In the earliest years of planet Earth, while our world was still forming, icy comets were essential carbon sources that could possibly start life, a new study claims.
Astronomers at the University of Minnesota used infrared observations of Comet Catalina when it challenged the inner solar system in 2016 in an effort to better understand the composition of these icy visitors and their role in the evolution of planet Earth.
The team was able to detect significant amounts of carbon in the tail of the comet – a chemical that is essential for life as we know it.
The rocky planets were probably too hot in their earliest days to capture enough carbon for life to begin with, so they had to get the building blocks of life from somewhere.
“Comets rich in carbon could be an important source that could provide 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 passes through the inner solar system with dust and gas evaporating in its tail, shows how these icy visitors may have supplied carbon to warm, early rocky worlds such as the 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 Catalina enters the inner solar system from the Oort cloud, a region on the edge of the solar system where comets are born.
It briefly becomes visible to stargazers on earth before swinging past the sun to disappear forever from the solar system and into interstellar space.
The Stratospheric Observatory for Infrared Astronomy (SOFIA), NASA’s telescope on an aircraft, was among the many observatories that got a glimpse of this comet.
Using one of its unique infrared instruments, SOFIA was able to project a familiar fingerprint into the dusty glow of the comet’s tail – carbon.
This discovery helps planetary scientists explain more about the origin of life on earth, as it ‘becomes comets as Catalina could be an essential source of carbon’ during the early formation of the solar system.
Using new results from SOFIA, a joint project of NASA and the German Aerospace Center, the American team was able to better understand the impact of these comets billions of years ago when planets like Earth and Mars first started form it.
Comet Catalina and others of its kind have such long orbits that they arrive at our threshold relatively unchanged.
It effectively freezes them in time – with much the same thing as was found in the earliest days of the solar system when planets first began to form in the world it is today.
This ‘time capsule’ offers researchers rare opportunities to learn about the early solar system from which they came and how our own planet formed.
NASA was able to observe the icy visitor using infrared cameras, so that astronomers could get a clearer picture of its composition – to find a carbon-rich tail
The infrared observations of SOFIA could capture the composition of the dust and gas as it evaporated from the comet and formed its tail.
The observations showed that comet Catalina is carbon-rich, indicating that it formed in the outer regions of the primary solar system, which contains a carbon reservoir that could be important for sowing life on Earth, Mars and Venus.
Although carbon is an important component of life, it cannot survive over time in a very hot world.
The early Earth and other terrestrial planets of the inner solar system were so hot during its formation that elements such as carbon were lost or depleted.
Infrared observations of the comet helped researchers to see that it was carbon-rich, which enabled them to theorize these comets, helped to sow the warm, rocky early Earth.
The comet Catalina was visible on January 1, 2016 through small telescopes or binoculars when it came closest to Earth on its way to interstellar space
While the cooler gas giants like Jupiter and Neptune can support carbon in the outer solar system, Jupiter’s jumbo size can block the gravity of gravity from interfering with the inner solar system again.
This prompted the U.S. team to investigate how inner rocky planets evolved into the carbon-rich worlds they are today by examining the comet’s data.
Researchers believe that a slight change in Jupiter’s orbit enabled small, early precursors of comets to mix carbon from the outer regions in the inner regions, where it was incorporated into planets such as Earth and Mars.
Comets coming from the outer edges of the solar system, rich in carbon, have been pulled by Jupiter’s massive gravitational force from their wide orbit and pushed closer to the sun to the inner, rocky world.
The carbon-rich composition of comet Catalina helps explain how planets that formed in the hot, carbon-poor regions of the early solar system evolved into planets with the life-supporting element, the authors said.
“All terrestrial worlds are subject to repulsion by comets and other small bodies that carry carbon and other elements,” Woodward added.
“We are getting closer to understanding exactly how this impact on early planets can catalyze life.”
Observations of additional new comets are needed to learn if there are many other carbon-rich comets in the Ear Cloud, which will further support that comets supply carbon and other life-supporting elements to the terrestrial planets.
As the largest observatory in the world in the sky, the mobility of SOFIA can quickly make it possible to observe newly discovered comets as they move through the solar system.
The findings of this study were published in the Planetary Science Journal.