Figure 6—Barnard Planetary System
Barnard
Barnard is a red dwarf star that is the second closest star to the solar system after the three-star Alpha Centauri system. Barnard was known only by the star catalog number of +4o 3561 until 1916, when the American astronomer Edward E. Barnard measured its proper motion and found it was moving at the high rate of 10.3 seconds of arc per year, or more than half the diameter of the Moon in a century. Parallax measurements soon revealed that the star was the second closest star system. Barnard's Star (or Barnard as it is called now) can be found in the southern skies of Earth, but it is so dim it requires a telescope to see it. The data concerning Barnard follows:
BARNARD DATA
Distance from Earth = 5.6x1016 m (5.9 lightyears)
Type = M5 Dwarf
Mass = 3.0x1029 kg (15% solar mass)
Radius = 8.4 x 107 m = 84 Mm (12% solar radius)
Density = 121 g/cc (86 times solar density)
Effective Temperature = 3330 K (58% solartemperature)
Luminosity = 0.05% solar (visual); 0.37% solar(thermal)
The illumination from Barnard is not only weak because of the small size of the star, but reddish because of the low temperature. The illumination from the star is not much different in intensity and color than that from a fireplace of glowing coals at midnight. Fortunately, the human eye adjusts to accommodate for both the intensity and color of the local illumination source, and unless there is artificial white-light illumination to provide contrast, most colors (except for dark blue—which looks black) look quite normal under the weak, red light from the star.
Note the high density of the star compared to our Sun. This is typical of a red dwarf star. Because of this high density, the star Barnard is actually slightly smaller in diameter than the gas giant planet Gargantua, even though the star is forty times more massive than the planet.
Rocheworld
The unique co-rotating dumbbell-shaped double planet Rocheworld consists of two planetoids that whirl about each other with a rotation period of six hours. As shown in Figure 7, the two planetoids or "lobes" of Rocheworld are so close together that they are almost touching, but their spin speed is high enough that they maintain a separation of about 80 kilometers. If each were not distorted by the other's gravity, the two planets would have been spheres about the size of our Moon. Because their gravitational tides act upon one another, the two bodies have been stretched out until they are elongated egg-shapes, roughly 3500 kilometers in the long dimension and 3000 kilometers in cross section.
Although the two planetoids do not touch each other, they do share a common atmosphere. The resulting figure-eight configuration is called a Roche-lobe pattern after E.A. Roche, a French mathematician of the later 1880s, who calculated the effects of gravity tides on stars, planets, and moons. The word "roche" also means "rock" in French, so the dry rocky lobe of the pair of planetoids has been given the name Roche, while the lobe nearly completely covered with water was named Eau, after the French word for "water." The pertinent astronomical information concerning Rocheworld follows:
ROCHEWORLD DATA
Type: Co-rotating double planet
Diameters: Eau Lobe: 2900x3410 km
Roche Lobe: 3000x3560 km
Separation: Centers of Mass: 4000 km
Inner Surfaces: 80 km (nominal)
Co-rotation Period = 6 h
Orbital Semimajor Axis = 18 Gm
Orbital Period = 962.4 h
= 160 rotations(exactly)
= 40.1 Earth days
Axial Tilt = 0o
One of the unexpected findings of the mission was the resonance between the Rocheworld "day," the Rocheworld "year," and the Gargantuan "year." The period of the Rocheworld day is just a little over 6 hours, or 1/4th of an Earth day, while the period of the Rocheworld "year" is a little over 40 Earth days, and the orbital period of Gargantua is a little over 120 days. Accurate measurements of the periods have shown that there are exactly 160 rotations of Rocheworld about its common center to one rotation of Rocheworld in its elliptical orbit around Barnard, while there are exactly 480 rotations of Rocheworld, or three orbits of Rocheworld around Barnard, to one orbit of Gargantua around Barnard.
