Dwarf planet Eris, similar in size to its better-known cosmic cousin Pluto, has remained an enigma since being discovered in 2005 lurking in the solar system's far reaches. While Pluto was explored by NASA's New Horizons spacecraft during a 2015 flyby, Eris - about 40% further from the sun - has never been visited.
I find it fascinating how astronomers can figure out the amount of ice and rock, the planet’s history, its temperature, etc. just by pointing a telescope at it and basically measuring the color of the light.
All nine blurry pixels of it.