Final answer:
To determine when a comet will reach its furthest point from the Sun after being closest in 1982, the specific comet's orbital period is required; without it, a prediction cannot be made accurately.
Step-by-step explanation:
If a comet last came closest to the Sun in 1982, when it will reach its furthest point from the Sun, also known as the aphelion, depends on the comet's orbital period.
The point of closest approach to the Sun is called the perihelion. Since comets follow elliptical orbits, we would need to know the specific orbital period of the comet to determine when it will arrive at its aphelion.
Comets like Halley have their orbital periods well-studied and documented. For example, historical records show that Comet Halley has been observed on every perihelion passage since 239 BCE, at intervals ranging between 74 to 79 years, which is influenced by the gravitational pull from other planets in the solar system. However, for a hypothetical comet with no given period, it is impossible to predict its aphelion without additional data.