Aurelia and Blue Moon
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Aurelia and Blue Moon are hypothetical examples of a planet and a moon on which extraterrestrial life could evolve. They are the outcome of a collaboration between television company Blue Wave Productions Ltd. and a group of American and British scientists who were collectively commissioned by National Geographic. The team used a combination of accretion theory, climatology and xenobiology to imagine the most likely locations for extraterrestrial life and most probable evolutionary path such life would take.
The beginning concepts appeared in a two-part television broadcast called Alien Worlds, aired in the UK by Channel 4. Channel 4 has also released a DVD of the programme. The show was also aired on the National Geographic Channel as Extraterrestrial.
The first program in the series focused on Aurelia, a hypothetical Earth-sized extrasolar planet orbiting a red dwarf star in our local area of the milky way. This fictional world might resemble the recently discovered real exoplanet Gliese 581 c. The second focuses on a moon called Blue Moon, which orbits an enormous gas giant that is itself orbiting a binary star system. The show blurred the lines between science fiction and science fact.
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[edit] Reasons for theorizing
Discoveries regarding extra solar planets were first published in 1989 raising the prospect of whether life (as we know it or imagine it) could be supported on other planets. It is currently believed that for this to happen a planet must orbit in a relatively narrow band around its parent star, where temperatures are suitable for water to exist as a liquid. This region is called the habitable zone.
The smallest non-pulsar planet yet found (as of April 2007), Gliese 581 c, has a mass larger than Earth's and orbits the red dwarf star Gliese 581. All currently known smaller extra solar bodies orbit pulsar PSR 1257+12.
The sensitivity of current detection methods makes it difficult for scientists to search for terrestrial planets smaller than this. To allow smaller bodies to be detected, NASA is studying a project called the Terrestrial Planet Finder (TPF), a two-telescope concept slated to begin launching around 2014. However, Congressional spending limits under House Resolution 20 passed on January 31, 2007 by the U.S. House of Representatives and February 14 by the U.S. Senate have all but canceled the program.
Prior to the TPF's cancellation, astrophysicists had begun speculating about the best places to point the telescope in order to find Earth-like planets. While life on earth has formed around a stable yellow dwarf, solar twins are not as common in the galaxy as red dwarf stars, which have a mass of less than one-half that of the Sun and consequently emit less heat, or bigger, brighter Blue giants. In addition, it is estimated that more than a quarter of all stars are at least binary systems, with as many as 10% of these systems containing more than two stars (trinary etc.) - unlike our own sun, which has no companion. Therefore it may be prudent to consider how life might evolve in such environments. Such speculation may still be of use should a future planet-finding telescope be launched.
[edit] Aurelia
The scientists on the project theorized that aiming the TPF at a red dwarf star might yield the best opportunities for seeing smaller planets. Due to the slow rate at which they burn hydrogen, red dwarfs have an enormous estimated lifespan; allowing plenty of time for life to evolve on surrounding planets.
[edit] Tidal lock
However, the dwarf's smaller nature and feeble heat/light output would mean that such a planet would need to be particularly close to the star's surface. The cost of such an orbit would be that an Earth-sized body would become tidally locked. When this happens, the object presents the same face to its parent at all times as it orbits, just as the Moon does with the Earth (more technically, one sidereal day is exactly equal to one year for the orbiting body).
[edit] Traditional theories
Traditional scientific theories proposed that such a tidally locked planet might be incapable of holding on to an atmosphere. Having such a slow rotation would weaken the magnetic effect that protects the atmosphere from being blown away by solar wind (see Rare Earth hypothesis).
[edit] Traditional assumptions tested
Nonetheless, the scientists employed by the programme decided to test the traditional assumptions for such a planet and start a model out for it from a proplyd through to its eventual death. Their estimations suggested such a planet could indeed hold on to its atmosphere, although with freakishly unusual results by Earth standards. Half of Aurelia would be in perpetual darkness and would be in a permanent ice age. The other half would contain a giant, unending hurricane with permanent torrential rain at the point directly opposite the local star. In between these two zones would be a place suitable for life.
[edit] Continued theories
The theorizations continued, and assuming that there was land in this habitable zone, it would be likely to form large networks of river deltas and swampland, due to rain runoff from the nearby storm.
At the far end of assumptions about Aurelia were attempts to construct lifeforms based on Earthly evolutionary models and how ecosystems might develop. The scientists assumptions included the idea that the long life of a red dwarf allows for evolution to fine tune any ecosystem on the planet. The scientists involved in the project hypothesized that the vast majority, if not all, of extra-solar biology will be carbon based.
