News about asteroid 2015 BZ509, the wrong-way driver in our solar system and an asteroid immigrant

Asteroid 2015 BZ509 has an orbit around Jupiter (photo: NASA) but moves in the opposite direction.

A study shows that our sun captured this celestial interloper / In the Kuiper Belt was discovered an uncommon celestial body

A new study has discovered the first known permanent immigrant to our Solar System. The asteroid – with the catchy name (514107) 2015 BZ509 – is currently nestling in Jupiter’s orbit. It is the first known asteroid to have been captured from another star system and is in so far quasi a long-term resident in our spheres. The work is published in the Monthly Notices of the Royal Astronomical Society: Letters.

All of the planets in our Solar System, and the vast majority of other objects as well travel around the Sun in the same direction. However 2015 BZ509 is different – it moves in the opposite direction in what is known as a ,retrograde’ orbit.

„How the asteroid came to move in this way while sharing Jupiter’s orbit has until now been a mystery,” explains Dr. Fathi Namouni, lead author of the study. „If 2015 BZ509 were a native of our system, it should have had the same original direction as all of the other planets and asteroids, inherited from the cloud of gas and dust that formed them.”

However, the team ran simulations to trace the location of 2015 BZ509 right back to the birth of our Solar System, 4.5 billion years ago when the era of planet formation ended. These show that it has always moved in this way, and so could not have been there originally and must have been captured from another system.

„Asteroid immigration from other star systems occurs because the Sun initially formed in a tightly-packed star cluster, where every star had its own system of planets and asteroids,” comments Dr. Helena Morais, the other member of the team.

Monthly Notices of the Royal Astronomical Society: Letters

2015 BZ509 in a simulation

This artist's impression shows the exiled asteroid 2004 EW95. Source: ESO/M. Kornmesser

Using ESO telescopes, an international team of astronomers has investigated a relic of the primordial Solar System. The scientists found that the unusual Kuiper Belt Object 2004 EW95 is a carbon-rich asteroid, the first of its kind to be confirmed in the cold outer reaches of the Solar System. This curious object likely formed in the asteroid belt between Mars and Jupiter and has been flung billions of kilometers from its origin to its current home in the Kuiper Belt.

European Southern Observatory (ESO)

(21.06.2018, USA: 06.21.2018)