Powerful new telescopes and new techniques are letting scientists probe planets in the earliest stages of development
⇐ cover image: Credit: NASA/JPL-Caltech [top]. NASA/JPL-Caltech/T. Pyle (SSC) [bottom]
The Basics of Making a Planet
Planets develop out of protoplanetary disks surrounding young stars. Gas and dust particles within these disks glom together into larger bodies, building up over millions of years into full-size planets. The biggest objects capture huge, gassy atmospheres, becoming gas giants. However, this «core accretion» model does not work well at creating gas giants in tight or distant orbits from stars. Nor is the accretion process itself well understood. Newer theories propose that gas giants can migrate toward or away from their stars as a solar system dynamically evolves. In the process, numerous fledging worlds are gravitationally displaced into unusual orbits or expelled into interstellar space. Overall, many questions remain about how, where and when planets arise.
THE SECRETS OF PLANET FORMATION are becoming harder to keep. In November, using a new observing method, scientists snapped the very first pictures of an extrasolar planet still gathering up mass from its dusty, planetary nursery. Called LkCa 15 b, this immature gas giant has opened a window into the poorly understood process of how planets form.
In January, The Kavli Foundation spoke with three planetary formation experts. The discussion covered promising new ways of studying how giant planets form and whether they can explain the rise of our entire Solar System.__more⇒
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