Most Asteroids are Not in the Asteroid Belt
Simulations show that the Oort cloud contains eight billion asteroids (in addition to hundreds of billions of comets). Do these asteroids pose a threat to Earth?
Planet Formation on a Budget
There does not seem to be enough mass in protoplanetary disks to build the planetary systems we’ve detected. The solution: planet formation might start sooner than previously thought.
Rethinking the Planet Formation Deadline
Observational biases may significantly underestimate the lifetime of protoplanetary disks.
Herschel’s View of a Neighboring Planetary System
Herschel provides an updated look at the debris disk in the popular planetary system, Tau Ceti.
Can Icelines Explain Uranus and Neptune?
A new hypothesis posits that the ice giant planets formed between the CO and N2 icelines in the Solar System’s protoplanetary disk.