How can one claim, or locate, a specific part of outer space ?

http://www.spacefuture.com/archive/real_property_rights_in_outer_space.shtml
especially “territorial claims section”..very interesting topic!

all you need are reference points.
for a space based coordinate system you could for example use the sun as a point of origin, the normal vector of the two dimensional ellipse of earth’s orbit around the sun as the z axis, and, for example, the vector established by the sun and earth on january 1st 0:00 as the x-axis, have the y axis perpendicular to both the already established z and x axes, and you have your decidedly sol-centric space based coordinate system.

You can do the same for the galaxy, with the galactic plane’s normal vector as Z, and the connection between the galactic core and earth as X, plus the constructed Y based on X and Z. Alternatively you could just assign an arbitrary X axis.

Space is constantly expanding, so any coordinates you use would be affected over time. It would be a bit like identifying coordinates on a tree, then going back 20 years later and trying to find the same part of tree at the same coordinates.

As I understand it, space is not nothing, it is as real as stone, it can be bent and shaped, almost like you can shape clay, and it is growing, very fast. So I guess you would need to know exactly how it grows, to figure out how your system is going to work.

It is like the metaphor, you can’t ever put your foot in the same river twice. You could just etch out some coordinates, to pinpoint an exact location or 3D area/shape/place, but if you went there, left, and then went back, while you would be in empty space, you would no longer be in the same space, yes you would be in space, yes it would be in the same place, but no it would no longer be the same tangible space that you laid claim to, that could be bent and manipulated and filled.

So, you would probably be better off, laying claim to the contents of a coordinate, rather than lay claim to space. Otherwise, it would be like having a pint of water, and trying to figure out who owns the water molecules that were in a specific location 15 minutes ago, and how now to find them.

You could do a co-ordinate system from Galactic Zero (center of the galaxy). Then contact the UN to get your co-ordinate system recognized, then claim a portion of your choosing. Just not the moon. Already claimed by the US of A.

If you want to be totally absurd, like giving a present to a gf/bf that you no longer have anything meaningful with, name a star after them and receive its coordinates et cetera for a price here star registry

The Sun is not in a set position, nor is the galaxy, which means your location, if you want a fixed point, could not be located using moving positions.