NASA’s Juno spacecraft successfully completed its first Jovian orbit and its first and closest flyby to the tops of the gas giant’s cloud banks this week. During its 36 planned orbits, Juno will gather data to help us find out precisely what the core of Jupiter is made of and why it makes the magnetosphere behave like it does. As part of NASA’s big public outreach project, Juno’s visible-spectrum JunoCam will also send us back some glamor portraits of Jupiter and its moons, especially Europa and Io, while it keeps its primary research equipment trained on Jupiter’s poles.
Their Dawn orbiter also made a burn into a higher orbit around Ceres, in order to go a little easier on the satellite’s dwindling reserves of hydrazine. It’s still sending us photos from Ceres, well after its planned EOL, and NASA intends to wring out every bit of science it can.
Following up on an observation of a galaxy cluster some 44,000 light years away, a team of scientists from the Keck Observatory discovered that they’d stumbled on a cosmic oddity: a “failed Milky Way” galaxy they think is made of 99% dark matter. It’s called Dragonfly 44. The few stars visible in the galaxy aren’t big enough to keep each other close with mutual gravity, but still they stay together. We have no trouble seeing through the cluster to what’s behind it, but when we look in that direction, there’s gravitational lensing going on, more than can be explained by the loose, “fluffy” distribution of stars in Dragonfly 44. The conclusion they’ve come to is that there could be a quantity of dark matter dragging the stars in toward the center of the galaxy, and they hope to follow up their observations with other, more conclusive measurements that can help to show us the shape of the hole in our understanding about whatever it is we’re calling dark matter.
Speaking of cold, dark things that are unhelpfully far away and difficult to observe, scientists presented evidence for another planetoid in our solar system, dubbed Planet 9 (from outer space!). Finding out whether it’s really there will require that we zero in further on its present location. This currently involves working backwards from other objects that appear to have been perturbed by Planet 9’s gravitational sway, and then doing the calculations to find its path through time.
Recently scientists located a possibly habitable exoplanet orbiting in the Goldilocks zone around Proxima Centauri, our next-door stellar neighbor. It’s still too far away to directly observe whether or not it has an atmosphere, let alone actually visit to drop a probe on the surface. But it’s right there. Planets are just popping up everywhere these days.
Sadly, the possible extraterrestrial signal SETI was investigating turned out to be a dud. Our first clue was that it didn’t repeat. Also, it was in a weird part of the EM band. Once we really started digging into the signal, the team found that it was the content equivalent of someone’s washer plugged into a poorly grounded outlet. But we keep sending unsolicited nudes into space and trying to find out where the aliens live, so it really shouldn’t be a surprise if they just coast right on by Earth with the headlights off.
Also, from the department of distinctly unwanted news, SpaceX had an earth-shattering kaboom at Cape Canaveral early Thursday morning. During a static test, there was an explosion that appeared to originate from the upper stage of the oxygen tank, according to Elon Musk. The vehicle and payload were both lost. The AMOS-6 satellite that would have enabled Facebook’s internet.org venture was on the vehicle when it exploded, but nobody cares about what makes Zuckerberg cry, and their walled-garden Facebook-branded internet is a terrible idea anyway.
Among SpaceX’s other customers are EchoStar, Iridium and the CRS missions to resupply the International Space Station. EchoStar satellites supply Dish Network and also HughesNet satellite internet customers, while the Iridium constellation is responsible for GPS. Since SpaceX is supposed to be carrying the new Iridium and EchoStar constellations into orbit over the next couple of years, we really, really need them to not have ships blowing up.