Final answer:
Planets are visible from Earth when they reflect sunlight; their brightness is not solely dependent on proximity. Far planets can appear brighter if they reflect light from highly luminous stars. Technological advancements in astronomy have made it possible to directly image a few of these distant planets.
Step-by-step explanation:
The brightness of planets as seen from Earth does not necessarily correlate to their proximity to our planet. We see nearby planets because they reflect the light of our Sun; their visibility depends heavily on this reflected sunlight. Planets that are far from Earth can often be brighter because they are reflecting light from stars that emit vast amounts of energy. This makes them visible even at great distances. However, seeing planets around other stars is a tremendous challenge due to the overwhelming glare of these stars, which usually outshines the reflected light from their planets. The brightest stars in our sky are not always the closest, but they do emit large quantities of energy, allowing them to shine brilliantly irrespective of distance. Advanced technology in telescopes has enabled us to directly image a few of these distant planets, but the task is formidable due to the faintness of the planets in comparison to their parent stars.