Astronomers have spotted what they believe is the second object of interstellar origin ever observed in the Solar System. Comet C/2019 Q4. Image credit: G. Borisov. C/2019 Q4 is a relatively large active comet between 1.2 and 10 miles (2-16 km) in diameter. Also designated 2I/Borisov, the object was discovered by Gennady Borisov, an amateur astronomer from Crimea, Ukraine, on August 30, 2019. About a week later, NASA and ESA astronomers obtained images...
