Earth 16,000 MPH Faster, 2000 Light-Years Closer to Supermassive Black Hole in the Center of the Milky Way
Position and velocity map of the Milky Way Galaxy. Arrows show position and velocity data for the 224 objects used to model the Milky Way Galaxy. The solid black lines show the positions of the Galaxy’s spiral arms. The colors indicate groups of objects belonging the same arm. The background is a simulation image.
Earth just got 7 km/s (~16,000 mph) faster and about 2000 light-years closer to the supermassive black hole in the center of the Milky Way Galaxy. But don’t worry, this doesn’t mean that our planet is plunging towards the black hole. Instead, the changes are results of a better model of the Milky Way Galaxy based on new observation data, including a catalog of objects observed over the course of more than 15 years by the Japanese radio astronomy project VERA.
VERA (VLBI Exploration of Radio Astrometry, by the way “VLBI” stands for Very Long Baseline Interferometry) started in 2000 to map three-dimensional velocity and spatial structures in the Milky Way. VERA uses a technique known as interferometry to combine data from radio telescopes scattered across the Japanese archipelago in order to achieve the same resolution as a 2300 km diameter telescope would have. Measurement accuracy achieved with this resolution, 10 micro-arcseconds, is sharp enough in theory to resolve a United States penny placed on the surface of the Moon.
Because Earth is located inside the Milky Way Galaxy, we can’t step back and see what the Galaxy looks like from the outside. Astrometry, accurate measurement of the positions and motions of objects, is a vital tool to understand the overall structure of the Galaxy and our place in it. This year, the First VERA Astrometry Catalog was published containing data for 99 objects.