What is a baseline in astronomy?

It took me some time to figure out the answer to this question, referencing multiple websites, books, and other sources before I was able to finally scratch out: stars, planets, black holes, or what?

A baseline, to put it very simply, is a minimum point that is used for comparisons. In our universe, the earth can be thought of as a starting point with respect to the sun, moon, and body; however, astronomers use satellites and telescopes in this process to determine the distance between two bodies or the size of a body.

I hope that was useful. :-)

In astronomy, a baseline refers to the distance between two telescopes or antennas used in interferometry to measure the angular separation and properties of celestial objects. It allows astronomers to achieve higher resolution by combining the signals received from different telescopes or antennas.