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Artist’s conception of Venus Express above Venus (ESA)
Tomorrow I will write the obligatory annual post about whom we lost in 2014. It’s always a solemn occasion which highlights the passing of many eminent figures (as well as the passing of yet another year) and raises troubling questions about what is truly important. But before we get to the human obituaries, I wanted to write a quick eulogy for an underappreciated figure lost to little fanfare at the end of 2014. Last month the robot explorer craft “Venus Express” was destroyed by falling into the volatile high-pressure atmosphere of our sister planet Venus (an operatic end which overshadows all but the greatest human deeds). The Venus Express was a satellite launched by the European Space Agency in November 2005. It reached polar orbit around Venus in April of 2006 and has been continuously sending back data since then until November 28th of 2014 when the last remaining fuel in the satellite was used to lift it into a high orbit. Scientists planned on monitoring the space probe during its long drift down to the top of the atmosphere, but something went wrong and the satellite was thrown into a spin (which made it unable to contact Earth). It is now presumed destroyed.
Venus Express was the first Venus mission undertaken by the ESA. Now that the craft is gone, the human race has no functional probes or spacecraft on or around Venus until the Japanese climate orbiter “AKATSUKI” is scheduled to reach there sometime in 2015 (although there have been some problems with that mission and the planned rendezvous may be postponed…or never happen).
This still from a NASA animation of a concept Venus mission shows a probe, one of many, beginning its descent into the Venus atmosphere.
Venus’ atmosphere is believed to have once been much like that of Earth. This is certainly not the case now! The data from Venus Express is now being analyzed in order to ascertain what happened to transform Venus into a hellish greenhouse (and strip it of its magnetosphere). Maybe we can also analyze this data with an eye on future sky colonies as well. Venus Express discovered hydroxyls in the atmosphere of Venus. It also discovered an ozone layer and a high cold atmospheric layer which is possibly dry ice. It undertook a series of aerobraking experiments which could prove very relevant to future craft inserted into Venus’ atmosphere. We need someone to analyze this data and plan those future missions! Speaking of which, why doesn’t NASA have more exploratory missions planned to this nearest planet? We should try to put a long-term floating probe into the upper atmosphere of Venus itself! That would be an amazing accomplishment and it would tell us more about whether floating sky colonies above Venus would even be possible. Nothing is more alluring than Venus! Let’s honor the Venus Express by learning from it and sending some more missions there pronto!
The Birth of Venus (Henry Courtney Selous, 1852, oil on canvas)
Humankind is always fixating on the Moon and Mars as the most likely spots for the first space colonies, but there is another crazy possibility. Aside from the Sun and the Moon, Venus is the brightest object in the night sky. Earth’s closest planetary neighbor, Venus is a veritable sister planet with extremely similar mass and volume. Because of its size and position in the solar system, a great deal of early science fiction concentrated around Venus. Dreamers and fabulists posited that beneath its ominously uniform cloud cover was a lush tropical rainforest filled with lizard people and pulchritudinous scantily clad women (the fact that the planet’s Greco-Roman name is synonymous with the goddess of love and beauty seems to have influenced many generations of male space enthusiasts).
Maybe we should head over there and check it out…
Alas, the space age quickly dispensed with mankind’s sweaty-palmed fantasies about life on Venus. In 1970 the Soviet space probe, Venera 7, was the first spacecraft to successfully land on another planet (after a long series of earlier space probes were melted or crushed by atmospheric pressure). In the 23 minute window before the probe’s instruments failed, the craft recorded hellish extremes of temperature and pressure. The temperature on Venus’ surface averages around 500 °C (932 °F), (higher than the melting point of lead) and the pressure on the ground is equal to the pressure beneath a kilometer of earth’s ocean. The planet’s surface is a gloomy desertlike shell of slabs interspersed with weird volcanic features not found elsewhere in the solar system (which have strange names like “farra”,” novae”, and “arachnoids”). Additionally the broiling surface is scarred by huge impact craters, and intersected by immense volcanic mountains (the tallest of which looms 2 kilometers above Everest). The tops of these mountains are covered with a metallic snow made of elemental tellurium or lead sulfide (probably).
A photo of the surface of Venus from Venera 13
The atmosphere of Venus is a hellish fug of carbon dioxide which traps the sun’s energy in a self replicating greenhouse gone wrong. Above the dense clouds of CO2, the upper atmosphere is dominated by sulfur dioxide and corrosive sulfuric acid. Once Venus may have had water oceans and more earth-like conditions, but rampant greenhouse heating caused a feedback loop which caused the planet to become superheated billions of years ago. Without an magnetosphere, solar winds stripped Venus of its molecular hydrogen (yikes!).
