Researching the UFO Phenomena
Using Multidisciplines
Jerry Sievers Interview with Steven Hile
Segment 7
The Universe: A Revolution in Knowledge
Part 3 The Outer Solar System; the Asteroid Belt and Jupiter
Steven Hile: In Parts 1 and 2 we showed how Mercury, Venus and Mars in retrospect to the Earth have taught us much about planets and their formation including composition and the evolutionary energy affects of our core star the Sun. The inner system exists as a suite of rocky planets separate in composition from the gas giant planets of the outer solar system. The inner planets are separated from the outer planets by a belt of orbiting smaller bodies and debris know as the asteroid belt. The existence of this belt suggests a different formation composition and location isolation during formation of the system. The outer solar system is a suite of gas giant planets with multiple moons and small bodies. In Part 2 we spoke of the volatile elements which form the heavier molecules in a protoplanetary forming disk (hydrogen, oxygen, carbon, etc.). Protoplanetary disk research shows the majority of these elements are forced out of inner disks by the unsettled early stages of the central star. We should then expect to find the vast percentage of such molecules in the outer portions of extrasolar systems as well as our own Solar system.
Asteroid Belt
Located roughly between the orbits of the Mars and Jupiter the asteroid belt consists of numerous small irregularly shaped bodies and one minor planet orbiting in a series of defined belts. The asteroid belt region is termed the main belt to distinguish it from other concentrations of small objects and minor planets such as the Kuiper belt or the Scattered Disc. Long the notion that a planet once existed at this orbital distance from the Sun, the asteroid belt's mass in total is only approximately 4% of that of the Moon. The belt is currently believed to contain only 0.1% of its total original primordial solar disk mass. The belt has undergone considerable evolution since solar system formation, including ejections, internal heating, melting from impacts, radiation weathering, and micrometeorite bombardment. Computer simulations suggest that gravitational perturbations from Jupiter and Saturn to be the major reason for body ejection from the belt. Belt orbital resonance's and high orbital inclinations also have much to do with belt ejections.
The discovery of gaps in the distances of various asteroid body orbits from the Sun have proved to be periods of gravational fraction due to Jupiter's inward migrating orbital period which we look at later. In effect asteroids ended up in various belts separated into what are known as Kirkwood gaps. When a mean orbital period of an asteroid is an integer fraction of the orbital period of Jupiter at a certain point, a mean-motion resonance is created that is sufficient to perturb the asteroid into either a new orbit or off-orbit and out of the belt. In effect, asteroids are gradually nudged into different, random orbits with a larger or smaller semi-major axis. Asteroids also group together in the various belts such as the Flora family of asteroids. Jupiter has caused such kayos since it formed out of the solar nebula and is essentially the big bully in this area of the solar system. It also accounts for the hundreds of Earth orbit crossing asteroids and short period comets. There are also the interesting Trojan and Greek asteroids located at two of Jupiter's Lagrangian points which we will look at later.
When the main belt first formed, a natural "snow line" occurred where temperatures fell below the condensation point of water which for our solar system falls within the asteroid belt. Planetesimals forming beyond this snow line radius from the Sun accumulate ice. Those forming closer do not. In 2006 it was announced that a population of comets had been discovered within the asteroid belt beyond the snow line. Interestingly these main belt comets as they are known may be the major source for the Earth's oceans. The deuterium-hydrogen ratio of Earth's oceans is too low for the long term comets coming from beyond the outer edge of the solar system but are a closer matche the short term asteroid belt comets.
The existence of an ancient planet at this location stems from suggestions the asteroid belt fragments came from a planet that once occupied this orbital region. This hypothesis has however fallen from favor as science has shown such an occurrence it not possible. The belts location also fell in step with the Titius-Bode law for planet orbital distances which at the time seem to be supported by the solar system planet alignments except for Neptune. To date, there is no scientific explanation for the law and the consensus among astronomers is that it is a coincidence. Titus-Bode also has not been found to be true for exoplanet orbits as we will see later.
