https://www.sott.net/article/400526-Heav...lion-years
The Sagittarius dwarf galaxy was cosmically cannibalized by the Milky Way galaxy... the two are 'merging', a process of passing through each other. When galaxies pass through each other, apparently there's so much space between all the stars and other bodies that they don't usually collide with anything.
Some even say that we are actually from the Sagittarius dwarf galaxy, a theory I have been very interested in for many years, as I feel it makes a lot of sense.
https://en.wikipedia.org/wiki/Sagittarius_Stream
http://annesastronomynews.com/annes-pict...al-galaxy/
https://www.esa.int/spaceinimages/Images...l-sky_view
http://www.esa.int/Our_Activities/Space_...ulent_life
https://en.wikipedia.org/wiki/Sagittariu...dal_Galaxy
https://astrobites.org/2017/06/20/galact...us-stream/
