The key to understanding how these worlds are built is to consider where they are missing.
On the third day of Christmas the ALMA gave to me, 20 highly resolved protoplanetary disks!
It is difficult to tell if planets embedded in their natal protoplanetary disks are migrating closer to their stars. The authors of today’s paper devise a new observational signature to figure that out.
Planets form from protoplanetary disks. How they can be heavier on average than the disks is questioning our theories of planet formation.
Steep density drop-offs and orbits with high inclinations and eccentricities are just a few of the mysterious features in the outer reaches of our Solar System – can a single stellar fly-by help explain all of them?
Today’s paper describes models of what a nearby supernova would do to a young planetary system, and looks at whether the same may have happened to our own solar system.