Why did scientists choose pulsars rather than some other type of star for triangulating the location of Earth on the Voyager spacecraft postcard?

Pulsars were chosen for triangulating Earth's location because they exhibit an almost perfectly steady period of pulsation. This characteristic is essential for precise navigation and positioning. The regularity of their pulsations allows for accurate timing measurements, which can be used to determine the distance to the pulsar with great precision. This stability facilitates a reliable way to reference Earth's position in space, making the pulsars effectively act as cosmic lighthouses.

While pulsars do emit radio waves, they are not the only stars that do so, and this characteristic alone does not contribute to their suitability for triangulation. The brightness of pulsars is not a factor because many of them are not particularly bright when viewed from Earth; instead, it is their steady pulse that is the key feature. Additionally, while pulsars do have fixed positions in the Milky Way, this is not the primary reason for their selection in this specific context, as the consistency of their pulsation periods is what ultimately allows for accurate distance measurements.