Astronomers have found a galaxy
that is made almost entirely of a mysterious, invisible substance
called dark matter. The dark matter galaxy is called Dragonfly 44. It’s roughly the same size as the Milky Way, so you could argue it’s kind of like our evil twin galaxy made of dark matter. Or, as the researchers put it, “Dragonfly 44 can be viewed as a failed Milky Way.” The discovery could help us finally answer 2
big questions about dark matter.
After sunset a partially cloudy sky can promote a beautiful show of colours, seen here over Cerro Paranal, in northern Chile. Stormy looking clouds are unlikely to release any rain in this exceptionally arid area, but they add a striking feature to the sky over two Auxiliary Telescopes (AT) of the ESO’s Very Large Telescope (VLT) array.
Under dark skies the setting of the Milky Way can be a dramatic sight. Stretching nearly parallel to the horizon, this rich, edge-on vista of our galaxy above the dusty Namibian desert stretches from bright, southern Centaurus (left) to Cepheus in the north (right). From early August, the digitally stitched, panoramic night skyscape captures the Milky Way’s congeries of stars and rivers of cosmic dust, along with colors of nebulae not readily seen with the eye. Mars, Saturn, and Antares, visible even in more luminous night skies, form the the bright celestial triangle just touching the trees below the galaxy’s central bulge. Of course, our own galaxy is not the only galaxy in the scene. Two other major members of our local group, the Andromeda Galaxy and the Triangulum Galaxy, lie near the right edge of the frame, beyond the arc of the setting Milky Way.
What’s happening to that meteor? Some time ago, a bright fireball was photographed from the Alps mountain range in Switzerland as it blazed across the sky. The fireball, likely from the Taurids meteor shower, was notable not only for how bright it was, but for the rare orange light it created that lingered for several minutes. Initially, the orange glow made it seem like the meteor trail was on fire. However, the orange glow, known as a persistent train, originated neither from fire nor sunlight-reflecting smoke. Rather, the persistent train’s glow emanated from atoms in the Earth’s atmosphere in the path of the meteor – atoms that had an electron knocked away and emit light during reacquisition. Persistent trains often drift, so that the long 3-minute exposure actually captured the initial wind-blown displacement of these bright former ions. The featured image was acquired when trying to image the famous Orion Nebula, visible on the upper left. The bright blue star Rigel, part of the constellation of Orion, is visible to the right.
Object Names: Object from the Taurid Meteor Shower