Jupiter will be close to the Earth and located exactly opposite to the Sun, which says the Earth will be between the two. The giant planet will be brightly illuminated by the Sun’s light just like the full Moon. It will be brighter than any other time of the year. Opposition is actually same as elongation, just named differently. When the angle between the planet and the Sun, is 180 degrees which means completely opposite to the Sun as seen from an observer on the Earth (however because of the huge Earth we can’t actually see them opposite to each other). So, another way to understand this elongation is the brightness of the planet that tells the presence of the Sun just opposite, illuminating it. If you see through Binoculars, you cannot just observe Jupiter but also, its four largest moons, Ganymede, Io, Callisto and Europa.

Elongation is generally defined as the angle between the two planets, or a planet and the sun, or a planet and the moon or the moon and the sun as seen by an observer on the Earth. Venus at elongation suggests the angle between Venus and Sun, and eastern elongation concludes the position of Venus in East of the Sun. Which means the Planet Venus is clearly seen after the sunset in the evening sky in the direction in which the sun sets i.e. west as seen from the Earth.