A TRULY BIG map: The Milky Way Galaxy

Recent notices about the completion of the biggest map of the Milky Way Galaxy, consisting of 200,000 images, will surely be an interesting and informative reading for the subscribers to this data blog.

https://www.cnet.com/science/the-biggest-map-of-the-milky-way-ever-created-is-here/

“Using the VISTA telescope, the European Southern Observatory put 13 years of work into the map”, which covered 420 nights of observation. The map takes up 500 TB and contains 1.5 billion objects. Yes, billion.

To view the map, see this site: https://archive.eso.org/scienceportal/home (screen capture below). Spend some time zooming in on sections, trying the filter tools, examining the metadata, and exploring the attribute table. Try one of the zip file options and see what results. For more about the project and for more fascinating images, see: https://www.cnet.com/science/space/building-the-ultimate-milky-way-map-heres-what-scientists-have-so-far/

All of this makes me wonder about the coordinate space that objects such as the Milky Way are surely mapped in to keep track of their position and their movement. Where is the origin of such a coordinate space–is it the Earth’s position in the cosmos or some other location? What are the axes for such a coordinate space? Doesn’t such a coordinate space necessarily continually expand given what we know about the known universe?

Another thing I wonder about: Is such a map ever really complete? I am sure there will be increasing detail, and new discoveries, added, just like most other maps that the community creates–they’re not really ever ‘completed’. Indeed, the above article points out that, “The Milky Way is estimated to have anywhere from 100 billion to 400 billion stars and likely as many planets. At 1.5 billion objects, the map represents only a small slice of the galaxy.”

But the map is still mighty impressive in its current state and touches on the big data, resolution, and other themes of this blog.

–Joseph Kerski