The first interstellar migrant in the Solar System

Astronomers have discovered the first permanent migrant in our solar system. The asteroid, currently orbiting Jupiter, is the first known object to be captured from another star system and stay with us permanently.

Last year, the eyes of all astronomersów were stuck in an interstellar asteroid ‘Oumuamua – 400-meter rock from another planetary system, która has passed at breakneck speed through our solar system. Wóof them knew at the time that another interstellar intruder had taken up residence in our neighborhood.

When 1I/2017 U1 was spotted, for that is how `Oumuamua is listed in the collection, researchers realized that our solar system must have been visited by other such objects beforehand. And they were right. The interstellar intruder just discovered is likely to have been here for a billionóin years. The `Oumuamua was just a tourist, while 2015 BZ509 is a long-term resident.

Astronomers first spotted object 2015 BZ509 in 2014. It orbits Jupiter. They will immediately attract the attention of researchers. All the planets in our solar system, as well as the vast majority of other objectów, subróThey are living wokół the Sun in the same direction. However, 2015 BZ509 is different – it is moving in the opposite direction on the so-called “orbit”. retrograde orbit. On top of that, the object’s orbit is highly elongated.

To verify the origin of the newcomer, researchers conducted a series of more than a million computer simulations of the asteroid’s orbit, with któeach of which had slightly different parameters. Jupiter’s orbit is a busy part of the solar system, where the risk of changing course is high, so eccentric orbits thatóre are stable long-term, they are unlikely. However, researchers have discovered a number of such orbits. Someóre of them backwards in time suggest that 2015 BZ509 may be with us coóexist since the beginning of our solar system. This would mean that it arrived here about 4.5 billion years ago, when the Earth was just being born.

– Howób asteroid arrived here and is moving in the opposite direction to the rest of the planets, sharing an orbit with Jupiter, was a mystery until now, explained Dr. Fathi Namouni, head of theówny author of the study, które appeared on the pages of the „Monthly Notices of the Royal Astronomical Society: Letters”. – If 2015 BZ509 came from our system, it should have the same primary direction as all other planets and asteroids, inherited from the cloud of gas and dust from which itórych were created – added.

Researchers believe that 2015 BZ509 móhead for millions of years to drift in space until it was captured by the gravity of our star. – Migration of asteroids from other systemsów is possible. The Sun was formed in a densely packed cluster of stars, where every star had itsój own system of planets and asteroids. Proximity to stars, aided by the gravitational forces of the planets, enables such systems to intercept asteroids – said Helena Morais, coóauthor of the study.

The discovery of the first permanent migrant in the Solar System has important implications for the study of planet formation, Solar System evolution and perhaps the origin of life itself. Understanding when and how object 2015 BZ509 settled in our neighborhood can provide cluesówek about the cluster where the Sun was formed.

Sourceóbackground: Science, Royal Astronomical Society, fot. C. Veillet / Large Binocular Telescope Observatory