Sometimes lightning occurs out near space. One such lightning type is red sprite lightning, which has only been photographed and studied on Earth over the past 25 years. The origins of all types of lightning remain topics for research, and scientists are still trying to figure out why red sprite lightning occurs at all. Research has shown that following a powerful positive cloud-to-ground lightning strike, red sprites may start as 100-meter balls of ionized air that shoot down from about 80-km high at 10 percent the speed of light. They are quickly followed by a group of upward streaking ionized balls. Featured here is an extraordinarily high-resolution image of a group of red sprites. This image is a single frame lasting only 1/25th of a second from a video taken above Castelnaud Castle in Dordogne, France, about three weeks ago. The sprites quickly vanished -- no sprites were visible even on the very next video frame. via NASA https://ift.tt/sQvWMF0
Messier 15 is an immense swarm of over 100,000 stars. A 13 billion year old relic of the early formative years of our galaxy it's one of about 170 globular star clusters that still roam the halo of the Milky Way. Centered in this sharp reprocessed Hubble image, M15 lies some 35,000 light-years away toward the constellation Pegasus. Its diameter is about 200 light-years, but more than half its stars are packed into the central 10 light-years or so, making one of the densest concentrations of stars known. Hubble-based measurements of the increasing velocities of M15's central stars are evidence that a massive black hole resides at the center of the dense cluster. M15 is also known to harbour a planetary nebula. Called Pease 1 (aka PN Ps 1), it can be seen in this image as a small blue blob below and just right of center. via NASA https://ift.tt/aQoCO61
by Jason Rainbow TAMPA, Fla. — Northrop Grumman’s MEV-2 satellite servicer is performing close proximity operations with Intelsat’s in-orbit 10-02 spacecraft ahead of a docking attempt, SpaceNews has learned. Both spacecraft remain healthy after being in close quarters to calibrate and test systems before MEV-2 backed off, according to a Northrop Grumman official. The company intends to release an update once it completes the docking. It is understood the satellite servicer’s predecessor MEV-1 made several close proximity operations maneuvers and approaches before successfully attaching to Intelsat-901 last year , enabling the 19-year-old satellite to resume services from April 2. MEV-2 has a similar design to MEV-1, but the two missions have distinct differences. While Intelsat-901 was no longer functioning as it languished in a graveyard orbit, Intelsat-10-02 has been active in geosynchronous orbit since 2004 and is carrying communications traffic. The two companies a...
