we know of 5,000 so called "exoplanets" — those worlds that are orbiting stars beyond our sun — but all of them have been located within the milky way galaxy. this saturn—sized planet discovered by nasa's chandra x—ray telescope is in the messier 51 galaxy. it is 28 million light—years away from the milky way. if i told you one light year is 5.8 trillion miles. that's a big bus ride. dr rosanne di stefano is an astrophysicist and one of the resarchers behind the study. this is quite extraordinary. what we know about this planet?— know about this planet? welcome eviction summarised _ know about this planet? welcome eviction summarised the - know about this planet? welcome eviction summarised the main - know about this planet? welcome - eviction summarised the main feature which is that it is most likely size is comparable to the size of saturn. the other thing we know about it is the system that orbits. it's an extraordinary system among all of