The Hubble Space Telescope has captured the best picture yet of a high-speed comet visiting our solar system from another star. NASA and the European Space Agency released the latest photos Thursday. The interstellar comet was discovered last month by a telescope in Chile. Astronomers originally estimated the size of its icy core at several miles across, but Hubble's observations have narrowed it down to no more than 3.5 miles. It's only the third known object from another solar system to pass our way. It poses no threat to Earth.
