Using a technique known as very long baseline interferometry (VLBI), in which the signals received by two radio telescopes located on different continents are combined as if they were a single radio telescope, astronomers can resolve two objects separated by only 0.00001 second of arc. What is the smallest detail we can see in a quasar 15 billion light-years away using this kind of interferometer?
A)0.7 ly
B)44 ly
C)2400 ly
D)150,000 ly

Question

Quizplus · Accepted Answer

The smallest detail that can be resolved is calculated using the angular resolution formula. Given the resolution of 0.00001 second of arc for VLBI, and considering the distance to the quasar (15 billion light-years), the smallest detail observable would be approximately 0.7 light-years. This is derived from converting the angular resolution into a linear scale at the distance of the quasar.

Using a Technique Known as Very Long Baseline Interferometry (VLBI)