Astronomers have spotted a planet in the act of formation for the first time ever, by searching for the special red light the process emits.
Despite all that has been discovered about the basics of planet formation, there is still much that scientists don’t know about how planets like those in our Solar System were first made.
The alien world LkCa 15b, which orbits a star 450 light years away, is on its way to becoming a planet similar to our system’s Jupiter and is the first world formation ever seen in action.
Artist’s illustration shows how planets could form in a transition disk around a star similar to LkCa 15. By isolating the hydrogen-alpha light from the vicinity of that star, astronomers at Stanford and the University of Arizona were able to identify a planet in the early stages of formation. (NASA/JPL-Caltech)
http://www.forbes.com/sites/bridaine...net_formation/
like I don't understand 