A headline-grabbing paper calculated the prevalence of Earth-sized planets with long orbital periods around Sun-like stars. But are these planets anything like Earth?
This article uses theoretical modeling to estimate the influence of ice and snow on the habitability of extrasolar planets. This work differentiates itself from past efforts by including the influence of the atmosphere, and by considering planets orbiting M-dwarfs in addition to Sun-like stars.
The search for exoplanets in their habitable zones continues. But exomoons could be habitable, too! This paper models hypothetical exomoons in four real systems to determine the habitability of moons around planets that don’t necessarily stay in the habitable zone.
Detailed atmospheric models reveal that planets can be habitable much closer to their host star than previously thought, provided they have desert-like climates. This expanded definition of the habitable zone increases the number of planets that could support life by a factor of 2-3.
The census of planets for smaller stars—M dwarfs—is now basically complete. In this paper, Courtney Dressing and Dave Charbonneau use this M dwarf advantage to determine the occurrence rate of small planets around M dwarfs.
In our search for life on other planets, we begin by determining which exoplanets orbit in the habitable zone of their star. But where exactly is the habitable zone for a given star? The authors of this paper update a previous planetary climate model to predict where you should looking for your next extrasolar vacation home.
The holy grail for exoplanet science would be to find an inhabited planet. Not just habitable, but actually inhabited. But where are we most likely to find those planets? Only around Sun-like stars, or could life thrive around other types of stars? Could evolved stars like white dwarfs or neutron stars harbor life? Could brown dwarfs, the so-called failed stars, have inhabited planets?
Of Kepler’s 2,321 planet candidates, many are in the “habitable zone.”
Why do we care so much about finding an Earth-like planet? Is our goal to eventually colonize this planet, to make it an outpost from which to explore the rest of our galaxy? Is it pure curiosity about what else is out there? Or is it fueled by human kind’s endless romance with the stars? Exoplanet discoveries don’t usually make me wax philosophical but you’ll have to forgive a momentary lapse before I move on to the science: the discovery of the first Earth-sized exoplanets, Kepler-20e and f.
The First Kepler Science Conference is occurring this week at NASA Ames. Check out this summary of the conference to learn about the exciting results from the Kepler mission.