SpaceX successfully launched and landed its reusable rocket! This achievement was the first time we’ve ever managed to launch, land, refurbish, and re-use a rocket for a second launch. SpaceX is calling the rocket, a Falcon 9, “flight-proven” as opposed to “secondhand,” “used” or “reused.” The entire launch and landing went off without a hitch, making this the first time in history a firm has launched an orbital rocket that did what the Falcon 9 did last night. Blue Origin has previously demonstrated a sub-orbital rocket takeoff and landing, but Elon Musk made the history books. “It’s been 15 years to get to this point,” Musk said. “It’s taken us a long time. A lot of difficult steps along the way.”
Scientists have put forth a possible explanation for how Enceladus got its “tiger stripes.” In short, something huge could have smashed into the icy moon. “If it was heated by tides, the north and south should look the same,”Angela Stickle of Johns Hopkins University. “So the fact that Enceladus’s south has these crazy regions with plumes and heat flows is enigmatic.” But the heating and the cracks could be explained by a formidable impact: something that hit hard enough to smash in the icy crust like an eggshell. The assailant could then have melted right through the ice, which would have refrozen around it, leaving little trace of its presence beyond the rapidly cooling crush zone and its fissures.
Also, there’s a new hypothesis that proposes a relationship between gravity, dark matter, and black holes. Here’s how it goes. Right now the axion is our best candidate for a WIMP that could crack the dark matter problem. Except it’s hard to find axions. How do you find something scarce? Go to where it’s common. And scientists expect that axions should be more densely concentrated near black holes.
“The basic idea is that we’re trying to use black holes… the densest, most compact objects in the universe, to search for new kinds of particles,” project spokesperson Masha BaryakhtarGizmodo. Especially one particle: the axion. “People have been looking for it for 40 years,” Baryakhtar said.
What makes the hypothesis eye-opening is the metaphor it draws between black holes and the structure of an atom. Think of a black hole as a kind of atomic nucleus, except on a huge scale. The authors suggest that axions might behave en masse like electrons behave in pairs, jumping between energy levels and occupying expected clouds around the nucleus.
But wait: there’s more. The rotation of the black hole could create a phenomenon called superradiance, which could produce 1080 axions, the same number of atoms as we think there are in the entire universe, except all those axions would be orbiting around a single black hole. If we can confirm these hypotheses with LIGO data, it could advance our understanding of dark matter by leaps and bounds, and put us one step further to understanding the why and wherefore of the universe. Whoa.
Source : https://www.extremetech.com/extreme/246901-far-tidings-beyond-rim-week-space