Actually we cannot see far (other galaxies, early galaxies, quasars) in some parts of the sky because we are in our own galaxy plane [1], so stars, but mostly gas and dust between them obscure significant portion of our field of view [2]. So it is not flat 90 degrees, but roughly two cones with 90 degrees openings in Milky way's plane perpendicular directions.
In a few more millennia, our arm of the Milky Way will spin around so that we are able to the other side. We should be able to get some decent parallax measurements to distant objects at that time as well.
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Actually we cannot see far (other galaxies, early galaxies, quasars) in some parts of the sky because we are in our own galaxy plane [1], so stars, but mostly gas and dust between them obscure significant portion of our field of view [2]. So it is not flat 90 degrees, but roughly two cones with 90 degrees openings in Milky way's plane perpendicular directions.
1. https://scitechdaily.com/gaia-spacecraft-discovers-parts-of-...
2. https://www.darkenergysurvey.org/supporting-science/large-sc...
In a few more millennia, our arm of the Milky Way will spin around so that we are able to the other side. We should be able to get some decent parallax measurements to distant objects at that time as well.
About 57,500 more millennia till we get that quarter turn of our galactic orbit
So that's what, 2 days on the Cosmic Calendar?
https://en.wikipedia.org/wiki/Cosmic_Calendar