Note: In general, planetary formation is now strongly believed to occur by the long-standing nebular hypothesis: a cloud of interstellar dust and gas collapsed under the influence of gravity to form a rotating disk of material that then further condenses to form a central star and planets. During the first few million years of the Solar System's history, an accretion process of sticky collisions caused the clumping of small particles, gradually increasing in size. Once the clumps reached sufficient mass, they could draw in other bodies through gravitational attraction and become planetesimals. This gravitational accretion in the case of our solar system led to the formation of the rocky planets and the gas giants. As we will see later this process even continues presently for newly forming star disk systems now seen in the Milky Way galaxy. Why an asteroid gap exists has not been completely explained but may have much to do with Jupiter?
The asteroid belts largest object by far is the newly assigned and smallest dwarf planet Ceres. Recent observations show Ceres is spherical and about 590 miles in diameter. Ceres contains about a third of the mass of the asteroid belt and a Hubble Space Telescope study shows it to most likely have a rocky core and an ice mantle. Other named large objects are 4 Vesta, 2 Pallas, and 10 Hygiea all larger than 249 miles. Vesta appears dry and is located on the inner belt. Ceres and Vesta head a list of asteroids and minor planets which number in the thousands ranging in size down to dust particles.
Measurements of the rotation rates of large asteroids in the main belt show that there is an upper size limit. No asteroid with a diameter larger than 100 meters has a rotation faster than one rotation every 2.2 hours. For faster rotating asteroids the centrifugal force at the surface would be greater than the gravitational force. Any loose material on such a rotating body would be flung off, however solid body objects could rotate more rapidly. This suggests that the majority of asteroids with a diameter over 100 meters or more are actually rubble piles formed through accumulation of debris after collisions between asteroids.
Surprisingly chances of a spacecraft encountering a body while sailing through the asteroid belt are one-in-billion given the belt is actually sparsely populated. Belt objects are tracked and space craft if coming near one on the way to the outer solar system do perform science allowing instrument testing. The Galileo spacecraft visited 951 Gaspra an asteroid orbiting very close to the inner edge of the main asteroid belt. Gaspra was the first asteroid closely approached as Galileo flew by on its way to Jupiter on October 29, 1991.
The NASA Dawn robotic spacecraft launched September 27, 2007 entered the asteroid belt on November 13, 2009 after a 26 month trip. Dawn is scheduled to explore Vesta between 2011 and 2012, and Ceres in 2015. Dawn is the first spacecraft designed to enter the asteroid belt, orbit around a celestial body, study it, and then re-embark under powered flight to a second target. All previous multi-target missions involved rapid flybys. Dawn is propelled by three xenon ion thrusters firing one at a time. They have a specific impulse of 3,100 seconds and only produce a slight thrust. Very efficient the ion thrusters will drive Dawn to highest speed ever achieved for a spacecraft.
Since Vesta and Ceres are located nearly opposite each other in the asteroid belt Dawn will need to travel through half the asteroid belt's orbit to catch up to Ceres which will take from 2012 to 2015. Dawn will fly at a very similar speed to the material around it in the belt. The small meteoroids are far between and the chance of Dawn hitting one is small (but not totally negligible). Regions where higher than normal asteroid concentrations are thought to be will be avoided. Space is big but as plentiful as asteroids are, the distances between them is tremendous.
Jupiter
Orbiting the sun beyond the asteroid belt is the gas giant planet Jupiter. We have previously spoken to some of the havoc Jupiter has reigned on the solar system. We know quite a bit about Jupiter since it has been studied for a long period and a number of space craft have visited it. General information on Jupiter can be found in the links referenced. Here we address the specifics of this giant’s characteristics and effects on the solar system, and what it is teaching us about extraterrestial planets.
Jupiter contains over half of the solar system mass beyond the Sun. It is believed to consist of 75% hydrogen, 24% helium with the remaining 1% made up of all the other heavy elements on the periodic table. It’s this remaining 1% that gives Jupiter its bands and patterns since hydrogen and helium are plain gases and have only faint traces at the planets average temperature. The makeup of Jupiter reflects the composition of the early solar system accretion disk. Here are a couple of interesting comparisons; if Jupiters mass were 13 times greater, deuterium (heavy hydrogen) would burn in its core and it would be a type of brown dwarf star; if it had 60 times the mass it would be a hydrogen burning red dwarf star.
