The link is to a fascinating article from the Smithsonian Institution's July 'Air & Space' magazine, about NASA's current New Horizons mission to Pluto and the Kuiper Belt. The fastest spacecraft ever built is on its way to explore the outer reaches of the solar system, including objects not yet discovered that will (hopefully) be located while it's in transit! Even the origin of the 'Planet X' meme gets a mention.
Where the Wild Things Are