NASA Space Station Blog 21 Jan 2020, 19:29 UTC The Expedition 61 astronauts have one more spacewalk planned this weekend and they will finish the repair of a cosmic ray detector. This will be the ninth spacewalk for the crew, more than in any other increment in the history of the International Space Station.
Astrobiology Magazine 21 Jan 2020, 16:21 UTC New study finds surface waters on early Mars may have been habitable for microbial life
Bad Astronomy 21 Jan 2020, 14:00 UTC We're still not really sure what killed the dinosaurs. I mean that both in general and specifically. Yes, there was an asteroid impact. We know that 66 million years ago, an object roughly 10 kilometers across, either an asteroid or a comet, slammed into what is now the Gulf of Mexico just off the coast of Yucatan. The crater is something like 150 kilometers across and 20 deep, and the impact was so catastrophic that 75% of all species died out, including the non-avian dinosaurs. This is called the Cretaceous-Paleogenic, or K-Pg, extinction.
NASA Space Station Blog 20 Jan 2020, 19:05 UTC At 1:33 p.m. EST, Expedition 61 Flight Engineers Jessica Meir and Christina Koch of NASA concluded their third spacewalk together. During the six hour and 58-minute spacewalk, the two NASA astronauts successfully completed the battery upgrade for one channel on one pair of the station’s solar arrays.
Centauri Dreams 20 Jan 2020, 15:02 UTC “Tidal locking”, “captured rotation” or “spin-orbit locking” etc occurs in most recognised guise when an orbiting astronomical body (be it a moon, planet or even a star) always presents the same face towards the object it is orbiting. In this instance, the orbit of the “satellite” body can be referred to as “synchronous”, whereby the tidally locked body takes as long to rotate around its own axis as to orbit its partner. This occurs due to the primary body’s gravity flexing the orbiting body into an elongated “prolate” shape. This in turn is then exposed to varying gravitational interaction with the central body.