For 85 years Pluto was barely more than a dot in a telescope. Then in 2015 NASA's New Horizons flew past after a nine-year, three-billion-mile journey and revealed a 1,000-kilometer heart-shaped nitrogen glacier and a surface impossibly young — and the probe is still going.
NASA’s New Horizons Explained: NASA’s New Horizons spacecraft, which left Earth nearly two decades ago and has transformed scientific understanding of Pluto, has entered into the longest hibernation period of its journey so far.
The probe made histor... [4567 chars]

