The list of factors needed for life to originate on Earth remains uncertain, although water was essential. Earth’s water was likely delivered by planetesimals scattered inward by Jupiter. Yet, ironically, Earth would probably be much wetter with no Jupiter. … More Water delivery and the origin of life on Earth
TL;DR: The giant planets underwent a dynamical instability that shook up the entire Solar System and likely ejected an extra ice giant. The instability happened early, perhaps triggered by the dispersal of the gaseous planet-forming disk. … More The giant planet instability (the “Nice model”)
TL;DR: Most giant planets form in a bottom-up way, by first growing large cores and then piling gas on top. They migrate throughout their formation. Jupiter may have protected Earth from migrating ice giants. … More Growth and migration of the giant planets
TL;DR: Earth- to Neptune-mass planets migrate through the disk — usually inward, and fast. Giant planets carve gaps in the disk (“anti-donuts”) and migrate slowly, usually inward. Things can get crazy when lots of planets migrate together. … More Orbital migration
Where are those Trojans? Just where are they hiding?
Are they at the store, or maybe hang-gliding?
We think they exist — just what have we missed?
Well, every good story should end with a twist… … More The mystery of the missing planets