Leaving planet Earth for a moment, a SpaceX Falcon 9 rocket arced into the early evening sky last Sunday at 7:27 pm EST. This 3 minute 20 second exposure traces the launch streak over Kennedy Space Center’s Launch Complex 39A. The rocket carried four astronauts en route to the International Space Station on the first flight of a NASA-certified commercial human spacecraft system. Dubbed Resilience, the astronauts’ Crew Dragon spacecraft successfully docked with the orbital outpost one day later, on Monday, November 16. At the conclusion of their six-month stay on the ISS, the Crew-1 astronauts will use their spacecraft return to Earth. Of course about 9 minutes after launch the Falcon 9 rocket’s first stage returned to Earth, landing in the Atlantic Ocean on autonomous spaceport drone ship Just Read The Instructions.
Most star clusters are singularly impressive. Open clusters NGC 869 and NGC 884, however, could be considered doubly impressive. Also known as “h and chi Persei”, this unusual double cluster, shown above, is bright enough to be seen from a dark location without even binoculars. Although their discovery surely predates recorded history, the Greek astronomer Hipparchus notably cataloged the double cluster. The clusters are over 7,000 light years distant toward the constellation of Perseus, but are separated by only hundreds of light years. In addition to being physically close together, the clusters’ ages based on their individual stars are similar – evidence that both clusters were likely a product of the same star-forming region.
What’s creating these long glowing streaks in the sky? No one is sure. Known as Strong Thermal Emission Velocity Enhancements (STEVEs), these luminous light-purple sky ribbons may resemble regular auroras, but recent research reveals significant differences. A STEVE’s great length and unusual colors, when measured precisely, indicate that it may be related to a subauroral ion drift (SAID), a supersonic river of hot atmospheric ions thought previously to be invisible. Some STEVEs are now also thought to be accompanied by green picket fence structures, a series of sky slats that can appear outside of the main auroral oval that does not involve much glowing nitrogen. The featured wide-angle composite image shows a STEVE in a dark sky above Childs Lake, Manitoba, Canada in 2017, crossing in front of the central band of our Milky Way Galaxy.
The month was July, the place was the Greek island of Crete, and the sky was spectacular. Of course there were the usual stars like Polaris, Vega, and Antares — and that common asterism everyone knows: the Big Dipper. But this sky was just getting started. The band of the Milky Way Galaxy stunned as it arched across the night like a bridge made of stars and dust but dotted with red nebula like candy. The planets Saturn and Jupiter were so bright you wanted to stop people on the beach and point them out. The air glowed like a rainbow — but what really grabbed the glory was a comet. Just above the northern horizon, Comet NEOWISE spread its tails like nothing you had ever seen before or might ever see again. Staring in amazement, there was only one thing to do: take a picture. Coverage: NASA’s SpaceX Crew-1 Mission
Why is this galaxy so thin? Many disk galaxies are just as thin as NGC 5866, pictured here, but are not seen edge-on from our vantage point. One galaxy that is situated edge-on is our own Milky Way Galaxy. Classified as a lenticular galaxy, NGC 5866 has numerous and complex dust lanes appearing dark and red, while many of the bright stars in the disk give it a more blue underlying hue. The blue disk of young stars can be seen extending past the dust in the extremely thin galactic plane, while the bulge in the disk center appears tinged more orange from the older and redder stars that likely exist there. Although similar in mass to our Milky Way Galaxy, light takes about 60,000 years to cross NGC 5866, about 30 percent less than light takes to cross our own Galaxy. In general, many disk galaxies are very thin because the gas that formed them collided with itself as it rotated about the gravitational center. Galaxy NGC 5866 lies about 44 million light years distant toward the constellation of the Dragon (Draco). Almost Hyperspace: Random APOD Generator