The Milky Way, the galaxy we live in, is part of a cluster of more than 50 galaxies that make up the 'Local Group', a collection that includes the famous Andromeda galaxy and many other far smaller objects. Now a Russian-American team have added to the canon, finding a tiny and isolated dwarf galaxy almost 7 million light years away.
One type of aurora is known as a 'theta aurora' because seen from above it looks like the Greek letter theta - an oval with a line crossing through the centre. While the cause of the auroral oval emissions is reasonably well understood, the origin of the theta aurora was unclear until now.
To paraphrase Mark Twain, the report of the Kepler spacecraft's death was greatly exaggerated. Despite a malfunction that ended its primary mission in May 2013, Kepler is still alive and working. The evidence comes from the discovery of a new super-Earth using data collected during Kepler's 'second life'.
Astronomers have discovered that black holes don't have to be nearly so powerful to shut down star formation. By observing the dust and gas at the center of NGC 1266, a nearby lenticular galaxy with a relatively modest central black hole, the astronomers have detected a 'perfect storm' of turbulence that is squelching star formation in a region that would otherwise be an ideal star factory.
This spectacular image of the star cluster Messier 47 was taken using the Wide Field Imager camera, installed on the MPG/ESO 2.2-meter telescope at ESO's La Silla Observatory in Chile. This young open cluster is dominated by a sprinkling of brilliant blue stars but also contains a few contrasting red giant stars.
NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill.
An interstellar mystery of why stars form has been solved thanks to the most realistic supercomputer simulations of galaxies yet made. Theoretical astrophysicists found that stellar activity - like supernova explosions or even just starlight - plays a big part in the formation of other stars and the growth of galaxies.
First measurements by the Rosetta mission's ROSINA instrument show that the deuterium-to-hydrogen (D/H) ratio of the comet 67P/Churyumov-Gerasimenko is highly enriched in deuterium. These results contradict the theory that the water present in the Earth's atmosphere and oceans has a cometary origin.
Scientists have picked up an atypical photon emission in X-rays coming from space, and say it could be evidence for the existence of a particle of dark matter. If confirmed, it could open up new perspectives in cosmology.