Artist’s Impression of the Surface of Venus
Thus Venus does not initially present a very appealing picture for colonization! Yet the planet’s mass is similar to Earth (and humans’ long term viability in low gravity is far from certain). The planet is closer than Mars and windows of opportunity for travel are more frequent. Fifty kilometers (30 miles) above the surface of Venus, the temperature is stable between 0 and 50 degrees Celsius (32 to 122 degrees Fahrenheit). Light crafts filled with oxygen and nitrogen would float above the dense carbon dioxide. Today’s visionaries and dreamers therefore have stopped thinking of tropical jungles and envision instead a world of Aerostats and floating cities. Although the rotation of Venus is too slow to craft a space elevator, the flying colonists of Venus probably could build some sort of skyhook with existing or near future technology. Such a hook could be used to lift raw materials from the surface to manufacturing facilities in the skies. As more aerostat habitats were built, the colony would gain manufacturing strength, safety, and a greater ability to alter the barren world below (increasingly overshadowed by flying cities and hovering countries).
Imagine then a world like that of the Jetsons where the surface was unseen and not thought about (except by scientists and industrialists). Floating forests and croplands could be assembled to mimic earth habitats and provide resources for a bourgeoning population of Venusian humans. Skyships would cruise between the flying city states dotted jewel-like in the glowing heavens. Over time these flying habitats could be used to alter the planetary temperature and shield the desolate lands below. Humankind and whatever friends and stowaways came with us would finally have a second home in easy shouting distance of Earth. How long would it be then before we took steps to take Earth life even farther into the universe?
Chullachaqui (painting by David Hewson)
If you are wondering through the great untouched rainforests of the Amazon basin, you will sometimes come across a clearing devoid of all vegetation save for a few trees. These bare patches are known as devil’s gardens and are said to be the haunt of the fearsome Chuyachaqui (or Chullachaqui), a shape shifting demon which delights in causing misfortune to travelers. Although the Chuyachaqui’s default form is that of a small misshapen man with one hoof and one human foot, the demon can change shape into a person known to the traveler in order to mislead the latter to doom.
Lemon ants (Myrmelachista schumanni), so named because they are said to have an acidic lemony taste
Scientists were curious about these small bare patches of forest. After carefully studying the ecosystem, they discovered that a force nearly as diabolical as the Chuyachaqui is responsible. The lemon ant, Myrmelachista schumanni, produces formic acid, a natural herbicide which it methodically injects into the plants in a “devil’s clearing”. The only plants which the ants leaves alone are Duroia hirsuta, “lemon ant trees” which have evolved a mutualistic relationship with the ants. The lemon ants keep the forest free of competing trees and plants, while the lemon ant tree is hollow inside—a perfect natural ant hive and its leaves provide a source of nutrition for the lemon ants (which are a sort of leaf-cutter).
A clearing filled with lemon ant trees
Large colonies of lemon ant trees have been found which are believed to be more than 800 years old—far older than the life of any ant colony or individual tree. It is remarkable to think these ant/tree settlements have been part of the rainforest since before the Mongol conquests.
Frequent visitors to this blog will know my longstanding fascination with the mammals of Australia. Because of its long geographic isolation, the island continent was mostly free of eutherian (placental) mammals until very recently–meaning that magnificent non-placental oddballs such as platypuses, wombats, echidnas, quolls, and numbats had plenty of time and space to survive and flourish. However there is one order of placental mammals which proved to be a big exception to this general narrative. Bats are eutherian mammals which can fly. They reached Australia in the Oligocene (the Oligocene era lagerstätten at Riversleigh have yielded 35 species of microchiropterans) and have been very successful ever since.
The Spectacled Flying Fox (Pteropus conspicillatus)
Australia has 65 known species of bats, most of which are still fast tiny insect eating microchiropterans. In recent times though a few species of large fruit-eating megabats have showed up and made inroads into the continent. One of these megabats is the subject of this post–the spectacled flying fox (Pteropus conspicillatus), a big handsome bat which is widespread along the coasts of New Guinea and seems to have established a beachhead in Northern Queensland.
A pregnant female Grey-Headed Flying-Fox (photo by Ofer Levy)
Spectacled flying foxes are gregarious social animals which live in huge colonies high in the canopies of the rainforest. At night they feed on nectar and pollen from tropical blossoms or they squeeze the juice from fruits like mangoes and figs. Although large for bats, the animals weigh less than a kilogram (2.2 pounds) and their wingspan is about 1.2 meters (4 feet). They are called spectacled bats because of the strips of yellow-tan fur around their eyes.
Spectacled Bat Close-up (Photo from CSIRO Sustainable Ecosystems)
It is unclear when the bats came to Australia but the fact that they are indigenous to many of the islands around New Guinea indicates that they are powerful fliers. Additionally, like certain other fruit bats, the spectacled flying fox can occasionally sip sea water without any ill effects.
An orphaned baby bat being cared for at Batreach in Kuranda
Even though they are hunted as bush meat in parts of New Guinea, Spectacled flying foxes are doing fairly well in that part of their range. Unfortunately in Australia they are having trouble with deforestation and with the paralysis tick (one of the many horrifying toxic pests which abound in Australia). Kindly and good-natured Australians frequently rescue orphaned bats, and, when not reintroduced into the wild the captive bats can live over 17 years in captivity. The bats are social animals, so the lonely orphans often bond deeply with their human rescuers.
Sam the orphaned spectacled bat
How can some people not like bats? (This image was taken at Tolga Bat Hospital by Steve Amesbury to promote the noble cause of bat conservation: see DontShootBats.com)
Don’t shoot bats! (or otherwise hurt them!)
ferrebeekeeper 