17 June 2021

Where we are in space

Here's something you don't see all the time that gives a little perspective of "where we are".  The photo is a spiral galaxy more or less similar to the Milky Way seen almost exactly edge on. Think of it as a stand-in for our Galaxy. Then the diagram, obviously not at all to scale, depicts the angle of the plane of the solar system, about 66° to the plane of the Galaxy. (In reality, the Solar System would be invisibly small at this scale, as the Sun is but one of nearly 300 billion stars in the Galaxy.

  We are about 27,000 light years from the center, and the disk as seen in this image would be about 85,000 light years in diameter in the Milky Way. The Sun is located in a spur of one of the spiral arm, and its orbit and position with respect to the central "bar" (the MW is a "barred spiral" type galaxy) is shown in the image below.