During a retrograde loop of mars, would you expect mars to be brighter than usual in the sky, about average in brightness, or fainter than usual in the sky? explain.

If the comparison is made from the vision of the planets from the earth and the sun, different movements will be observed.

From the sun, all the planets are moving eastward with the background stars. However, from a mobile platform such as the terra, the planets that are in the farthest orbits that the earth seem to regress in some months of the year.

During this time interval, the planet approaches the sun and therefore the distance between the earth and Mars also decreases. This is optically reflected in the brightness of the planet, which generates a greater brightness in the sky.