Our Part of the Milky Way Is Four Times Bigger Than We Thought

Radio astronomers announce a major new finding that changes how scientists view the structure of our home galaxy.

The section of the Milky Way galaxy that contains our solar system is four times larger than astronomers previously thought.

Published in the journal Science Advances this week, a new study reported that our surrounding area of stars, gas, and dust—called the Local Arm, Orion Spur, or Orion–Cygnus Arm—is actually about 20,000 light-years long.

The immediate implications are that the galaxy is actually a little more symmetrical and regular than scientists previously thought, says one of the study's co-authors, Mark J. Reid of the Harvard-Smithsonian Center for Astrophysics. Although a better understanding of our galaxy's structure doesn't necessarily mean gravity or other forces acting on us are different from what we expect, it could help us better understand large-scale features

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