COLUMBIA, Md., March 5, 2021 /PRNewswire/ --In 2016, the Comet Catalina hurtled past Earth, before disappearing forevermore out of the solar system. Among the many observatories that captured a view of this comet, which appeared near the Big Dipper, was NASA's t Stratospheric Observatory for Infrared Astronomy (SOFIA). Using one of its unique infrared instruments, SOFIA was able to pick out a familiar fingerprint within the dusty glow of the comet's tail – carbon.
SOFIA--NASA's telescope on an airplane--found that some comets are carbon rich and may be the source of carbon on planets like Earth and Mars. The observations of Comet Catalina as it made its first pass through the solar system and was briefly visible to stargazers, offers new clues about how this essential ingredient for life came to rocky planets in the Sun's inhabitable zone.
According to the paper's lead author, Charles "Chick" Woodward, an astrophysicist and professor at the University of Minnesota's Minnesota Institute of Astrophysics, in Minneapolis, "Carbon is key to learning about the origins of life." He notes "We're still not sure if Earth could have trapped enough carbon on its own during its formation, so carbon-rich comets could have been an important source delivering this essential element that led to life as we know it."
Frozen in time
Originating from the Oort Cloud at the farthest reaches of our solar system, Comet Catalina and others of its type have such long orbits that they arrive on our celestial doorstep relatively unaltered. This makes them effectively frozen in time, offering researchers rare opportunities to learn about the early solar system from which they come.
SOFIA's infrared observations were able to capture the composition of the dust and gas as it evaporated off the comet, forming its tail. The observations showed that Comet Catalina is carbon-rich, suggesting that it formed in the outer regions of the primordial solar system, which held a large reservoir of carbon that could have been important for seeding life.
While carbon is a key ingredient of life, early Earth and other terrestrial planets of the inner solar system were so hot during their formation that elements like carbon were lost or depleted. While the cooler gas giants like Jupiter and Neptune could support carbon in the outer solar system, Jupiter's jumbo size may have gravitationally blocked carbon from mixing back into the inner solar system. So how did the inner rocky planets evolve into the carbon-rich worlds that they are today?
Researchers think that a slight change in Jupiter's orbit allowed small, early precursors of comets to mix carbon from the outer regions into the inner regions, where it was incorporated into planets like Earth and Mars. Comet Catalina's carbon-rich composition 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.
"All terrestrial worlds are subject to impacts by comets and other small bodies, which carry carbon and other elements," said Woodward. "We are getting closer to confirming exactly how these impacts on early planets may have catalyzed life."
Observations of additional new comets are needed to learn if there are many other carbon-rich comets in the Oort Cloud, which would further support that comets delivered carbon and other life-supporting elements to the terrestrial planets. As the world's largest airborne observatory, SOFIA's mobility allows it to quickly observe newly discovered comets as they make a pass through the solar system.
SOFIA is a joint project of NASA and the German Aerospace Center. NASA's Ames Research Center in California's Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA's Armstrong Flight Research Center Building 703, in Palmdale, California.
Founded in 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA), is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs, under Federal funding. USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise. More information about USRA is available at www.usra.edu.