This assumption is often referred to by critics as carbon chauvinism, as it may be possible for life to form that is not based on carbon. However, carbon is more flexible than other elements, allowing life it is made of to evolve at a much faster rate. Since all environments are likely to undergo massive change, this is vital.
From this carbon-based hypothesis the scientific team assumed some form of staple photosynthesizing animal/plant combination would be the principle autotroph. They decided upon a plant-like creature called a Stinger Fan. It has five hearts and limited mobility. Its fan-like leaves trap the red dwarf star's energy to produce sugars. Its hearts pump them around its body.[1]
Feeding upon the Stinger Fans are six-legged semi-amphibious creatures called Mudpods, somewhat like a cross between a beaver and a large newt with the eyes of a snail. Upon that animal, a large emu-like carnivore, a Gulphog, is the main predator. Finally, with no apparent explanation from within the Alien Worlds program, there is a second semi-amphibious creature called the Hysteria which was a cross between a plague of tadpoles and piranha. These tiny creatures can form one huge super organism and move together up banks to paralyze and consume other animals.
The planet's ecosystem suffers from a number of particular peculiarities, most notably evolutionary quirks to allow all living organisms to detect and avoid solar flares. Red dwarf stars are unstable and eject frequent solar flares. Such intense ultraviolet radiation is deadly to all carbon-based life forms as it breaks down the atomic bonds formed by organic compounds. The flare stage may only be when they are relatively young. See, Habitability of red dwarf systems
[edit] Blue Moon
Blue Moon is covered in life-giving water and an atmosphere so dense that enormous creatures can take flight. The Blue Moon orbits a Water Cloud Jovian planet (a Jupiter-like planet that is cool enough to have visible rain clouds in its atmosphere) orbiting a close binary star system. The Blue Moon itself is roughly an earth mass but has an air pressure around three times that of Earth's at sea level.
A distinguishing feature of Blue Moon is that it has no polar ice caps: the thick atmosphere keeps temperatures constant across the moon's surface. There is also a greenish haze over the moon from floating moss and algae, the Skywhale's main food supply.
The denser atmosphere allows more massive creatures to remain airborne than on Earth. Skywhales, gargantuan whale-like animals which evolved away from the ocean into the air, fill the ecological niche this creates. Because of the increased muscle power from excess atmospheric oxygen, these creatures can have wingspans of ten metres and remain airborne their entire lives.
Humans could not live on the Blue Moon: the high levels of oxygen push the atmosphere to the brink of spontaneous combustion during lightning storms. Carbon dioxide levels are thirty times higher than on Earth making the air clammy and warm. Like our moon, Blue Moon is "tidally locked," meaning it keeps the same side of the moon faced towards its planet.
With an orbital time of roughly sixteen days, that means eight days of continuous night and eight days of continuous daytime. The long days and nights also create strong cross-hemisphere winds that help keep the Skywhales afloat, in addition to the density of the atmosphere.
The Skywhales are prey to the insectoid Caped Stalkers, colony-living predators that have several different tasks. Scouts find Skywhales and mark them with a special scent, then return to the nest to spread the word. Workers then swarm out in huge numbers, detecting the whale and working together to bring it down from the sky and kill it. Finally, there is a Queen, who stays in the nest and constantly lays eggs that become new Stalkers. The Stalkers are also prey, for the Pagoda branches are draped with the lethal webs of the plant-like Ghost traps. Once a Stalker is helplessly caught in a Ghost trap web, the carnivore uses its tentacles to lift its catch up into its mouth, to be digested in a primitive stomach of acid.
As well as Skywhales, giant Kites also fly above the forest canopy. These parasole-like grazers can grow up to five metres in diameter and still stay airborne. Their 'tethers' help control their floating, while their jellyfish-like tentacles snatch Helibug larvae from the water-filled skyponds. Helibugs have a trilaterally symmetrical body plan, with three eyes, three wings, three legs, three mouth parts and three tongues.
The entire Blue Moon land mass is coated in two main plant types, the Pagoda Trees and the Balloon Plants. Pagoda Trees interconnect with each other to allow them to grow 700 feet high. Their hollow leaves collect rainwater, since the trees are too tall to draw it from the ground. Balloon Plants release their seeds by filling them with hydrogen to float in the dense atmosphere, in a similar way to kelp on Earth.
[edit] See also
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[edit] References
- ^ Alien Worlds: Stinger Fan. Retrieved on 2007-04-29.
