manuel flores, the gang member the united states sent back to el salvador, says he planning to return, too. >> sreenivasan: go inside the notorious 18th street gang, one of the most dangerous in el salvador. read our producer's notebook from that country at newshour.pbs.org. >> this is pbs newshour weekend, saturday. >> sreenivasan: tucked away in the constellation taurus in distant space, planets are being born. how do we know? because scientists are observing it happen more clearly than ever before. using the alma radio telescope in chile, astronomers were able to capture this image showing a star surrounded by a large disc made of gas and dust. it may look like an artist's illustration, but, in fact, at the center of this image is the real h.l. tauri star. and the dark rings-- that's believed to be the dust and gas coming together to form planets, meteors and asteroids. h.l. tauri is 450 light years from earth, and even though it's almost one million years old, astronomers consider it quite young. for decades, astronomers have known of the existence of the star but have never been