The Pluto encounter of July 14, 2015

Setting the Stage

The revealing of the outer Solar System is a process of Humanity extending its senses and awareness in greater detail and into further depths. The outer planets have a curious name relationship with ongoing discoveries of new elements. The first planet since antiquity to be recognized was discovered in 1781 by Sir William Herschell. It was soon given the name of the Greek deity of the skies, Uranus' (politely pronounced YOURinus). In 1789 element 92 was discovered, and given the name 'Uranium'. The discovery within the insensibly minute realms of nature was thus celebrated with a homage to the revealing of natures vastness. After a competition between nations, almost like a premonition of the later space race, another expected world was discovered by Johanne Galle of Berlin Observatory in 1846. It was named 'Neptune' for the Roman version of Poseidon, the Greek deity of water of the springs and the high seas. The next element naming didn't happen until 1940 when element 93 was named 'Neptunium'. The twentieth century made systematic sky surveys possible by telescopes equipped with cameras. People tried to search again for a large outer planet suggested to exist beyond the known worlds. Percival Lowell, with a fortuitous combination of science and wealth, had an observatory built in the hills overlooking Flagstaff, Arizona. There he would pursue his passions for looking for 'planet X' and for studying Mars

After Lowell's death in 1916 a renewed search using a new dedicated telescope was begun in 1929, conducted by newly hired 23 year astronomer Clyde Tombaugh. After a tedious search, on February 18, 1930 when comparing photos taken some time apart of the same part of the sky a moving dot revealed itself among the many stars. This quickly proved itself to be a new planetary body orbiting in then unknown depths of space. The discovery announcement was made March 13, the birthday of Lowell. Answering a public appeal for name suggestions, an 11 year old Oxford schoolgirl named Venetia Burney nominated 'Pluto', the deity ruling over the realm of the Underworld.

The next element to be christened was In 1941 Element 94 was named 'Plutonium', after this distant world. In a quirk of fate this very substance would one day enable the revealing of the deep secrets of the very world it was named after.

Again Flagstaff featured in revealing the Pluto system when by June 22, 1978 the photography improved enough to barely detect the nearby Moon. James Christy's discovery at the U.S. Navel Observatory was named 'Charon' after the god that ferried the souls of the dead across the waters to the underworld. The name is pronounced, according to the family, 'Shar-on' because Christy chose the name with his wife Charlene in mind.

A quick summary of Pluto

Pluto is a distant renegade world with an orbit very tilted as well as varying in its orbital distance from the Sun. A Pluto year is 248 of our years long. Pluto is 1472 miles across, or 2370 kilometers, in diameter as compared with that of the Earth, 7,918 miles and 12,742 km and the Moon, 2,159 miles or 3,475 km. Until Pluto's moon Charon was discovered the Earth/Moon system held the record of the largest moon in relation to the primary planet, our Moon being slightly over one quarter Earths diameter. Charon however is about 757 miles in diameter or 1208 km, making it slightly over half the size of Pluto. Pluto and Charon eternally face each other at the same locations, being tidally locked in a spinning embrace. Pluto is thought to be 60-70 percent rock and the rest ices. Charon's composition ratio is nearly inverted, more ice than rock.

The cold is beyond human perspective, about -382 degrees Fahrenheit or -230 degrees Celsius. Depending on where in its orbit one is, the distant Sun shines its feeble light across the scenery at an equivalent to between 150 and 450 Earthly Full Moons. A gray surface shown in a standard movie projection is a decent idea of what Plutonian sunlight would be like.

What chilly near vacuum passes for an atmosphere on Pluto is, in pre encounter figures, about 1 to 5 hundred thousandths of Earths in pressure, composed of Nitrogen, Carbon Monoxide and Methane. Pluto's overall color seemed similar to that of Neptune's Moon Triton which invited comparisons for many years.

The Path to Pluto

I had been at every Mars landing except Viking 2, and was at the Pioneer Jupiter and Saturn encounters as well as the Voyager Saturn, Uranus and Neptune flybys. It was especially at Jet Propulsion Laboratory (JPL), overseen by head of Public Affairs Frank Bristow where the landing and encounter press events cultivated a mixed crowd of invited guests which included actors, politicians, space authors and even artists. Some of these, like me, also obtained press credentials, but at times Frank was compassionate in letting in deserving people. The result was what can be called the beginning of the 'Gathering Of The Tribes', also called the 'Space Gypsies' by writer Mark Washburn in his 1983 book 'Distant Encounters: the exploration of Jupiter and Saturn' One could see and meet people whose book and articles you had read. One such story has a connection with this event.