Figure 7—Rocheworld
Orbits such as that of Rocheworld are usually not stable. The three-to-one resonance condition between the Rocheworld orbit and the Gargantuan orbit usually results in an oscillation in the orbit of the smaller body that builds up in amplitude until the smaller body is thrown into a different orbit or a collision occurs. Due to Rocheworld's close approach to Barnard, however, the tides from Barnard cause a significant amount of dissipation, which stabilizes the orbit. This also supplies a great deal of heating, which keeps Rocheworld warmer than it would normally be if the heating were due to radiation from the star alone. Early in the expedition, both Rocheworld and Gargantua were "tagged" with artificial satellites carrying accurate clocks, and the planets have been tracked nearly continuously since then. The data record collected extends for almost four years. The 480:160:1 resonance between the periods of Gargantua's orbit, Rocheworld's orbit, and Rocheworld's rotation, is now known to be exact to 15 places.
Rocheworld was explored extensively in landings made during Phase I and Phase II of the mission, and more detailed information about the double-planet, and its interesting astrodynamics, can be found in the Phase I and Phase II reports.
Gargantua
Gargantua is a huge gas giant like Jupiter, but four times more massive. Since the parent star, Barnard, has a mass of only fifteen percent of that of our Sun, this means that the planet Gargantua is one-fortieth the mass of its star. If Gargantua had been slightly more massive, it would have turned into a star itself, and the Barnard system would have been a binary star system. Gargantua seems to have swept up into itself most of the original stellar nebula that was not used in making the star, for there are no other large planets in the system. The pertinent astronomical information about Gargantua follows:
GARGANTUA DATA
Mass = 7.6x1027 kg (4 times Jupiter mass)
Radius = 9.8x107 m = 98 Mm
Density = 1.92 g/cc
Orbital Radius = 3.8x1010 m = 38 Gm
Orbital Period = 120.4 Earth days (3 times Rocheworld period)
Rotation Period = 162 h
Axial Tilt = 8o
The radius of Gargantua's orbit is less than that of Mercury. This closeness to Barnard helps compensates for the low luminosity of the star, leading to moderate temperatures on Gargantua and its moons.
Gargantuan Moon System
There are nine major moons in the Gargantuan moon system. Their orbital and physical properties are listed in the following table. The five smaller moons are rocky, airless bodies, while the four larger moons have atmospheres and show distinctive colorings. All the moons are tidally locked to their primary.
Figure 8 presents a comparison of the orbits of the four large moons in the Gargantuan system with the orbits of the four large moons in the Jovian system. The Gargantuan system is seen to be quite similar to the Jovian system, although a little more compact.
Jupiter Io Europa Ganymede Callisto
71 420 670 1070 1880 Mm
( )—————o———o———o———————o—
( )———o——o———o———————o————
98 330 530 730 1650 Mm
Gargantua Zulu Zuni Zouave Zapotec
Figure 8—Comparison of Gargantuan and
Jovian Moon Systems
Conjunctions
The three inner large moons, Zouave, Zuni, and Zulu, can exert significant tidal effects on each other. This happens during a conjunction, when the distance between the two moons is a minimum. After a conjunction has once occurred, it will reoccur when after a certain time period, the inner moon (which always revolves faster than the outer moon) has rotated exactly one revolution more than the outer moon. The joint conjunction periods for the thre
e innermost large moons of Gargantua are:
Zulu/Zouave21.1 h
Zulu/Zuni28.9 h
Zuni/Zouave78.4 h
Triple conjunctions, when all three moons are nearly in alignment, are much rarer. The triple conjunction period is about 549 hours (about 23 Earth days). This triple conjunction occurs every 26 conjunctions of Zulu with Zuni, 19 conjunctions of Zulu with Zouave, and 7 conjunctions of Zuni with Zouave.
Quadruple conjunctions, when all three moons and Barnard are nearly in alignment, are even rarer, occurring every third triple conjunction. The quadruple conjunction period is about 1646.8 hours. This is about 68 Earth days, 55.5 Zuni days, 111.5 Zulu days and 33.5 Zouave days.