In the extrasolar planet search we are consistently finding planets larger than Jupiter orbiting other sun like stars. Larger can mean many different things. It could mean the planet has a greater diameter. It could also mean the planet has a greater mass. Models show you can't really get a planet that has a diameter greater than Jupiter's. Jupiter is about as big in terms of size as a planet can get. If mass were added to Jupiter it would actually shrink in diameter. Jupiter-like gas planets condense if more mass were added to them. The gravitational pull from added mass would compact the planet more effectively. Add more mass and gas planets get smaller and smaller until enough is add for hydrogen burning to occur and the upper layers are pushed out as with stars. Jupiter is at that "just-right" combination of mass and density that allows it to be as large as it is.
Gravitational forces on Jupiter force it to give off immense infrared energy. Models show that the pressures exist to form liquid metallic hydrogen in the interior. This forces a powerful magnetosphere and generates the strongest magnetic field in the solar system. Particles coming from volcanic activity on the inner moon Io as well as asteroid strikes on the other moons are accelerated by this magnetic field causing massive auroras giving off strong radio and x-ray energies. These particles enhance the magnetic field creating more charge particles that are accelerated giving off more relentless radiation which form into belts. The Jupiter system is the most dangerous place in the solar system in terms of radiation. Spacecraft which went through these belts were damaged by this radiation. There are astrophysical masars that are created by the magnetic fields at the planets poles. These are natural lasers accelerate particles that give off microwaves at the poles.
Jupiter is believed to have a rocky core of heavier elements but little is known about this. The outer atmosphere is visibly segregated into numerous bands at different latitudes with high turbulences and storms along interacting boundaries. A Great Red Spot or giant storm has been known to have existed since at least the 17th century when it was first observed by telescope. Jupiter shows a rapid rotation period of near ten hours which gives the planet a noticeable bulge around the equator. Its diameter of 88,846 miles is 11 times that of Earth and about one-tenth that of the Sun.
Jupiter radiates 60% more energy than it receives from the Sun. It’s believed some of this heat is residual left over from the collapse of the primordial nebula, but some may be from contraction. This internal heat source is presumably responsible for driving the complex weather patterns in the atmosphere unlike Earth where the Sun is the primary heat source.
Surrounding Jupiter is a faint planetary ring system made up of particles knocked off the inner moons. A small brighter inner ring aligns with two inner moons while a larger Gossammer ring centers on the moon Amalthea. Because the rings are made up of dust they are not visible from Earth but have a rich structure to them. Frictional effects of dust against dust tend to tell us that the ring orbits are transitory, that all of this material will eventually end up being consumed by Jupiter or ejected out of the system. But because the moons are constantly getting hit the rings are constantly getting replenished so they appear as permanent. One particular grain of dust is probably only a temporary particle in the rings. For the moons on a time scale it's going to take millions of years for this to happen.
Jupiter serves as a standard for extrasolar planet research. Many confirmed extrasolar planets are called hot Jupiters if they orbit close to their central star.We know our inner solar system would never have had the original mass to form a gas giant planet. Most of the mass here would either be pulled into the central star (the Sun contains 98% of the total mass of the solar system) or blown out of this inner part as described previously. Force to form in the outer parts of their protostellar accretion disks, hot Jupiter’s would be required to migrate inward to the positions where we are finding them. Planetary migration is the gravitational function of pulling on large bodies by all matter in the accretion disk. Hot Jupiter’s according to models have been pulled in toward the star they orbit passing through the star’s habitable zone until reaching an orbit which only takes days to go around the star. It is believed we have now found huge rocky planets very near their star which have had their huge gas atmospheres blown away. This is a finding we should be seeing more data on in the near future.
Jupiter is believed to have originally formed further out than it’s present orbital location and then migrated inward to its present orbit (type II migration). Why Jupiter stopped migrating inward would indicate the Sun’s inner protostellar accretion disk did not contain the matter needed. This would have had much to do with forming of the inner rocky planets including the Earth. Jupiter would have stopped accumulating major mass at this point leaving an asteroid belt and the inner rocky planets as they are. There is much ongoing research on this subject and the links given here provide further information.
