It may not seem like it, but it is approaching two years now since New Horizons made its historic flyby of Pluto and its moons in July 2015. But even though it has been quiet since then, the mission continues, as the spacecraft is now preparing for its next flyby of another Kuiper Belt Object (KBO) on Jan. 1, 2019 – and now New Horizons has reached the halfway point between Pluto and the next target, called 2014 MU69. It’s another major milestone for a mission that gave us our first close-up views of the Pluto system, and revealed worlds utterly alien and unique in the Solar System.
Long after its incredible encounter with Pluto and its moons in 2015, the New Horizons spacecraft is continuing its journey deeper into the Kuiper Belt in the outer reaches of the Solar System. Mission scientists and engineers are now preparing for its next close flyby, of a smaller body called 2014 MU69, on Jan. 1, 2019. Along the way, New Horizons makes occasional slight course corrections to keep it on track, and now the spacecraft has just successfully completed its latest one.
Charon is Pluto’s largest moon and, despite being so cold and remote from the Sun, has been revealed to be a fascinating and active world, just like Pluto itself. Residing in the far outskirts of the Solar System, it had been expected that Charon – and Pluto for that matter – would be little more than frozen, dead worlds. But just like the rest of the Solar System, there were surprises waiting to be found. Thanks to the New Horizons spacecraft, we got our first close-up views of the Pluto system in July 2015. It soon became evident that not only were Pluto and Charon geologically active in the ancient past, but they perhaps still are in some ways even now. One of the most surprising findings was both Pluto and Charon likely had subsurface water oceans; while it is thought that Pluto’s is probably still liquid, Charon’s is likely completely frozen, and now additional evidence for its existence has been published by researchers.
Pluto, a tiny frigid world in the distant outskirts of the Solar System, has been full of surprises, as first revealed by the New Horizons spacecraft back in July 2015. Expected to be mostly a cold, geologically dead place, it has instead been shown to be quite the opposite. Yes, it’s bitterly cold of course, but New Horizons found ample evidence that it has also been geologically active in the past and in some ways still is. With tall mountains of solid water ice, ancient riverbeds carved by nitrogen rivers, vast plains, still-flowing glaciers of nitrogen ice, and possible ice volcanoes, Pluto is a wondrous world indeed. Another new finding makes it even more remarkable: evidence for a subsurface ocean of water. This had also been reported on previously by AmericaSpace, but the new update strengthens the case.
To say that the New Horizons mission has been a success would be a massive understatement; this first-ever spacecraft to visit Pluto has revolutionized our understanding of this distant, small world. Pluto and its moons are complex and active places, more so than thought possible by most scientists. Even though New Horizons flew past Pluto instead of orbiting it in July 2015, it still collected an enormous amount of information, which has taken more than a year to be sent back to Earth. That process is now complete, NASA just announced.
It has been 14 months since the New Horizons spacecraft flew past Pluto and its moons, but data still continues to come in, and new discoveries are still being made. The dwarf planet has surprised scientists by its geological activity, for the most part unexpected for such a small, cold body. Now two new results are adding to the mystery of Pluto: the detection of x-rays emanating from the surface and new evidence that Pluto “spray-paints” the north pole of its largest moon Charon a rusty red colour.
So-called “waterworlds” have been found to be surprisingly common in the Solar System – small icy moons which have ice crusts but oceans of liquid water below the surface. These include Jupiter’s moons Europa and Ganymede and Saturn’s moons Enceladus and Titan, and possibly others. These moons are cold and very far from the Sun, but heated inside by the gravitational pull of their giant host planets and/or radioactivity. Now there’s another Solar System body which, even more surprisingly, some scientists think has a subsurface ocean: Pluto.