Earth is 2,000 light years closer to supermassive black hole at the center of our galaxy than we thought
A new map of the Milky Way by Japanese space experts has put Earth 2,000 light years closer to the supermassive black hole at the center of our galaxy.
This map has suggested that the center of the Milky Way, and the black hole which sits there, is located 25,800 light-years from Earth. This is closer than the official value of 27,700 light-years adopted by the International Astronomical Union in 1985, the National Observatory of Japan said.
What's more, according to the map, our solar system is traveling at 227 kilometers per second as it orbits around the galactic center -- this is faster than the official value of 220 kilometers per second, the release added.
These updated values are a result of more than 15 years of observations by the Japanese radio astronomy project VERA, according to an announcement released Thursday from the National Observatory of Japan. VERA is short for VLBI Exploration of Radio Astrometry and refers to the mission's array of telescopes, which use Very Long Baseline Interferometry to explore the three-dimensional structure of the Milky Way.
Because the Earth is located inside the Milky Way, it's difficult to step back and see what the galaxy looks like. To get around this, the project used astrometry, the accurate measurement of the position and motion of objects, to understand the overall structure of the Milky Way and Earth's place in it.
The black hole is known as Sagittarius A* or Sgr A* and is 4.2 million times more massive than our sun. The supermassive hole and its enormous gravitational field governs the orbits of stars at the center of the Milky Way. Reinhard Genzel and Andrea Ghez earned the 2020 Nobel prize for physics for its discovery. There are several types of black holes, and scientists believe the supermassive ones may be connected to the formation of galaxies, as they often exist at the center of the massive star systems -- but it's still not clear exactly how, or which form first.
More precise approach
In August, VERA published its first catalog, containing data for 99 celestial objects. Based on this catalog and recent observations by other groups, astronomers constructed a position and velocity map. From this map, the scientists were able to calculate the center of the galaxy, the point that everything revolves around.
VERA combines data from four radio telescopes across Japan. The observatory said that, when combined, the telescopes were able to achieve a resolution that in theory would allow the astronomers to spot a United States penny placed on the surface of the Moon.
To be clear, the changes don't mean Earth is plunging toward the black hole, the observatory said. Rather, the map more accurately identifies where the solar system has been all along.