Astronomy Practice Exam

In the context of measuring distances in triangulation, what is the baseline?

1. The angle of observation from a fixed point

2. The measurement of distance between two known points

3. The radius of a star

4. The length of a light year

The correct answer is: The measurement of distance between two known points

In triangulation, particularly in the context of astronomy and measuring distances to celestial objects, the baseline refers to the distance measured between two fixed points that are known. This baseline is crucial because it serves as one side of a triangle formed by the two observation points and the distant celestial object. By knowing the baseline and the angles observed from each point, astronomers can apply trigonometric principles to calculate the distance to the object in question. To elaborate, the longer the baseline, the more accurate the measurements can be, as it reduces the potential for errors in angle measurement and increases the overall accuracy of distance calculations. The ability to establish a precise baseline is fundamental in various methods, such as parallax measurements, where the apparent motion of the object against a more distant background is observed from two different locations. The other options pertain to different concepts, such as angles of observation, specific measurements in astronomical units (like light-years), or physical characteristics of stars, which do not directly relate to the fundamental concept of a baseline in the triangulation process.