Can life spread from Earth to the moons of Jupiter and Saturn on rock ejected from meteoroid collisions? The authors of this paper start on answering this question by asking if ejected material from Earth can even reach the gas giants’ moons. The answer is yes, so it’s possible that microbial Earthlings have already traveled a lot farther than human ones.
Comet ISON will be flying by on its way from the Oort Cloud to the Sun and back for the next couple months. Will the meteoroids it leaves behind produce any meteor showers here on Earth? The authors of this paper use orbital mechanics to find out.
Transit observations can yield a lot of information about exoplanets. If a transiting exoplanet encounters stellar wind, the bow shock created can show up in the transit light curves. In this paper, the authors investigate how the stellar wind of a star can shape the light curves we observe.
Galaxy Zoo is a citizen science project that uses volunteers to classify galaxies from the Sloan Digitial Sky Survey as spiral or elliptical. Now the Galaxy Zoo 2 catalogue has gone public, with even more detailed classifications of galaxies, including bars, bulges, spiral arms, and round and squashed ellipticals.
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.
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.
There’s a strange sickle-shaped object in the Carina Nebula. The authors of this paper used observations at several different wavelengths to investigate the nature of this intriguing nebula, leading to some interesting discoveries and even more questions.
Based on galactic rotation curves, we think that spiral galaxies are embedded in massive dark matter halos. Is the same true for elliptical galaxies? Magain and Chantry use gravitational lensing to measure the mass-to-light ratios in 15 elliptical galaxies, and the results might surprise you!
Previous authors have claimed that the black hole at the center of NGC 1365 is spinning extremely rapidly. But these claims are based on certain assumptions about the dominance of relativistic effects on the spectrum of NGC 1365. Risaliti et al., dig deeper into the spectral data of this X-ray source and use simulations to determine whether the signatures we see are caused by a rapidly-spinning black hole, or just cloudy (galactic) weather.