NASA made history this week, once again, when the project New Horizons, launched 9 years ago, reached the ‘ex-planet’ Pluto and its surrounding moons. Ever since it has arrived, it’s been sending us information from there, and putting it lightly, it has been a rollercoaster of emotions.
Scientists previously believed Pluto to be a calm, inactive dwarf planet; just a mass of ice and frozen gases floating around the Solar System. But defying all these expectations, Pluto seems to be very geologically active, actually similar to Earth, (or rather, one of Neptune’s moons, since it has a large ice mantle).
The clues that point to this surprising conclusion are many. For one, there are areas with no signs of craters caused by asteroid collisions, which would be impossible unless these sections are relatively new, as they would be if they had been formed recently by geological activity. There are also fault lines and rift valleys, both characteristic features of tectonic movement.
However, scientists are still puzzled as to how these movements are brought about. In Earth, tectonic movements happen because of the melted rock in the core of the planet, but this is not possible in Pluto, so a popular theory suggests that since it is filled with radioactive material (like most astronomical bodies), this somehow produces enough energy to heat up the surface of Pluto and causes the movement of large amounts of ice that act as tectonic plates.
But don’t think this trend of unexpectedness stops at Pluto. Its largest moon, Charon, is not far behind. It also displays signs of being geologically active, as it has deep canyons and very smooth expanses.
Since many new areas in Pluto and Charon have been true wonders, scientists have decided to give them appropriate names. The most famous one, unofficially nicknamed ‘The Heart’ because it is heart-shaped, is now probably going to be known as Tombaugh Regio in honour of Clyde Tombaugh, the discoverer of Pluto in 1930. Another feature is a plane made of ice, which shows troughs at regular intervals, and has been dubbed the Sputnik Planum, in honour of the first spaceship. The Norgay Mountains are named after the first Sherpa to climb Mount Everest, and are a range of 3300 meter-high mountains made entirely of frozen ice which behaves like rocks. Astronomers also seem to be huge fans of the Lord of the Rings trilogy, as they have named a feature in Pluto ‘Balrog’, a monster from this series, and a dark region in the pole of Charon is being called Mordor.
The mission also offered an opportunity to accurately measure Pluto’s diameter for the first time. The results show that it is 2.370 km large, possibly the largest of the five recognized dwarf planets in the Solar System.
Although the official flyby has ended, New Horizons’ adventures are not over. All this baffling information it has sent us only represents about 2% of all the data it has collected, so we can still expect many surprises from this mission for about 16 months as the rest comes in. And after the visit to Pluto, it is going to fly to the Kuiper Belt, a zone beyond the planets full of small icy bodies that may contain some interesting information as to how the Solar System was formed.