Intermoon Tides
Since the tidal force exerted by one moon on another goes as the inverse cube of the separation distance, the tides will be short and strong during conjunction, but negligible otherwise. This is a different situation than the tides on Earth, where the distance from the Earth to the Moon and the Sun stays nearly constant with time. Because the distance from the Earth to the tide-making body stays roughly constant, the dual oceanic tidal bulges (one bulge toward the body making the tide and a matching bulge in the opposite direction) from the tidal effects of the Moon and Sun stay roughly constant in height. The lunar tide turns out to be roughly twice the height of the solar tide because the closer proximity of the Moon more than makes up for its smaller mass. The approximately twice daily variations in tides that are observed on the Earth comes from the Earth rotating its continents around underneath the two oceanic bulges one each day. The seasonal variations of spring tides and neap tides occurs because the Sun and Moon tidal bulges move with respect to each other from new moon to full moon, and season to season, sometimes reinforcing each other and sometimes partially canceling each other.
On Zuni, there are calm seas most of the time with a single modest periodic tide from Barnard that is 1.5 times the height of a high tide on Earth (about 1.5 meters). This Barnard tide comes every 15.1 hours or twice each Zuni day of 30.2 hours. On top of this periodic tide from Barnard there are superimposed sharp impulse tides caused by the close passage of Zuni by the nearby moons Zulu and Zouave. There is a conjunction with Zulu every 28.9 hours or slightly less than once a day. The Zulu tide is 4.5 meters or 4.5 times the height of an Earth high tide but the surge only lasts 3.4 hours. For the remaining 25.5 hours until its next passage, the tidal effects of Zulu on Zuni are negligible. There is also a conjunction with equally nearby Zouave every 78.4 hours, or 2.6 Zuni days. The Zouave tide is 6.5 meters or 6.5 times the height of an Earth high tide. The surge lasts for 6.2 hours out of the 78.4 hour interval between surges. When there is a triple conjunction, with Zulu and Zouave both passing by Zuni at the same time, the tides can become very large, with tides greater than ten times an Earth high tide. The maximum tidal effect experienced during a triple conjunction varies, since the alignment of the three moons is more precise during some triple conjunctions than others. Then, when Barnard is also lined up with the three moons, its periodic tide adds to the impulse tides of the two moons. The triple conjunction tides reach a maximum every 20,078 hours (about 2.3 years) of 12.4 times an Earth high tide. This produces a tidal surge with a height of nearly 13 meters (40 feet).
Illumination
The major source of illumination on Zuni is from the star Barnard. Barnard, however, not only has a weak luminosity of 0.05% that of the Sun, but it has an angular diameter of only 0.25 degrees in the skies of Zuni, which is half the diameter of the Sun in the skies of Earth. Gargantua is so large and so close to Zuni that it covers 21 degrees in the sky over Zuni. As a result, a substantial amount of illumination comes from the planet in addition to the light from Barnard. On Zuni, at "full moon," when Barnard is over the outer pole, the light from Gargantua is 1.5 percent of the light from Barnard. For comparison, the light flux from the Earth's Moon is only one-millionth that of the Sun, because the Moon has a low albedo and covers only a half-degree in the sky, while Gargantua has a high albedo and covers 21 degrees in the sky.
The illumination from Gargantua is most noticeable at a site on the inner pole of Zuni, where there is nearly always light, either from Barnard or from Gargantua. A site on the outer pole of Zuni, however, never seeing Gargantua anyway, is only illuminated by the light from Barnard, and so therefore has a normal day-night cycle (although 30.2 hours long instead of 24 hours long).
There is also illumination from the other large moons around Gargantua. From Zuni, at an orbital distance from Gargantua of 530 Mm, the inner moon Zulu, with an orbital distance of 330 Mm, looms to 1.5 degrees in size as it passes over the disk of Gargantua (three times as large as our Moon in the Earth sky) at the time of conjunction and high tide and is still 0.35 degrees in diameter at opposition, just before it goes behind Gargantua. The next moon out, Zouave, at 730 Mm from Gargantua, varies from 1.66 to 0.26 degrees in angular diameter between conjunction and opposition, while Zapotec, at 1650 Mm from Gargantua, varies from 0.17 to 0.26 degrees.