A word here about the movie Avatar. We mentioned above that with the exoplanet search we are consistently finding planets larger than Jupiter orbiting other sun like stars. In other solar systems these gigantic planets many times the mass of Jupiter are orbiting well within the orbit of Mercury or very close to their central star. This was a finding that was never anticipated. A nice orderly suite of planets like our solar system was expected to be the common finding. This then would make for the good possibilities for life evolving on other earth like planets that were expected to exist in the temperate zones of Sun-like stars. This has presented segments of the scientific community and popular science in general with the need to search for ways around this major unexpected revelation. Avatar is an adaptation or projection of the potential of having a life bearing moon (called Pandora) orbiting around a gas giant planet which orbits in the stars temperate zone. Making it more interesting the gas giant planet orbits the star Alpha Centauri A, one the stars of the close by triple star system. The movie Avatar is now the most popular money making movie ever attend by record numbers even in China where it drew government attention. The movie should be known for what it is, science fiction and fantasy or nothing more than a Disney movie. However the politics exemplified in Avatar and the fallout from it leave a disturbing presence.
Our review of Jupiter here speaks to the many life-bearing dangers in a gas giant planet and any moons in orbit around it even if it were located in the temperate zone of a sun-like star. At present there are no links available speaking to the radiation and other dangers of such a planet system but there are links on the left bar addressing other subjects that make a planet like Pandora improbable.
For a couple of decades there has been a belief that Jupiter was needed to protect the Earth from the array of space rocks, comets and other potential Earth-orbit crossing objects. This thinking got a boost when the comet Shoemaker-Levy 9 event occurred. In orbital approach to Jupiter, Levy 9 first got shredded and then eaten by Jupiter. It was said "there's the proof, Jupiter protected us!" In recent modeling they asked the question what happens if there was no Jupiter and you have the same distribution of space objects to started with? What happens if Jupiter's a little bit smaller (say, replace Jupiter with Saturn at the same location)? They ran the situations to see how many objects might hit Earth. What they discovered was if Jupiter were removed, then some of the objects that normally end up entering Earth-crossing orbits stayed in the outer solar system. They were not a hazard at all. Place Jupiter back and it's gravitational pull grabs on to some of these failed objects, changes their orbits and puts them on trajectories toward the inner solar system. But then Jupiter usually catches them later and either flings them out of the solar system or eats them politely. What if instead of having Jupiter there a Saturn-sized planet were placed there? Saturn had enough gravity to take those objects and fling them into the inner solar system but not enough gravity to then fling them out of the solar system or eat them. Therefore if you replace Jupiter with Saturn really bad things would happen to the Earth. The bottom line seems to be while Jupiter protects us from some things, it also flings things at us.
Jupiter's Moons
Jupiter has at least 63 moons, including the four large moons called the Galilean moons (Io, Europa, Ganymede, and Callisto). The “solar system planets and moons” link on the left bar lists Jupiter’s current moons however more are being continually found. There have been a number of space craft fly bys of Jupiter. The pioneer missions in the early 1970's and then Voyager 1 and Voyager 2 in 1979. Then there was a gap until 1990s when Ulysses and Cassini both took fly by images. Then Galileo orbited the system for most of the 1990s. The majority of what we know about the details of the moons comes from the Galileo mission. The Pluto bound New Horizons mission passed by and was able to image one of the outer moons in the process. New Jupiter moons however have been mainly found by ground based instruments.
Above we addressed some of the effects of the strong Jupiter gravity affects on the objects in the solar system including Mercury. For Jupiter’s moons this strong gravity is a paradox. This field pulls in many objects and either ejects them on a new path or pulls them into orbit and will eventually eats them. For instance, Amalthea one of the four inner orbiting moons is on an orbit that it is going around Jupiter faster than it is rotating on axis. This causes tidal effects that eventually will cause Amalthea to drop into the atmosphere of Jupiter and be consumed. Any of the moons close enough to be orbiting faster than Jupiter's rotating are eventually going to be pulled in. But for the present they are just getting shredded into forming the gossamer rings.
Jupiter is constantly capturing bodies particularly small astroids and comets. Some of them depending on the way they were captured are orbiting Jupiter in the wrong direction. Many have highly inclined orbits and interact with one another. Some of them are going to end up flung back out of the system and some flung further into the system and consumed by Jupiter. Shoemaker-Levy 9 is an example of an object that could have become a moon had it's orbit been different.
