Those of us who love astrobiology get really worked up about the lack of Earth-sized exoplanets found at Earth-like distances from their stars. All we want, we who hope for lots of extraterrestrial life, is a bunch of Earth-like planets doing Earth-like things so we can feel better about the odds for lots of Earth-like life in the universe.
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.
Observational biases may significantly underestimate the lifetime of protoplanetary disks.
Of all the kinds of planets we’re finding around other stars—hot Jupiters and mini-Neptunes and those dubiously called “Earth-like”—super-Earths orbiting close to their stars are among the most abundant. While planets so close to their stars are poor candidates for habitability, they are important to understanding the possibility of other habitable planets in these seemingly common systems.
A new model explains Mercury’s major density with magnetism.
A new model simulates the composition of growing planetesimals in an evolving protoplanetary disk. The model predicts that carbon-rich terrestrial planets can form more easily than previously thought.
A close encounter with another star can disrupt the protoplanetary disk of a young star, leaving a smaller disk behind. Can we learn anything about the encounter from the size of the remaining disk? Read on to find out!
Close encounters with a passing star can excite a planet into an eccentric or inclined orbit. But a circumstellar disk can damp a planet’s eccentricity and inclination. Who wins? Find out when the authors of this paper model a stellar flyby with two circumstellar disks!
The mass of a substellar companion can help determine whether it’s a planet or a brown dwarf. But how can you measure the mass of a companion that you can’t detect directly? Look at the disk!
There’s a lot going on in the HD 142527 protoplanetary disk — accretion, gap opening, and a horseshoe-shaped dust ring. The authors of this paper used ALMA to take a closer look at the gas and dust in this busy disk.