Each Voyager spacecraft carries a "postcard" designed to be understandable to any aliens that might someday encounter it. On the "postcard," scientists pinpointed the location of Earth by triangulating it between pulsars. Why did the scientists choose pulsars rather than some other type of star?

A)Pulsars are very bright and therefore easy to find.
B)Several pulsars are located within a dozen light-years of our solar system, making them useful for finding our solar system.
C)We're pretty sure that aliens will have only radio telescopes and not optical telescopes, so they'll have a better chance of seeing pulsars than ordinary stars.
D)Pulsars are easy to identify by their almost perfectly steady periods of pulsation.

D)Pulsars are easy to identify by their almost perfectly steady periods of pulsation.

Explanation:

Neutron stars are the stars which do not have enough mass to turn into a black hole. They have very high density of mass. As the star core collapses as the neutron star is smaller in size the speed at which it rotates increases. This happens as the angular momentum is conserved. Some neutron stars eject electromagnetic radiation from their poles. The ejection takes place in precise intervals of time.

This makes it very easy in order to locate the position of one's planet in the universe.

So, the scientists chose pulsars as they are easy to identify by their almost perfectly steady periods of pulsation.

the area between the graph and the t axis