The four Galilean moons are totally locked to Jupiter and almost synched with one another; Io is the closest moon in, then Europa, Ganymede and Callisto. The inner three are synced such that every time the third moon Ganymede goes around Jupiter once, the second moon Europa makes two orbits and Io makes four orbits. This has tweaked Io's orbit to be somewhat eccentric or oval shaped causing it to come closer to Jupiter. Io actually gets stretched in shape and its surface flexed a hundred meter. For a small moon to be flexed a hundred meters in size has forced a largely molten interior and resulted in the largest active volcanoes in the solar system; these are mega volcanoes! They spew material up and with Io’s weak gravity away from the surface where Jupiter pulls it away by the thousands of kilograms into the magnetic fields forming those violent plasma streams. The volcanoes on average are about forty kilometers across. The Galilean space probe at one point was going over a pole of Io when it got blasted with ash snow. Every time NASA sent Galileo passed Io they weren't sure if they were ever going to talk to it again.
Io’s surface is sulfur and silicates in shades orange, brown and various other shades due to the sulfurous compounds. Lava fields are everywhere with sulfur clouds and constantly refreshing lava from the volcanoes. The volcanic processes gave rise to a comparison of the visual appearance of Io's surface to a pizza. The materials produced by this volcanism provide material for Io's thin, patchy atmosphere and Jupiter's extensive magnetosphere.
The next moon out is Europa which gets a lot of attention because it is here that many scientists think some form of life might exist. It’s a perfect sphere, and has the least amount of up and down features. There are no mountains, valleys and only a few craters. Its top crust is basically ice believed to be five kilometer deep. Beneath is believed to be fifty kilometers of liquid ocean.
Because there are few craters geologists know the moon has been recently resurfaced but in this case with ice. There are cracks and swirls in the ice patterns which make it look like that which happens here on Earth when a lakes freeze, expand and crack. Scientists are trying to figure out what all the different swirling patterns, freckles and different strange features might be.
On Io there are volcanoes with molten rock pouring out. Europa, further away from Jupiter does not have molten rock. Instead the interior of the moon is warm enough to heat the water underneath, but it’s also exposed to space so there is an ice shell on top of at least five kilometers thick. With an ice shell there should be spots where cracks open and almost straight to the water. Features called freckles are believed to be warm water cells below the ice heated by interactions with Jupiter’s magnetic fields and gravitation. Warm cells of water are believe to rise to the surface and basically become hot water volcanoes that come up through the surface ice and make small mounds of ice. The ice shell may be tidally locked to Jupiter which would keep the same face of the moon toward Jupiter. Every time Europa goes around Jupiter it rotates once on its axis. There are theories that the core of the moon is rotating a little faster than the ice shell which with a salt ocean could generate magnetic fields. This could help heat the interior of the moon and keep the ocean vibrant under the surface ice.
Ganymede is a moon bigger than the planet Mercury. If it were in orbit around the Sun instead of Jupiter, it would be a full-fledged planet. It's the biggest moon in the solar system with a diameter is 3,268 miles, planet size. Ganymede has a rocky surface, some water ice but no atmosphere. It has a variation of light and dark surface areas and is highly cratered. It has a very complex geology, mountains, valleys and past volcanism. There are signs of lava flows but minimum erased craters. It’s also a moon that generates its own magnetic field. It’s believed to have a liquid iron core that is enough to give the moon its own magnetic field making it similar to Mercury in many ways.
Ganymede is not believed to have an icy shell and the impact craters show asteroid bombardment. It’s not known for sure if there is a subsurface layer of liquid water. The strange thing is the moon has some ice and there is some thinking that maybe there is an underground sea which helps to drive the magnetic field if it were salt water. As far as life is concern Ganymede is nowhere near as probable as Europa.
The fourth moon Callisto is another one of these rocky giant moons almost the size of Mercury. Heavily cratered and extremely old, the moon is covered in pox marks where it’s been hit by different debris and shows exposed ice beneath. In some places where it’s been hit there are ring patterns traveling out from impact craters. These wave patterns travel away from the craters like a splash in water. How these ring-like patterns formed is not known.
