New Horizons’ Encounter With Pluto — Our Solar System’s Missing Link

In our modern world of extremes, what’s just happened over 4.5 billion miles away — at what was once considered the edge of the solar system — is something else. On the morning of July 14, NASA’s New Horizons interplanetary space probe hurtled past the Plutonian system at over 32 thousand miles an hour, executing the most exquisitely timed and delicately balanced pirouettes to ensure every last second of precious time was used to capture as much scientific data as possible of Pluto and its five known moons. Instruments painstakingly designed to operate in the brutally hostile environment of deep space took spectra images, sampled dust and space plasma and deliberately had their radio signals blotted out by Pluto and its moon Charon so as to directly probe their primitive atmospheres. All of this was done remotely, as it takes almost five hours for radio signals to travel out to the Smart car-sized spacecraft; and so for the New Horizons team, it was the longest possible wait until the probe finally oriented its modest antenna dish back home and started sending back its precious cargo.

And what cargo it is. Since its serendipitous discovery by the young American astronomer Clyde Tombaugh in the cold winter of 1930, Pluto has kept its secrets to itself, its staggering remoteness and small size confounding our attempts to make sense of what it is, and why it’s there. These are simple questions — like all the best questions in science should be — yet ironically, these are always the hardest to answer. Pluto has always been regarded as the runt of the planetary litter. The inner planets (Mercury, Venus, Earth and Mars) are small, rocky and compact; the outer planets are giants of swirling gas and ice (Jupiter, Saturn, Uranus and Neptune). They all orbit —> Read More