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New York: A colossal and frontal collision between Jupiter and a planet still in formation at the beginning of the solar system, about 4.5 billion years ago, has left the Jupiter nucleus less dense and more extensive than expected, according to researchers .
Even if this impact occurred 4.5 billion years ago, "it may still take many, many billions of years for heavy materials to fall back into a dense core under the suggested circumstances. by the document, "said researchers who analyzed NASA's readings published by NASA spacecraft.
Astronomers from Rice University and Chinese University Sun Yat-sen say that their direct impact scenario may explain Juno's previously astonishing gravitational readings.
"It's amazing, that suggests something happened that stirred the core, and it's there that the giant impact comes into play," said L & # 39; Rice astronomer and co-author of the study, Andrea Isella, in an article published in the journal Nature.
According to Isella, the main theories about planet formation suggest that Jupiter began as a dense, rocky or icy planet that then collected its thick atmosphere from the primordial disk of gas and dust that gave birth to our sun.
Isella said that he was skeptical when the lead author of the study, Shang-Fei Liu, suggested for the first time that the data could be explained by a giant impact that stirred the core of Jupiter, mixing the dense contents of its nucleus with less dense layers above.
The research team performed thousands of computer simulations and discovered that a rapidly growing Jupiter could disrupt the orbits of nearby "planetary embryos", protoplanets at the onset of planet formation.
The crash scenario became even more appealing after Liu had used 3D computer models that showed the impact of a collision on the Jupiter core.
"Because it is dense and there is a lot of energy, the impactor would be like a bullet that goes through the atmosphere and hits the core hard," he said. declared Isella.
"Before the impact, you have a very dense core, surrounded by atmosphere.The frontal impact expands things and dilutes the core."
"The only scenario that has resulted in a core density profile similar to what Juno is measuring today is a frontal impact with a planetary embryo about 10 times larger than Earth," Liu said.
The Juno mission was designed to help scientists better understand the origin and the evolution of Jupiter.
Launched in 2011, the satellite features instruments to map Jupiter's gravitational and magnetic fields and to probe the deep inner structure of the planet.
(IANS)
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