Astronomers have discovered the first carbonaceous asteroid in the cold outer regions of the solar system, according to The Astrophysical Journal Letters. The object likely formed in the main asteroid belt between Mars and Jupiter and was later ejected billions of kilometers away into the Kuiper belt.
According to the Great Maneuvering hypothesis, when the solar system was from 1 to 10 million years old, and the terrestrial planets had not yet formed, gas giants wandered around it, now coming closer to the Sun, then moving away from it. Jupiter first migrated from an orbit of 3.5 astronomical units (about 525 million kilometers from the Sun) to an orbit of 1.5 astronomical units, where Mars is now. After him, he pulled Saturn, which was forced to move into an orbit of 2 astronomical units. Naturally, such travels were accompanied by large-scale consequences - it is assumed that the gas giants have cleared the inner part of the solar system from "excess" gas and dust and threw some of the building material for Mercury, Venus, Earth and Mars into its distant corners.
Now, a research group led by Tom Seccull of Queen's University Belfast has found support for this hypothesis and other theories that talk about the wandering of gas giants. Scientists have determined the composition of the asteroid (120216) 2004 EW95 in the Kuiper Belt, which confirmed the fact that the celestial body was once "expelled" from the inner solar system to the outer region.
For the first time, the asteroid 2004 EW95 was noticed by the team of Wesley Fraser, an astronomer at Queen's University in Belfast, during programmed observations on the Hubble. The reflective spectrum of this celestial body - the spectral composition of light waves reflected from the surface of the object - differed from the spectra of similar small bodies of the Kuiper belt, which for the most part were uninformative and did not allow one to judge the chemical composition of objects.
The orbit of the exiled asteroid is shown in red.
Subsequent studies of the asteroid by the Secall group using the X-Shooter and FORS2 receivers at the VLT telescope complex showed that 2004 EW95 is a carbonaceous asteroid. In the near-UV spectrum of the object, there is a dip typical of type C asteroids, which, according to scientists, indicates that 2004 EW95 has a similar origin. Today it is the largest class of asteroids - it includes 75 percent of all known asteroids. In addition, two other features of the spectrum were remarkable, which indicate the presence of iron oxides and phyllosilicates in the asteroid. Previously, these substances were not found in the Kuiper belt. According to scientists, their presence can be considered a convincing argument in favor of the fact that 2004 EW95 was thrown into the Kuiper belt from the inner part of the solar system.
“While there have been reports of other atypical spectra in Kuiper Belt objects before, none have been confirmed with this level of accuracy. The discovery of a carbonaceous asteroid in the Kuiper belt is key confirmation of one of the fundamental predictions of dynamical models for the early solar system,”said Olivier Hainaut, an ESO astronomer who was not part of the research team.
Christina Ulasovich
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