Related papers: Spaceflight from Super-Earths is difficult
Astronomers are debating whether the plentiful "sub-Neptune" exoplanets -- worlds a bit larger than Earth but smaller than Neptune -- are predominantly rocky planets, water-rich "ocean worlds," or gas-enshrouded mini-Neptunes. This question…
Recent x-ray and radio data from radio sources in galaxy clusters are used to show that the pdV work required to inflate the radio lobes exceeds all other energy estimates deduced from the radio emission. If the required jet energy density…
Super-Earths are highly irradiated, small planets with bulk densities approximately consistent with Earth. We construct combined interior-atmosphere models of super-Earths that trace the partitioning of water throughout a planet, including…
Whereas the Solar System has Mars and Europa as the best candidates for finding fossil/extant life as we know it - based on complex carbon compounds and liquid water - the 263 (non-pulsar) planetary systems around other stars as known at 15…
The surface gravity on Mars is smaller than the surface gravity on Earth, resulting in longer falling times. This effect can be simulated on Earth by taking advantage of air resistance and buoyancy, which cause low density objects to fall…
The search for extraterrestrial intelligence on exoplanets is a rich field of conceptual exploration. Author introduces two definitions that could help to narrow down the possibilities that an extraterrestrial civilization may or may not…
With over 1800 planets discovered outside of the Solar System in the past two decades, the field of exoplanetology has broadened our perspective on planetary systems. Research priorities are now moving from planet detection to planet…
We know that giant planets played a crucial role in the making of our Solar System. The discovery of giant planets orbiting other stars is a formidable opportunity to learn more about these objects, what is their composition, how various…
Secular perturbations from binary stars and distant massive planets can drive cold planets onto nearly parabolic orbits with pericenter passages extremely close to their host stars. Meanwhile, short-period super-Earths are frequently…
Migration of bodies under the gravitational influence of almost formed planets was studied, and probabilities of their collisions with the Earth and other terrestrial planets were calculated. Based on the probabilities, several conclusions…
Two longstanding problems in planet formation include (1) understanding how planets survive migration, and (2) articulating the process by which protoplanetary disks disperse---and in particular how they accrete onto their central stars. We…
Differentiation in terrestrial planets is expected to include the formation of a metallic iron core. We predict the existence of terrestrial planets that have differentiated but have no metallic core--planets that are effectively a giant…
Super-Earths belong to a class of planet not found in the Solar System, but which appear common in the Galaxy. Given that some super-Earths are rocky, while others retain substantial atmospheres, their study can provide clues as to the…
One primary reason for the formulation of the term Earth-like planet and the search for such planets in the galaxy is because life has arisen in such a world. Thus, this search seems justifiable as it is known here what one is looking for.…
The formation of satellites is thought to be a natural by-product of planet formation in our Solar System, and thus, moons of extrasolar planets (exomoons) may be abundant in extrasolar planetary systems, as well. Exomoons have yet to be…
As of 2025, over 6000 planets are known to orbit stars other than our Sun. We can measure their sizes and orbital periods, infer their masses and temperatures, and constrain their compositions. Based on these data, about 1% of extrasolar…
Low-mass planets have an extraordinarily diverse range of bulk compositions, from primarily rocky worlds to those with deep gaseous atmospheres. As techniques for measuring the masses of exoplanets are advancing the field towards the…
Exoplanets around different types of stars provide a window into the diverse environments in which planets form. This chapter describes the observed relations between exoplanet populations and stellar properties and how they connect to…
The ejection of planets by the instability of planetary systems is a potential source of free-floating planets. We numerically simulate multi-planet systems to study the evolution process, the properties of surviving systems, and the…
Extrasolar planetary systems range from hot Jupiters out to icy comet belts more distant than Pluto. We explain this diversity in a model where the mass of solids in the primordial circumstellar disk dictates the outcome. The star retains…