At more than twice Gamamedes distance from Jupiter Callisto is more isolated and does not participate in the mean-motion resonance in which the three inner Galilean moons are locked. Like most moons Callisto's rotation is locked to Jupiter with the length of its day about 16.7 Earth days.
Callisto isolation indicates it has never been appreciably tidally heated affecting its internal structure and the charged-particle flux from the Jupiter’s magnetosphere is relatively low (300 times lower than Europa’s). Unlike the other Galilean moons, charged-particle irradiation has a relatively minor effect on the Callistoan surface.
There is a lot of interest in NASA sending another mission to explore in particularly Europa and these moons one more time. Europa's unlit interior is considered the most likely location for extraterrestrial life within the Solar System. From the “natural perspective' life could exist in an environment similar to Earth's deep-ocean hydrothermal vents or the Antarctic Lake Vostok. To explore for the answers we want would be a huge challenge especially in subsurface oceans. There are research robots planned for under ice exploration whose technology could apply here. Because of the lack of light at this environment it would require the use of atomic energy sources whose current availability presents problems. While there is great interest in exploring any subsurface oceans, analysis of surface ice and other features on the Galilean moons is more likely in the short term.
Lagrange Points
This is a good point in our presentation of the solar system to discuss a natural occurrence which is controlled by the mass and related gravitational attraction of the planets, namly "Lagrange Points". We’ve discussed among other things the havoc Jupiter’s large gravitational pull reigns on the solar system but it's Lagrange Points are of particular interest. Each of the planets have their Lagrange points and the affects depended upon the planet mass and orbital location but those for the Earth and Jupiter have the most information available. There are five Lagrange Points in the solar system with each planet referenced to the Sun individually. They each have potential which for the Earth are exploited for space craft locations and for Jupiter and the other planets hold natural bodies and objects in essentially gravity free zones.
A planets gravity pulls on all the other bodies in space around it weakening with distance according to the inverse square law of physics. The concept is to take a two system body in space such as the Sun and the Earth. The gravity between these two bodies pull on each other with the gravitational pull from all the other bodies in the solar system present but negligible. If you take an object and place it at one of these five points, the Earth and the Sun gang up to keep it moving in lockstep with the Earth as it goes around the Sun. The same is true if you take the Earth-Moon the but on a smaller scale. These can be thought of as magical spots where the potential and kinetic energies of the two gravitational influence balance out just right. Any place outside of these points weird gravitational influences occur. Examples would be meteors that come into the Earth-Moon system. Depending upon their velocity and trajectory they are going to almost always skew in orbit and go on around the Sun, or in an extreemly rare situation threaten the Earth or Moon.
There are five Lagrange Points named L1 to L5:
Lagrange-1 is the point between the two masses that stays in sync with the smaller object. For the Earth this is the point in space nearer the Earth (1.5 million killometers) where the Earth-Sun gravity pull is equal. An object at Earth’s L1 point would orbit the sun in a 365+ day lockstep period with the Earth. The natural tendency would be for the object to move faster since it is closer to the Sun than Earth according to Kepler’s Laws. But because at the L1 point the Earth’s gravity is enough to counterbalance the Sun’s, it prevents a speedup of the object. Effectively it decreases the mass of the Sun to make the orbit speed slower and results in stable orbit around the Sun.
Objects at the first three Lagrange points need to be exactly positioned or they will not be stable. Spacecraft that are placed there must have their own engines to make constant corrections to stay at these points. Mathematically L1-L3 are called saddle-points. In certain directions the object quickly move out of Lagrange space. It’s described as trying to balance a marble on a horses back. L1 and L2 are convenient for objects that are not in the Earth orbit but follow the Earth around the Sun for communications purposes. With L1 between the Sun and the Earth its the perfect location for craft as the SOHO Solar obserbatory. Another advantage is an hour’s warning on solar storms coming our way giveing time to protect astronauts and put satellites into safety mode.
