On July 14, 2015, the New Horizons spacecraft arrived at dwarf planet Pluto. For the first time we got to see pictures of this mysterious, icy world. The space photo of the week captured New Horizons fifteen minutes after its closest approach and is, in our opinion, one of the most beautiful images of Pluto ever.
The photo shows everything: glaciers, high mountain peaks, fog patches and ice plains. The most famous ice sheet can be seen on the right. This is Sputnik Planum, also known as the heart of Pluto. Sputnik Planum is no older than ten million years and is covered with nitrogen ice. It is still a mystery how the surface of this part of Pluto is regularly renewed. Does ice rise from the bottom and replace the older ice? Or is there ice volcanism, causing the ice to melt from time to time? Astronomers aren’t sure yet.
Click on the photo to view it in high resolution.
Several mountains can be seen on the left. This area is called Tenzing Montes. They are the highest mountain peaks on the distant dwarf planet. The steep ice peaks have slopes of forty degrees or even more. The highest peak is about six kilometers high, which is comparable to Kilimanjaro in Kenya. Pluto’s mountains are probably made up of water ice. Methane and nitrogen ice are not possible, because then the mountains would collapse.
Above you see a detail of the larger photo. The mountains of Tenzing Montes can be seen in the foreground, while a little further to the rear, the peaks of Hillary Montes can be seen. Named after explorer Sir Edmund Hillary, these mountains rise about 3.5 kilometers above Pluto’s surface. In terms of height, the mountains are comparable to Mount Fuji (Japan). The area in this photo has a diameter of 380 kilometers.
Towards interstellar space
After the flyby of Pluto and Charon, New Horizons traveled to Arrokoth (better known as Ultima Thule). This Kuiper Belt object was photographed by the spacecraft on January 1, 2019. At the moment, New Horizons continues at a speed of almost 53,000 kilometers per hour. This makes New Horizons not the fastest space probe to leave our solar system, because Voyager 1 holds that record firmly (61,146 kilometers per hour). Voyager 1 has in the past had a powerful gravitational pendulum from the large planets Jupiter and Saturn.
The agenda? Still pretty empty!
There are no plans for New Horizons to visit any other Kuiper Belt objects. There is not enough fuel to travel to a known object. But… who knows, maybe in the coming years a mysterious distant world will be discovered that lies ‘en route’. In that case, New Horizons could be used to take pictures. We wait in suspense.