Saturday August 24, 2019, marked a vexing anniversary for planetary scientists. It was 13 years to the day that Pluto's official definition changed — what was once numbered among the planets of the Solar System was now but a humble dwarf planet.
NASA's New Horizons spacecraft is far from done making waves in cosmic discoveries. But to understand where New Horizons is going next it's important to know why Pluto was selected for a flyby mission by NASA, phys.org wrote.
The nitrogen ice glaciers on Pluto appear to carry an intriguing cargo: Numerous, isolated hills that may be fragments of water ice from Pluto's surrounding uplands. These hills individually measure one to several miles or kilometers across, according to images and data from NASA's New Horizons mission.