The second interstellar object ever spotted passing through the solar system is a comet that appears quite like those formed in our neighborhood of the cosmos, providing fresh evidence that other planetary systems may be very similar to our own.
Astronomers on Monday provided some of the first details about the comet now hurtling toward the sun, saying it has a solid nucleus with a radius of about six-tenths of a mile (1 km), a cloud-like structure of dust and gas emitted by the nucleus, the telltale tail of a comet and a reddish color.
