The team used the Osiris instrument at the 10.4m Gran Telescopio Canarias in La Palma, Spain, to obtain visible spectra - measurements of sunlight reflected by Borisov. By studying these spectra, scientists can draw conclusions about its chemical composition, including how it might differ from comets that were "born" around the Sun. "The spectrum is the red side of the comet's total spectrum, so the only thing we can see in the spectrum is the slope," said Miquel Serra Ricart, from the Instituto de Astrofísica de Canarias (IAC) in Tenerife. In coming days, the team will obtain measurements of the...