Sarlaccs might live in a galaxy far, far away, but our star-studded home has plenty of its own strange wonders.
OXON HILL, MARYLAND, UNITED STATES, EARTH, SOLAR SYSTEM, MILKY WAYWhen we look up, every star we see is in the Milky Way, the spiral galaxy we call home. The Milky Way holds every alien planet humans have ever spotted, and the billions more that likely exist in the galaxy.
On a dark night, the dense plane of the Milky Way winds like a ribbon across the sky. On a really dark night, in areas free from light pollution, that ribbon becomes so intensely spangled with stars that it’s possible to see the dark, dusty clouds of dust and gas deep in space that blot out their light. Those clouds are so prominent that Australia’s Aboriginal people saw them create the shape of an emu.
Our galactic home is one of trillions of galaxies in the universe. Astronomers have been ardently studying them for almost a century, ever since Edwin Hubble discovered that neighboring Andromeda was not just another nearby dusty nebula, but a galaxy in its own right. And yet, humans are still trying to unravel the secrets of our galactic home and how it fits in the tapestry of the universe.
“I would love to see a movie in time of the assembly of the Milky Way,” saysJay Lockman of the Green Bank Observatory, who presented new observations about our galaxy this week at the 231st meeting of the American Astronomical Society in Maryland.
Here are some of the fun, weird facts and questions we have about the 13.6-billion-year-old space oddity we inhabit.
A HUNDRED MILLION STARS IN 3 MINUTESIn January 2015, NASA released the largest image ever of the Andromeda galaxy, taken by the Hubble telescope. By zooming into the incredible shot, filmmaker Dave Achtemichuk creates an unforgettable interactive experience.
The Milky Way Is (Mostly) Flat
Our galaxy is, on average, a hundred thousand light-years across but only a thousand light-years thick. Within this flattened (though somewhat warped) disc, the sun and its planets are embedded in a curving arm of gas and dust, putting the solar system about 26,000 light-years away from the galaxy’s turbulent core. A bulge of dust and stars swaddles the galactic center, looking like a dollop of whipped cream plopped on both sides of a pancake.
Earth Is 18 Galactic Years Old
The solar system is zooming through interstellar space at around 500,000 miles an hour. Even at that rate, it takes about 250 million years to travel once around the Milky Way. The last time our 4.5-billion-year-old planet was in this same spot, continents fit together differently, dinosaurs were just emerging, mammals had yet to evolve, and the most profound mass extinction in the planet’s history—an event called the Great Dying—was in progress.
There’s a Monster Black Hole in the Galaxy’s Middle
Called Sagittarius A*, the supermassive black hole weighs in at more than four million times the mass of the sun. We’ve never seen this object directly—it’s hidden behind thick clouds of dust and gas. But astronomers have been able to follow the orbits of stars and gas clouds near the galactic center, which allowed them to infer the mass of the cosmic heavyweight hiding behind the curtain. It’s thought that supermassive black holes are parked in the cores of most galaxies, and some are feeding on nearby matter so greedily they shoot out jets of powerful radiation visible from millions of light-years away.
You can take a spin through the Milky Way’s chaotic center courtesy of a new animation released at the AAS meeting.