Astronomers Watch The Birth Of An Alien Planet

The newborn planet PDS 70b (bright spot right of center). (Credit: ESO/A. Müller et al) For decades, astronomers have thought that planets form out of the rotating disks of debris that encircle most newly formed stars. Within these so-called protoplanetary disks — which can be up to 1,000 astronomical units wide (1 AU is the average Earth-Sun distance of 93 million miles) — particles of gas and dust clump together over time, slowly but surely forming larger bodies that may eventually reach planetary status. However, despite years of searching, astronomers have so-far failed to directly image a planet forming within one of these hot and chaotic disks. That is, until now. In a new study published online Monday in the journal Astronomy & Astrophysics, a team of astronomers presented the first convincing observation of a planet-sized object orbiting within the circumstellar disk of its host star — in this case, ...