{"id":102869,"date":"2019-09-19T10:47:05","date_gmt":"2019-09-19T14:47:05","guid":{"rendered":"https:\/\/www.ucf.edu\/news\/?p=102869"},"modified":"2020-09-09T10:04:01","modified_gmt":"2020-09-09T14:04:01","slug":"comet-gateway-discovered-to-inner-solar-system-may-alter-fundamental-understanding-of-comet-evolution","status":"publish","type":"post","link":"https:\/\/www.ucf.edu\/news\/comet-gateway-discovered-to-inner-solar-system-may-alter-fundamental-understanding-of-comet-evolution\/","title":{"rendered":"Comet Gateway Discovered to Inner Solar System, May Alter Fundamental Understanding of Comet Evolution"},"content":{"rendered":"

A new study led by a University of Central Florida researcher may fundamentally alter our understanding of how comets arrive from the outskirts of the solar system and are funneled to the inner solar system coming closer to Earth.<\/p>\n

In a study to be published in The Astrophysical Journal Letters <\/em>this week, scientist Gal Sarid and co-authors describe the discovery of an orbital \u201cgateway\u201d through which many comets pass before they approach our sun. The gateway was uncovered as part of a simulation<\/a> of centaurs, small icy bodies traveling on chaotic orbits between Jupiter and Neptune. The study team modeled the evolution of bodies from beyond Neptune\u2019s orbit, through the giant planet\u2019s region, and inside Jupiter\u2019s orbit. These icy bodies are considered nearly pristine remnants of material from the birth of our solar system.<\/p>\n

For a long time, the pathway of comets from their original formation location inward toward the sun has been debated.<\/p>\n

\u201cHow do new comets, controlled by Jupiter\u2019s influence, replace those that are lost? Where is the transition between residing in the outer solar system, as small dormant bodies, and becoming active inner solar system bodies, exhibiting a widespread gas and dust coma and tail?\u201d asks Sarid, the lead scientist for the study. These questions remained a mystery until now. \u201cWhat we discovered, the gateway model as a \u2018cradle of comets,\u2019 will change the way we think about the history of icy bodies,\u201d he says.<\/p>\n

Centaurs are thought to originate in the Kuiper Belt region beyond Neptune and are considered as the source of Jupiter Family Comets, which occupy the inner solar system. The chaotic nature of centaur orbits obscures their exact pathways making it difficult to predict their future as comets. When icy bodies such as centaurs or comets approach the sun, they begin to release gas and dust to produce the fuzzy appearance of the coma and extended tails that we refer to as comets. This display is among the most impressive phenomena observable in the night sky, but it is also a fleeting flicker of beauty that is rapidly followed by either the destruction of the comet or its evolution to a dormant state, Sarid says.<\/p>\n

The original goal of the investigation was to explore the history of a peculiar centaur\u2013 29P\/Schwassmann-Wachmann 1 (SW1), a mid-sized centaur in a nearly circular orbit just beyond Jupiter. SW1 has long puzzled astronomers with its high activity and frequent explosive outbursts that occur at a distance from the sun where ice should not effectively vaporize. Both its orbit and activity put SW1 in an evolutionary middle ground between the other centaurs and the Jupiter Family Comets. The research team wanted to explore whether SW1\u2019s circumstances were consistent with the orbital progression of the other centaurs, Sarid says.<\/p>\n

\u201cMore than one in five centaurs that we tracked were found to enter an orbit similar to that of SW1 at some point in their lifetime,\u201d said Maria Womack, a Florida Space Institute<\/a> scientist and co-author of the study. \u201cRather than being a peculiar outlier, SW1 is a centaur caught in the act of dynamically evolving into a JFC.\u201d In addition to the commonplace nature of SW1\u2019s orbit, the simulations lead to an even more surprising discovery, Womack says.<\/p>\n

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