Every 248 years, something remarkable happens in the life of Pluto. This distant and enigmatic dwarf planet completes one full orbit around the Sun, a journey that takes nearly two and a half centuries to complete. Let’s delve into the fascinating events and characteristics that occur during this lengthy orbital period.
First and foremost, it is important to note that Pluto’s orbit is quite different from the familiar, relatively flat plane traveled by the eight planets in our solar system. Instead, Pluto’s orbit is inclined at an angle of 17 degrees relative to this plane. This inclination gives Pluto a unique perspective as it travels around the Sun, allowing it to occasionally cross the paths of other planets in its orbit.
Furthermore, the shape of Pluto’s orbit is more elliptical, or oval-shaped, compared to the nearly circular orbits followed by the planets. This means that Pluto’s distance from the Sun varies significantly throughout its orbit. At its closest point to the Sun, known as perihelion, Pluto is about 3.67 billion miles (5.91 billion kilometers) away. At its farthest point, known as aphelion, it can be as distant as 4.67 billion miles (7.50 billion kilometers) from the Sun.
The combination of Pluto’s inclined orbit and its elongated shape leads to some remarkable occurrences during its 248-year journey around the Sun. For instance, there are periods when Pluto is closer to the Sun than Neptune, which is the eighth and farthest known planet from our star. This happened between the years 1979 and 1999, allowing astronomers and space enthusiasts to witness a unique alignment of these two distant worlds in our solar system.
Additionally, due to its elliptical orbit, Pluto experiences significant changes in its climate and surface conditions over the course of its long orbit. As it moves closer to the Sun, the dwarf planet’s icy surface begins to sublimate, transforming from a solid directly into a gas. This process causes changes in its atmosphere, leading to the formation of a thin atmosphere composed mainly of nitrogen, with traces of methane and carbon monoxide.
Moreover, as Pluto reaches its closest approach to the Sun, the increased solar radiation causes its frozen nitrogen and methane to vaporize, creating temporary, thin atmospheres. These atmospheres can reach a height of over 100 kilometers (62 miles) and are thought to play a role in shaping the planet’s surface over time. However, as Pluto moves away from the Sun, the gases condense and freeze once again, returning the dwarf planet to its frigid, barren state.
Interestingly, the elliptical orbit of Pluto also affects the length of its seasons. While Earth experiences four distinct seasons each year, Pluto’s seasons last for multiple decades. This is due to the planet’s slow progression around the Sun, which causes it to spend extended periods in different regions of its orbit, leading to prolonged periods of either summer or winter.
The completion of one orbit by Pluto every 248 years is a momentous event in the life of this dwarf planet. Its inclined and elliptical orbit brings about unique interactions with other planets, variations in climate and surface conditions, and the formation of temporary atmospheres. Understanding these characteristics not only enhances our knowledge of Pluto but also deepens our understanding of the diverse and complex nature of our solar system.