Lagrange-2 is the point beyond the Earth (930,000 miles) but in alignment with the Sun. Normally if you put an object on an orbital path bigger than the Earth's orbit, it will orbit at a slower volicity. If pull of the Earth is added it's like making the Sun a little more massive, so an object will orbit faster and still be stable at that greater distance. It's not entirely stable: just like L1, it's saddle shaped and objects can fall off the Lagrange point. It's still a good place to put spacecraft that have to make corrections because it makes communications easy. For instance, the Herschel satellite, the Planck satellite, the James Webb Space Telescope are all candidates for the Lagrange-2 point. WMAP, the microwave anisotropy probe that has given us all that data on the cosmic microwave background are at the Lagrange-2 point.
L2 is also a good place to protect objects a little from the Sunas well as the heat of the Earth. It's safer than having objects orbiting over our heads. The Sun’s radiation doesn’t get there and infrared and radio energies are a little quieter there.
Lagrange-3 is on the opposite side of the Sun from the Earth. Remember we are talking gravitational affects. At that location an object will be pulled on by both the Sun’s and the Earth’s gravity added together. This point is a little further from the Sun than the Earth is but it has the same orbital period staying in lockstep with the Earth. Similar to L2 in stability it again is a saddle point and objects are going to want to fall out of that spot if not balanced just right. There is no use of this point by spacecraft currently but it has potential for example a second SOHO craft but relay craft would be needed. There are plenty of possibilities if Lagrange Points of other planets are used and then there is the Earth-Moon points which can lead to crazy subjects.
The first three Lagrange points align with the Sun and planet. Points L4 and L5 lay in the planets orbit path and are the most stable. Point (L4) leads and (L5) lags behind at angles of 60 degrees. Point L4 pulled back by the planets gravity prevents objects from moving away while point L5 tugs objects forward. L4 and L5 have very large stable areas allowing objects to be gravitationally balanced between the Sun and planet. This is the opposite of the saddle type fall off of L1-L3. Objects located here require energy to be moved out. If an object moves into one of these points it will remain. They are like fairly flat top hills and once up on top there’s area to move around. Within these larger L4 and L5 points there is possible for little circular orbits with small objects orbiting around a larger object, even while the point goes around the Sun.
Currently there are no artificial satellites at Earth’s L4/L5 points and what is believed to be there are rocks, pebbles and dust. The density of objects here is probably higher than elsewhere in near Earth orbit.
Jupiter's L4/L5 points have known asteroids but the other gas giant planets have asteroids also. Jupiter’s asteroids at L4/L5 are known as the Trojans/Greeks and are distributed in two elongated, curved regions around the two points. If you were to look at a plot of where rocks are in the solar system, there are piles of them at Lagrange points for Jupiter, Saturn and Neptune. More details are found in given links.
Epilog
The information reviewed in this Part 3 is key to the solar system as we know it. From all available data the existence of the asteroid belt and Jupiter at its orbital location lends extensively to the existence of the inner solar system rocky planets including the Earth. There is little modeling on solar or star system formations. The Nice Model publish in 2005 is the current existing model and only address our solar system, apparently its intent. The Nice Model gives a general outline and establishes the migration definitions. It does not address the subject of hot Jupiter’s or the forming of other solar systems.
Based on the 400 some extra solar planets discovered to date our solar system does not contain enough mass to match the mass of many of the Hot Jupiter’s that have been discovered. These Hot Jupiter solar systems on average have apparently formed with much more mass than is in our system. There are some guesses what would have occurred if Jupiter had continued to migrate inward toward the Sun. Much of the mass of the inner solar system would most certainly be swooped up as the giant orbits inward. Some theory’s suggest that the other gas giants have a part in in Jupiter’s migration but the scattered matter in the early solar disk plays a part in both types of defined migrations.
What’s this have to do with UFO’s? The Hot Jupiter’s suggest the Universe holds some surprises and planets such as the Earth with complex life may not necessary be a norm. In any case the subject of Hot Jupiter’s and terrestrial planets will demand scrutiny in the future. A link to “The Rare Earth” provides an on-line publication which addresses many assumptions and political ideas which have formed around concepts and ideas that may not necessary have realities in the concepts of Naturalism or Ufology.
NEXT: Segment 7 Part 4: The Outer Solar System; Saturan, Uranus, Neptune and the Kiper Belt.
