Our place in the Universe, for so long one of the core mysteries of the human Earthly existence, just got a little clearer and a bit more terrifying, according to Brent Tully at the University of Hawaii Institute for Astronomy. Tully leads an ongoing effort to map the distribution of galaxies around the Milky Way that recently discovered an immense structure in the vast cosmic web beyond Laniakea, a supercluster of galaxies and endless voids, including the Milky Way and a newly identified structure, the South Pole Wall.
A ‘Holy Grail’ of astronomy is to provide a clear map of our galaxy –a perspective of Earth’s relationship to the physical universe where our solar system drifts between two spiral arms at its outer edges of the Milky Way, some 27,000 light-years from its opaque central disk. Beyond that, like the maps of ancient sea-faring mariners, is a terra ingognito, the “zone of avoidance” where no space craft has yet to ever travel beyond the opaque central disk.
Nyx, a vast new stellar stream discovered in the vicinity of the Sun, named after the Greek goddess of the night, may provide the first indication that a dwarf galaxy had merged with the Milky Way disk. These stellar streams are thought to be globular clusters or dwarf galaxies that have been stretched out along its orbit by tidal forces before being completely disrupted.
There’s been increasing speculation that many of the Milky Way’s more than 4,100 known exoplanets might resemble the ocean worlds of Jupiter’s storied moon Europa and Saturn’s Enceladus. “So if we’re thinking about these places as being possibly habitable, maybe bigger versions of them in other planetary systems are habitable too,” says NASA’s Lynnae Quick about planets with oceans that may be orbiting many of our galaxy’s one trillion stars.
New research based on huge simulations involving hundreds of processors on the Australian National Computing Infrastructure using parameters run through a unique geodynamics code simulating the development of the interior of planets, showed that many early planets would have tended to develop a magnetic field and plate tectonics than planets formed later in the Milky Way, which is favorable to the development of life.
“Plumes of water erupt from Europa and Enceladus, so we can tell that these bodies have subsurface oceans beneath their ice shells, and they have energy that drives the plumes, which are two requirements for life as we know it,” says Lynnae Quick, a NASA planetary scientist who specializes in volcanism and ocean worlds, about speculation that many of the more than 4,000 known exoplanets might resemble some of the watery moons around Jupiter and Saturn. “So if we’re thinking about these places as being possibly habitable, maybe bigger versions of them in other planetary systems are habitable too.”