As the Voyager 1 Saturn Encounter took place a group of space artists sat in a car making our way out of JPL. Suddenly Jon Lomberg made the awestruck announcement "There goes Clyde Tombaugh, the discoverer of Pluto!" And there he was walking by, the only American to discover a planet. His new book, with co author Patrick Moore, was being sold at JPL and I was one of those who bought it obtained both authors autographs. By the time of the later such events I made it to, often I would apparently be the only Space Artist there. But each time, for me it was a supreme place to be at that moment

. Here and there across the world there is a moment and place that becomes for whatever reason the most important, the most exciting, the 'coolest' place to be on the planet. This place darts about the globe like a moth bouncing across a lamp, sometimes predictable or repeating but most often not. I have been privileged to be at several such events. Some were Total Solar Eclipses, others were pivotal launches like that of the last Apollo Moon expedition and the first and the last Space Shuttle launches. Sometimes it has been at JPL and at NASA Ames as new worlds were revealed as never before. In the 1970s the outer planets one by one graduated from being tiny blobs seen in telescopes to distinct strange places, each a variation of how a world can turn out. The last really revelatory encounter such event had been the Voyager Neptune flyby in late August 1989. I was there with a borrowed video camera and had the time of my life. But 24 years is starting to be a long time ago and finally a new planet (writing in a traditional sense and ignoring the designation dispute) was finally making the transition to the realm of the known.

In the wake of the 1989 Voyager Neptune encounter a Pluto mission was advocated and fought through the thicket of bureaucracies and politics, with prominent crusaders including the Planetary Society and especially Alan Stern from the SouthWest Research Institute in San Antonio, Texas. After a protracted struggle, on January 19, 2006 The 'New Horizons' Pluto mission became the fastest spacecraft ever hurled from Earth, crossing the orbit of the Moon in only nine hours.

After launch Pluto underwent a reappraisal of its planetary status due to a controversially conducted 2006 vote of a small number of the members of the International Astronomical Union. Alan was among those who disputed this re classifying of Pluto from a planet to a dwarf planet. He defiantly raised a 'Pluto as planet' salute consisting of two hands held palms out with nine fingers extended for the nine planets. In the mean time Pluto, oblivious to what people wanted to call it, steadily moved in its lengthy orbit soon to be met by a work of Man.

Years of the journey of New Horizons would be spent in hibernation with periodic revivals. The awakening for the duration of the encounter commenced January 6, 2015. Later that month the LORRI (telephoto black and white camera) obtained images resolving the relative sizes of Pluto and Charon as they orbited each other, steadily surpassing what could be seen from Earth. The closest look at Pluto was reserved for a particularly contrasty portion of crude maps of Pluto made using the Hubble Space Telescope and ingenious light measuring methods. This was sensibly reasoned to be best for getting a look at a variety of surface types. The Pluto Encounter was structured around a 6 month interval with 12 weeks of intensive science May through July 2015. By June New Horizons was getting photographs of Pluto consistently better than Hubble's 20 year old images, and from then on we were in new observational territory.

 Just before my trip to APL I was working on a digital painting of the New Horizons spacecraft viewing the Pluto system at the moment of closest approach. Twice I updated the details of Pluto as they emerged in the improving photos in early July. On the 7th I was able to confidently show at least a fuzzy version of the face of Pluto the spacecraft would see then. Due to the speed of the spacecraft and the slowness of Pluto's 6.4 day rotation only one hemisphere would be seen in enough detail to examine the finer details and topography.On July 4 beepers sounded in people connected with the mission. New Horizons was out of contact with Earth for an hour and 20 minutes during which the spacecraft was in 'safe mode' which is an overriding set of instructions designed to 'do no harm' and restore contact with Earth if something goes wrong. This alarming event so close to Pluto arrival quickly had its cause zeroed in on and remedied in time to resume the encounter sequence July 7. But for a short while the mission had a scary air of suspense about it. As silent milestones were being reached and the targets growing noticeably in the camera frame every day, the people who wanted to be there prepared for their journeys all converging on the Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Maryland.


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