On August 30th, a second interstellar visitor was spotted in the solar system, Hubble providing us today with the clearest view of the object.
In 2017, a first interstellar object – an asteroid 400 meters in diameter called Oumuamua – was spotted in our solar system. A historical first. Since then, we have been visited by another object: comet 21 / Borisov, named after his discoverer. A first color photograph of the object was taken in the night of 9 to 10 September from the Gemini Observatory in Hawaii. More recently, it has been Hubble’s focus on the interstellar object.
A familiar comet
The first data collected thanks to the various telescopes of the planet made it possible to estimate its speed: about 110 000 km / h. We also know that it will be less than 190 million km from Earth in December.
The analyzes of its nucleus – about one kilometer in diameter – also suggest that from a purely physical point of view, this comet is not so different from those born in our system. Which suggests that these objects probably form in the same way elsewhere in the Universe.
Recall that in our system, the two main comet nurseries are the Kuiper Belt, which extends beyond the orbit of Neptune, and the large cloud of Oort located much further, to several thousand astronomical units .
Although another star system may be quite different from ours, the fact that the properties of the comet appear very similar to those of the components of the solar system is remarkable, said Amaya Moro-Martin, of the Space Telescope Science Institute.
Researchers will have the opportunity to study this subject in more detail in the coming weeks. Perhaps they will be able to determine its origin? Regarding Oumuamua, a study published last year suggested that the asteroid came from a two-star system based in the Lyre constellation.