Year of 2017

Pluto’s north pole

Pluto may no longer be considered a full-fledged planet, but it’s still the largest of our solar system’s dwarf planets and holds plenty of mysteries waiting to be discovered. Because it’s so far away—about 40 times as far from the sun as Earth is—scientists knew relatively little about Pluto until the New Horizons spacecraft reached it in 2015. In a flyby study, the craft spent more than five months gathering detailed information about Pluto and its moons, while taking photographs like those that make up this composite image.

Pluto is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune. It was the first Kuiper belt object to be discovered. Pluto was discovered by Clyde Tombaugh in 1930 and was originally considered to be the ninth planet from the Sun. After 1992, its status as a planet was questioned following the discovery of several objects of similar size in the Kuiper belt. In 2005, Eris, a dwarf planet in the scattered disc which is 27% more massive than Pluto, was discovered. This led the International Astronomical Union to define the term “planet” formally in 2006, during their 26th General Assembly. That definition excluded Pluto and reclassified it as a dwarf planet.
Radius: 736 miles (1,185 km)
Surface area: 6.43 million sq miles (16.65 million km²)
Orbital order: 9
Orbital period: 247.84 years
Gravity: 2.16 feet/s² (0.66 m/s²)
Star system: Solar System
PLUTO - NEW HORIZONS - July 14, 2015
PLUTO – NEW HORIZONS – July 14, 2015 ORIGINAL IMAGE DESCRIPTION: Four images from New Horizons’ Long Range Reconnaissance Imager (LORRI) were combined with color data from the Ralph instrument to create this global view of Pluto. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 280,000 miles (450,000 kilometers) away, show features as small as 1.4 miles (2.2 kilometers), twice the resolution of the single-image view taken on July 13 [2015]. UPLOADER NOTES: The north polar region is at top, with bright Tombaugh Regio to the lower right of center and part of the dark Cthulhu Regio at lower left. Part of the dark Krun Regio is also visible at extreme lower right. The original NASA image has been modified by doubling the linear pixel density and cropping.