The New Horizons unmanned space probe.
Image: NASA.

In 2006 on this date, the New Horizons spacecraft was launched; this was the last robotic mission to an unexplored “planet” in our solar system. In 2015 it sent back data and close-up images of the “dwarf planet” Pluto, and in early 2019, data and closeup images of the Kuiper Belt object Arrokoth. More information about the New Horizons mission may be found at NASA’s pages here.