In 1974, a radio message was sent out from the Arecibo observatory in Puerto Rico towards a globular cluster, 21,000 light-years away. Approximately how far has this message gotten as of today?
A) It's just beyond the Neptune in our solar system
B) It's just passing through the Oort cloud surrounding our solar system
C) It's just passing stars that are close neighbors to the Sun in the Milky Way
D) It's almost at the center of the Milky Way
E) It's already arrived at the globular cluster

Question

Quizplus · Accepted Answer

The message has been traveling for about 49 years, which means it has traveled 49 light-years. This distance is enough to pass through the region of stars that are close neighbors to the Sun in the Milky Way.

In 1974, a Radio Message Was Sent Out from the Arecibo