According to a new study, during the early years of planet Earth, when our world was still forming, icy comets were essential sources of carbon that could start life.
University of Minnesota astronomers used infrared observations of Comet Catherine when they ventured into the inner solar system in 2016 to try to better understand the composition of these icy visitors and their role in the development of planet Earth.
The team was able to detect significant amounts of carbon, an essential chemical for life as we know it, in the comet’s tail.
The rocky planets were probably too hot in their early days to trap enough carbon for life to begin, so they had to get the basic components 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 from the Oort cloud as it traverses the inner solar system with dust and gas evaporating in its tail shows how these icy visitors may have delivered carbon to early, hot rocky worlds like Earth.
The carbon-rich comet Catalina was first discovered in 2013 on its last and first journey through the inner solar system.
In early 2016, Comet Catherine entered the inner solar system from the Oort cloud, a region near the solar system where comets are born.
It became briefly visible to Earth observers before the sun passed to shoot forever more from the solar system and into interstellar space.
Among the many observatories that captured a vision of this comet, which appeared near the Great Bear, was the Stratospheric Observatory of Infrared Astronomy (SOFIA), NASA’s telescope on an airplane.
Using one of its unique infrared instruments, SOFIA was able to detect a known fingerprint within the dusty brightness of the comet’s tail: carbon.
This discovery is helping planetary scientists explain more about the origins of life on Earth, as it is “making it clear how comets Catherine could have been an essential source of carbon” during the early formation of the solar system, he explained the team.
Using new results from SOFIA, which is a joint project of NASA and the German Aerospace Center, the American team was able to better understand the impact these comets could have had billions of years ago when they began. to form planets like Earth and Mars.
Comet Catherine and others of its kind have such long orbits that they arrive relatively unaltered at our celestial gate.
This causes them to freeze effectively over time, with the same matter that was found in the early days of the solar system when the planets began to form in today’s world.
This “time capsule” offers researchers few opportunities to learn about the first solar system they come from and how our own planet may have formed.
NASA was able to observe the icy visitor using infrared cameras, which allowed astronomers to get a clearer picture of its composition: finding a carbon-rich tail.
SOFIA infrared observations were able to capture the composition of dust and gas as it evaporated from the comet, forming its tail.
Observations showed that comet Catherine is rich in carbon, suggesting that it formed in the outer regions of the primordial solar system, which contained a carbon deposit that could have been important in sowing life on Earth, Mars, and Venus.
Although carbon is a key ingredient in life, it cannot survive over time in a very hot world.
Primitive 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.
Infrared observations of the comet helped researchers see that it was rich in carbon, which allowed them to theorize these comets and helped seed the hot, rocky Earth early.
Comet Catherine was visible through small telescopes or binoculars on January 1, 2016 as it moved closer to Earth on its way to interstellar space.
While colder gas giants like Jupiter and Neptune could support carbon in the outer solar system, Jupiter’s enormous size may have gravitationally blocked carbon from mixing back into the inner solar system.
This prompted the American team to investigate how the inner rocky planets evolved into the carbon-rich worlds they are today by examining data coming from the comet.
Researchers think a slight change in Jupiter’s orbit allowed small comet precursors to mix carbon from the outer regions to the inner regions, where it was incorporated into planets such as Earth and Mars.
The comets came from the outer edges of the solar system, rich in carbon, were ripped from their wide orbit by the massive gravitational force of Jupiter and pushed into the inner and rocky worlds closest to the sun.
The carbon-rich composition of Comet Catherine helps explain how the planets that formed in the warm, carbon-poor regions of the first solar system evolved into planets with the life-supporting element, according to the authors of the study. ‘study.
“All terrestrial worlds are subject to impacts from comets and other small bodies, which carry carbon and other elements,” Woodward added.
“We are getting closer to understanding exactly how these impacts on the first planets may have catalyzed life.”
Observations of additional new comets are needed to know if there are many other carbon-rich comets in the Oort cloud, which would support the comets delivering carbon and other life-supporting elements to terrestrial planets.
As the world’s largest airborne observatory, SOFIA’s mobility allows it to quickly observe newly discovered comets as they pass through the solar system.
The findings of this study have been published in the journal Planetary Science Journal.