by Preston MacDougall
January 29, 2005
Perhaps they were referring to the far side of Luna (the name of our moon). Until 1959, when Luna 3, an unmanned Russian spacecraft, rounded the permanent lunar horizon, this half of the lunar surface had never been seen. Not by the glass eye of a telescope. Not by the dreamy eyes of young lovers. The same lunar hemisphere has been howled at since howling began.
Pointed away from the sun, the camera on Luna 3 was programmed to begin its shooting sequence when it detected the sunlight that was only being reflected off the far side of the moon at the time. The resulting 35 mm photographs had to be automatically developed on board the cylindrical spacecraft that was only about 130 centimeters long and 100 centimeters in diameter. Since FAX machines didn't exist, the image on the film was scanned in an analog fashion, again automatically, and the signal was finally transmitted back to Earth, where expectant engineers eagerly awaited. The grainy pictures showed the far side to be less cratered and more mountainous than the familiar face. Everything else was pretty much the same though. No cheese.
The far side of the moon experiences night and day like we do, but each lunar day lasts about one earthly month. Noon, on the farthest spot on the moon, occurs when we see a new moon. Well, we don't actually "see" it, since the last sliver of the crescent moon has completely waned.
Speaking of new moons, Titan, the largest of Saturn's many moons, has European astronomers going gaga over the pictures being sent back to Earth from Huygens, which are being cooperatively relayed by Cassini.
Both unmanned spacecraft, the Huygens probe softly parachuted onto Titan's surface after a 750 million-mile piggy-back ride on the Cassini orbiter. Controlled by NASA's Jet Propulsion Laboratory, in Pasadena, Cassini's main mission is to give us an up-close view of Saturn, the eternal Lord of the Rings.
Some of the more surprising discoveries surfacing from this mission involve the organic make-up of Titan's environment. The word "organic" is used here not in the garden variety sense, but in the chemical sense - comprising compounds of carbon and hydrogen primarily, but spiced-up with oxygen, nitrogen and occasionally a few other well-placed elements, such as sulfur and chlorine.
With temperatures around 300 below, on the Fahrenheit scale, there is evidence of methane rain, hydrocarbon boulders, and volcanic eruptions of coarse lava made of water and ammonia. For comparison, here on Earth, methane is also called "swamp gas", hydrocarbons are in your car's gas tank, and water/ammonia mixtures are sold as Windex. Just as photos of grandchildren no longer have to be developed, and manually delivered to grandparents, as they did in 1959, new photos of this moon can be radiated across the solar system, and downloaded onto your computer, digitally. Go to saturn.jpl.nasa.gov for the latest images and their scientific interpretations.
As a proponent of greenhouse-gasless nuclear energy, I would like to point out that Cassini's seven-plus years of space travel were powered by plutonium from the Savannah River Plant in South Carolina. Greenpeace leaders appealed to then-President Clinton to stop to the 1997 launch of Cassini. They cited the danger of a launch accident, or a mishap during its scheduled Earth fly-by in 1999, for a necessary gravity-assisted boost. Engineers have designed, and tested, these so-called Radioisotopic Thermoelectric Generators (better known by their PR-friendly acronym RTG's) to withstand hellacious fires, crashes and explosions, without releasing any fuel. While I can think of a recent "launch" that was not based on solid intelligence, Cassini's was.
Finally, and more positively, it is interesting to note that titanic Saturn-5 rockets put the first man on the moon in 1969, and now man-made plutonium-238 atoms have fueled a rocket to Saturn and its moon Titan. The circle is unbroken. I wonder where will it take us next.
Preston MacDougall is a chemistry professor at Middle Tennessee State University. His "Chemical Eye" commentaries are featured in the Arts and Public Affairs portion of the Nashville/Murfreesboro NPR station WMOT (www.wmot.org).