Shadowing
Zuni experiences an eclipse of Barnard by Gargantua once every rotation. The eclipses are most noticeable for a site on the "Inner" side of the moon. Since Zuni is tidally locked to the planet, this is the side that always faces Gargantua. At the Inner site, the eclipse occurs at high noon and cuts 1.8 hours out of the 15.1 hour Zuni daylight period. If the site is on the "Leading" side of the moon, the side that always faces the direction of the motion along the orbit and where water vapor from Zulu and carbohydrates from Zouave fall out of the sky, then Gargantua hangs perpetually on the sunrise side of the horizon, cut in half by the horizon. Barnard rises from behind Gargantua, causing a late sunrise. For a site on the "Trailing" side, there is an early sunset as Barnard sets behind Gargantua hanging perpetually halfway down the sunset horizon. For sites on the "Outer" side of the moon, always facing away from Gargantua, the eclipse occurs at local midnight, off on the other side of Zulu, so nothing really noticeable is observed.
SECTION 3
BIOLOGY
Prepared by:
Katrina Kauffmann—Biology
Deirdre O'Connor—Zoology and Botany
With Contributions By Zuni Explorers:
Cinnamon Byrd—Zoology
John Kennedy—Physiology
Nels Larson—Botany and Genetics
Reiki LeRoux—Anthropology
Little White Whistler—Oceanic Lifeforms
Introduction
Alien lifeforms were found in both the land and ocean regions of Zuni, the fourth moon of Gargantua. In addition, three members of the exploration team were intelligent alien lifeforms from the double-planet Rocheworld, called flouwen. The biology of the Rocheworld flouwen will be summarized first, followed by a discussion of the Zuni lifeforms.
Flouwen
The dominant species on the Eau lobe of Rocheworld have been given the common name of "flouwen" (singular "flouwen," taken from the Old High German root word for flow). The flouwen are formless, eyeless, flowing blobs of brightly colored jelly massing many tons. They normally stay in a cloudlike shape, moving with and through the water. When they are in their mobile, cloudlike form, the clouds in the water range from ten to thirty meters in diameter and many meters thick. At times, the flouwen will extrude water from their bodies and concentrate the material in their cloud into a dense rock formation a few meters in diameter. They seem to do this when they are thinking, and it is supposed that the denser form allows for faster and more concentrated cogitation.
The flouwen are very intelligent—but non-technological—like the dolphins and whales on Earth. They have a highly developed system of philosophy, and extremely advanced abstract mathematical capability. There is no question that they are centuries ahead of us in mathematics, and further communication with them could lead to great strides in human capabilities in this area.
The flouwen use chemical senses for short-range information gathering, and sound ranging, or sonar, for long range information g
athering. Since sonar penetrates to the interior of an object, especially living objects such as flouwen and their prey, sonar provides "three-dimensional sight" to the flouwen and is their preferred method of "seeing." The bodies of the flouwen are sensitive to light, but, lacking eyes, they normally cannot look at things using light like humans do. In general, sight is a secondary sense, about as important to them as taste is to humans. One of the flouwen learned, however, to deliberately form an imaging lens out of the gel-like material in its body. It used this lens as an "eye" in order to study the stars and planets in their stellar system. Called White Whistler by the humans, this individual was one of the more technologically knowledgeable of the flouwen. White Whistler has since taught the eye-making technique to the rest of the flouwen.
In genetic makeup, complexity level, and internal organization, the flouwen have a number of similarities to slime-mold amoebas here on Earth, as well as analogies to a colony of ants. The flouwen bodies are made up of tiny, nearly featureless, dumbbell-shaped units, something like large cells. Each is the size and shape of the body of the tiny red ants found on Earth. The units are arranged in loosely interlocking layers, with four bulbous ends around each necked-down waist portion, two going in one direction and two going in the other, so that the body of the flouwen is a three-dimensionally interlocked whole.
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