Prior to his Apollo 15 lunar mission, astronaut David Scott met Belgian painter and printmaker Paul Van Hoeydonck at a dinner party. It was there agreed that Van Hoeydonck would create a small statuette for Scott to place on the Moon, though their recollections of the details differ. Scott’s purpose was to commemorate those astronauts and cosmonauts who had lost their lives in the furtherance of space exploration, and he designed and separately made a plaque listing fourteen American and Soviet names. Van Hoeydonck was given a set of design specifications: the sculpture was to be lightweight but sturdy, capable of withstanding the temperature extremes of the Moon; it could not be identifiably male or female, nor of any identifiable ethnic group. According to Scott, it was agreed Van Hoeydonck’s name would not be made public, to avoid the commercial exploitation of the US government’s space program. Scott got permission from top NASA management prior to the mission to take the statue aboard his spacecraft, but did not disclose it publicly until a post-mission press conference.
Have you ever wondered what may be the purpose of the moon? Well, the moon is the shiny beacon that lights up the night as the sun lights up the day. This amber body is quite shy and doesn't always show itself, but when it does, the moon's brilliance overpowers the darkness. The surface of the moon inspires astronomers around the globe who religiously watch as our incandescent orb passes serenely through its natural cycle, but if you are an avid planet observer you will come to realise that the reflecting light from the moon through the telescope lens may interfere with your ability to clearly view even our closest planets. For this reason many planet watches believe the new moon cycle is the perfect time to catch a glimpse of another world. However, it was little Enceladus that gave astronomers their greatest shock. Even though the existence of Enceladus has been known since it was discovered by William Herschel in 1789, its enchantingly weird character was not fully appreciated until this century. Indeed, until the Voyagers flew past it, little was known about the moon. However, Enceladus has always been considered one of the more interesting members of Saturn's abundantly moonstruck family, for a number of very good reasons. First of all, it is amazingly bright. The quantity of sunlight that an object in our Solar System reflects back is termed its albedo, and this is calculated primarily by the color of the object's ground coating. The albedo of the dazzling Enceladus is almost a mirror-like 100%. Basically, this means that the surface of the little moon is richly covered with ice crystals--and that these crystals are regularly and frequently replenished. When the Voyagers flew over Enceladus in the 1980s, they found that the object was indeed abundantly coated with glittering ice. It was also being constantly, frequently repaved. Immense basins and valleys were filled with pristine white, fresh snow. Craters were cut in half--one side of the crater remaining a visible cavity pockmarking the moon's surface, and the other side completely buried in the bright, white snow. Remarkably, Enceladus circles Saturn within its so-called E ring, which is the widest of the planet's numerous rings. Just behind the moon is a readily-observed bulge within that ring, that astronomers determined was the result of the sparkling emission emanating from icy volcanoes (cryovolcanoes) that follow Enceladus wherever it wanders around its parent planet. The cryovolanoes studding Enceladus are responsible for the frequent repaving of its surface. In 2008, Cassini confirmed that the cryovolanic stream was composed of ordinary water, laced with carbon dioxide, potassium salts, carbon monoxide, and a plethora of other organic materials. Tidal squeezing, caused by Saturn and the nearby sister moons Dione and Tethys, keep the interior of Enceladus pleasantly warm, and its water in a liquid state--thus allowing the cryovolcanoes to keep spewing out their watery eruptions. The most enticing mystery, of course, is determining exactly how much water Enceladus holds. Is there merely a lake-sized body of water, or a sea, or a global ocean? The more water there is, the more it will circulate and churn--and the more Enceladus quivers and shakes, the more likely it is that it can brew up a bit of life. This gigantic "King of Planets" is considered by some astronomers to be a "failed star". It is about as large as a gas giant planet can be, and still be a planet. It is composed of approximately 90% hydrogen and 10% helium, with small amounts of water, methane, ammonia, and rocky grains mixed into the brew. If any more material were added on to this immense planet, gravity would hug it tightly--while its entire radius would barely increase. A baby star can grow to be much larger than Jupiter. However, a true star harbors its own sparkling internal source of heat--and Jupiter would have to grow at least 80 times more massive for its furnace to catch fire.