Pluto, the former ninth planet of our solar system, has always been an object of fascination for astronomers. Even after being reclassified as a dwarf planet in 2006, it remained a subject of curiosity for space scientists. NASA’s New Horizons probe, launched in 2006, reached Pluto after nine years of traveling through space. The images sent back by the spacecraft led to some exciting new discoveries and intriguing questions. One of the most significant findings is the presence of possible cryovolcanism on Pluto’s surface, which hints at the possibility of an ocean and perhaps even life on the far-flung world.

The Surface of Pluto: More Than Meets the Eye

Pluto is an icy world with a heart of frozen nitrogen and carbon monoxide ice. The New Horizons’ pictures have revealed something completely astonishing and unexpected that has never been seen on any other planet in the solar system. The images of Pluto’s surface have shown many bumpy volcanoes raised to different heights. And surprisingly, unlike the rest of the planet, there were no impact craters from asteroids or meteors nearby. In addition, there was no evidence of plate tectonics activity that plays a crucial role in mountain formation on Earth. All these factors together hinted that this surface was formed after a geologic disturbance, possibly a volcanic eruption, that took place recently, definitely within the past 2 billion years.

Two Volcanoes: Wright Mons and Piccard Mons

Talking about Pluto’s volcanic features, two peaks towering over the dwarf planet’s surface have puzzled planetary scientists for years. The first one is a mountainous feature called Wright Mons. This surface entity is around 150 km wide, bulges out up to nearly 5 km above the surface, and has a central depression that is almost 50 km across. Then the second feature, named Piccard Mons, rises to nearly 7 kilometers and has a width of around 225 kilometers. You would be surprised to know that even though Pluto’s diameter is just one-sixth of Earth’s, this volcano’s total volume is similar to that of Hawaii’s Mauna Loa, one of the biggest volcanoes on our planet.

These gigantic surface features sit at the southwest edge of the Sputnik Planitia ice sheet, which is the lighter region on the left of the famous heart-shaped feature on Pluto, and were first spotted when the New Horizons spacecraft flew past the planet in July 2015. This sheet is characterized by an ancient impact basin nearly 1,000 km wide and is dominated by folds and rises that appear like wrinkles over a smooth cover of ice. There also exist several volcanic domes in this region, with most of them tending to merge into a bigger dome.

Cryovolcanism on Pluto

After carefully analyzing the images captured by the New Horizon, researchers speculate that the formation of such a terrain must have been fueled by multiple eruption sites located near each other. And possibly, the material ejected during the resultant cryovolcanic eruptions coated the entire region with layers of ice. A detailed study also reveals that the surface material in this region is primarily water ice and not nitrogen or methane ice, as usually found in other younger parts of the planetary surface. And this further solidifies the possibility of cryovolcanic activity.

For volcanoes to be active, a constant heat source must exist to drive the eruptions. But as far as Pluto is concerned, neither the planet’s neighbors are strong enough to generate sufficient tidal and gravitational forces to warm its interior, nor the amount of rocky material present inside Pluto’s core is enough to generate heat from radioactivity. Considering all the points, the only plausible scenario is that the dwarf planet still has leftover heat from its formation trapped within it, most likely in a deep water ocean beneath its icy crust.

Hidden Ocean on Pluto

Even other icy bodies in the solar system, such as Saturn’s moon Enceladus and Jupiter’s moon Europa, are known to contain such oceans. In addition, Enceladus has shown evidence of regular cryovolcanism by spewing icy material out into space and replenishing one of Saturn’s rings. Therefore, it is highly possible that Pluto has a hidden ocean that may be playing a role in the planet’s cryovolcanism.

Life on Pluto?

The discovery of cryovolcanism and a possible hidden ocean on Pluto has raised the question of whether life could exist on the dwarf planet. While the surface temperature of Pluto is an average of almost -240°C, which is too cold to sustain life as we know it, the presence of a hidden ocean beneath the icy crust could provide a warm and stable environment that may support life. Moreover, the water in the hidden ocean could contain organic molecules, the building blocks of life, which may have been delivered to Pluto by comets or asteroids.

In addition, volcanic activity could provide the necessary energy and nutrients for life to exist. However, it is important to note that the existence of a hidden ocean on Pluto has not yet been confirmed, and even if it does exist, the chances of finding life on the dwarf planet are still slim. Nevertheless, the discovery of cryovolcanism and a possible hidden ocean on Pluto has opened up new avenues for research and exploration, and it will be exciting to see what future missions to the dwarf planet will reveal.

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