The comet catwalk discovery in the internal solar system can alter the fundamental understanding of the comet's evolution

A new study by a researcher from the University of Central Florida could fundamentally change our understanding of how comets arrive from the peripheries of the solar system and are directed to the inner solar system moving closer to the Earth.

In a study to appear in the Letters from the Astrophysical Journal This week, scientist Gal Sarid and his co-authors describe the discovery of an orbital "gateway" through which many comets pass before approaching our sun. The catwalk was discovered as part of a simulation of centaurs, small icy bodies traveling in chaotic orbits between Jupiter and Neptune. The study team modeled the evolution of bodies located beyond the orbit of Neptune, across the region of the giant planet and into the interior of the planet. Orbit of Jupiter. These icy bodies are considered almost immaculate remains of matter from the birth of our solar system.

For a long time, the journey of comets from their original formation site to the sun was debated.

"How do the new comets, controlled by the influence of Jupiter, replace those that have been lost? Where is the transition from the outer solar system, as small sleeping bodies, to becoming bodies? internal solar system assets, presenting a generalized coma of gas and dust and tail? " Sarid asks, the main scientist of the study. These questions have remained a mystery until now. "What we discovered, the gateway model as" cradle of comets, "will change the way we think about the history of icy bodies," he says.

The centaurs are believed to have originated from the Kuiper Belt beyond Neptune, and are believed to be the source of the comets of the Jupiter family, which occupy the inner solar system. The chaotic nature of centaur orbits masks 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 coma and elongated tails that we call comets. This display is one of the most impressive phenomena observable in the night sky, but it is also a flash of ephemeral beauty quickly followed by the destruction of the comet or its evolution in sleep, explains Sarid.

The initial purpose of the investigation was to explore the story of a particular centaur – 29P / Schwassmann-Wachmann 1 (SW1), a medium-sized centaur in almost an orbit circular just beyond Jupiter. SW1 has long intrigued astronomers with its high activity and frequent explosive explosions that occur at a distance from the sun where ice should not spray efficiently. Its orbit and activity place SW1 in an intermediate position between other centaurs and comets of the Jupiter family. The research team sought to determine whether the circumstances of SW1 were consistent with the orbital progression of other centaurs, Sarid explains.

"More than one in five centaurs we have tracked up have turned out to be in a similar orbit to SW1 at some point in their lives," said Maria Womack, a scientist at the Institute. Florida space and co-author of the study. "Rather than being a particular peculiarity, SW1 is a centaur caught in the act of dynamic evolution towards a JFC." In addition to the mundane nature of the SW1 orbit, the simulations lead to an even more surprising discovery, says Womack.

"The centaurs that cross this region are the source of more than two-thirds of all JFCs, making them the main gateway through which these comets are produced," said Womack. The Gateway region does not retain resident objects for a long time, as most centaurs become JFCs in a few thousand years. It is a short part of the life of an object in the solar system, which can last for millions or even billions of years.

The presence of the footbridge is a long sought way of identifying centaurs on an imminent trajectory towards the inner solar system. SW1 is currently the largest and most active of the few objects discovered in this gateway region, making it an "ideal candidate to advance our knowledge of the orbital and physical transitions that shape the comet population we see today." "Hey," said Sarid.

Our understanding of comets is intimately linked to knowledge of the early composition of our solar system and the changing conditions for atmospheres and life, the researchers said.