400 meter big chunks hurtling at high speed through our planetary system

Interstellar Guest: An object that could come from interstellar space is currently raging through our solar system . The chunk discovered a few days ago dipped into our system almost perpendicular to the planetary plane and is now racing towards the constellation of Pegasus. Its extremely high speed and the unusual trajectory speak for an interstellar origin of this object, as the astronomers report. It would be the first proof of such an interstellar visitor.

At present, a 400-meter chunk races through the solar system, probably from interstellar space. © NASA

Almost all objects that fly around in our solar system are of domestic origin: asteroids are concentrated in the asteroid belt between Mars and Jupiter, comets usually come from the Kuiper belt in the outer area of ​​our solar system. The solar magnetic field and the particle streams emanating from the sun act as a barrier to interstellar space, preventing dust and smaller objects from reaching us.

Dipped from above

But now, for the first time, astronomers have discovered an object that does not seem to come from our solar system. The approximately 400-meter big asteroid or comet was discovered by the Pan-STARRS telescope in Hawaii on 19th of October 2017 as NASA reported. Using several more telescopes, the researchers then traced the trajectory of the A / 2017 U1 named object.

They discovered something astonishing:

The movement of this object fits neither a normal asteroid nor the trajectory of a comet, says Rob Weryck from the University of Hawaii.

The chunks plunged from the direction of the constellation Lyra almost perpendicular to the planetary plane into the solar system and flew between sun and Mercury on September 2.

Distracted by solar gravity, A / 2017 U1 then made a curve below the orbital plane, which led it past Earth on October 14th, 60 times the distance to the Moon. Meanwhile, the chunk has passed the orbital plane again and rages out of the solar system at 44 kilometers per second in direction of constellation Pegasus, as the astronomers report.

Trajectory of A / 2017 U1 in September and October 2017. © NASA / JPL-Caltech

...and out again quickly

This is the most extreme orbit I've ever seen, says Davide Farnocchia from NASA's Center for Near-Earth Object Studies (CNEOS). The object is extremely fast and on a trajectory that will almost certainly lead it directly out of our solar system.

That this asteroid or comet will return again, the researcher considers extremely unlikely.

The astronomers conclude from their previous data that A / 2017 U1 can not be an asteroid or comet from the solar system. Instead, the chunk must come from interstellar space. If further observations confirm this, this would be the first interstellar object observed in our solar system.

First detection of interstellar visitor

We have been waiting for this day for decades, says Paul Chodas from CNEOS. It has long been suspected that such objects exist - asteroids or comets that fly between the stars and now and then rush through our solar system - but this is the first direct evidence, so far everything indicates that this is indeed an interstellar object .

Currently, telescopes all over the world and also in orbit are following the further trajectory of A / 2017 U1. The astronomers hope that they will learn more about the origin and composition of this unusual chunks through the data collected. If its interstellar origin confirms, then the naming of this object would have to be adapted to it, as the researchers explain. The International Astronomical Union (IAU) would then have to establish a nomenclature for such interstellar guests.

Source: NASA/JPL-Caltech