The Las Cumbres Observatory has captured a new image of the giant comet C/2014 UN271 (Bernardinelli-Bernstein) that shows its activity despite its considerable distance given that it’s far beyond Saturn’s orbit. The information collected also by looking into archive images such as the ones that allowed to identify it in an image from 2014 is useful to better understand its characteristics. In particular, initial estimates suggested that its diameter was at least 100 kilometers, three times the largest known comet, but these are estimates based on the absence of a coma. C/2014 UN271 will remain far from the Sun, arriving close to Saturn’s orbit at the beginning of 2031, so it can only be admired with telescopes but it could still be very interesting because it probably comes from the Oort cloud.

Two articles published in the journal “Nature” report different studies on the materials present in the atmospheres of comets, which appear to contain iron and nickel even in the ones far from the Sun. Jean Manfroid, Damien Hutsemekers, and Emmanuel Jehin used data collected by the UVES spectrograph of ESO’s VLT in Chile to analyze the atmospheres of various comets detecting the presence of both iron and nickel. Piotr Guzik and Michał Drahus used the X-shooter spectrograph, also of the VLT, to examine in particular the interstellar comet 2I/Borisov detecting the presence of nickel. They were surprising results because the sublimation of heavy metals was thought possible only near the Sun.

An article published in “The Astronomical Journal” reports a description of the characteristics of comet P/2019 LD2. A team of researchers used observations conducted with various space and ground-based telescopes to examine P/2019 LD2 while it’s passing near the planet Jupiter in a trajectory that brought it close to the Trojan asteroids to the point that it was initially mistaken for one of them.