, Mars and Venus.
Although carbon is a key ingredient in life, it cannot survive over time in a very hot world.
Early Earth and other terrestrial planets in the inner solar system were so hot during their formation that elements such as carbon were lost or depleted.
The comet’s infrared observations helped researchers see that it is rich in carbon, allowing them to theorize these comets, helping to seed the hot and rocky early Earth.
Comet Catalina was visible through small telescopes or binoculars on January 1, 2016, as it made the closest approach to Earth on its way into interstellar space.
While colder gas giants, such as Jupiter and Neptune, could support carbon in the outer solar system, Jupiter’s jumbo dimension could gravitationally block carbon from mixing back into the inner solar system.
This led the US team to investigate how the inner rocky planets evolved in the carbon-rich worlds they are in today, examining data from the comet.
Researchers believe that a slight change in Jupiter’s orbit allowed the comets’ small precursors to mix carbon from the outer regions into the inner regions, where it was incorporated into planets such as Earth and Mars.
Comets came from the outer edges of the solar system, rich in carbon, were pulled from their wide orbit by the massive gravitational force of Jupiter and pushed to the inner worlds, rocky, closer to the sun.
The high-carbon composition of Comet Catalina helps explain how the planets that formed in the hot, carbon-poor regions of the early solar system evolved into planets with the life-supporting element, the study authors said.
“All terrestrial worlds are impacted by comets and other small bodies that carry carbon and other elements,” Woodward added.
“We are getting closer to understanding exactly how these impacts on the early planets could have catalyzed life.”
Observations of additional new comets are needed to find out if there are many other carbon-rich comets in the Oort cloud, which would further argue that the comets have delivered carbon and other life-supporting elements to Earth.
Being the largest aerial observer in the world, SOFIA’s mobility allows it to quickly observe newly discovered comets as they pass through a solar system.
The findings of this study were published in the Planetary Science Journal.