Moving the solar system
A search and discovery story for the year 2048

by Oliver Knill, November 1997


Large prominence, reduced from Nasa animation April 2000 The essay is based on Zwicky's monstrous idea to do space travel by moving the entire solar system. In the fictuous discovery story, it is reported how scientists learn in 2048 to control some parameters in the nuclear fission of the sun by triggering asymetric burning in the sun. This allows them to produce a tiny acceleration of the sun. This is used to change the dynamics of the solar system and prevent a disastrous collision with an asteroid.

asteroid flyby, reduced from Nasa pictures April 2000 This document was submitted in November 26, 1997 to the essay contest "Physics Tomorrow" which was hold by the journal 'Physics Today'. The task of the contest was to write an essay as it could appear in 50 years in Physics Today. While writing this essay, I was not aware that two movies on Asteroid impacts were in the making ("Armagedon" and "Deep impact"). Later in 1998, there was even a false alarm on an asteroid on collision course.
The footnotes after each paragraph and the real web links to the previously fictive scientific references to the essay were added when preparing this document for the web. (January 2000, the 2 Nasa animations were added in April 2000). A discovery of an object ( on Nov 2. 2000, CNN ) or an object, one did not even see before it had passed on March 8, 2002). An other close encounter occurred on 14. June 2002 when an asteroid of the size of a football pitch passed within 75'000 miles. It was discovered only 3 days later. In February 2013, after the close flyby of Asteroid 2012 DA14 and an impact of a smaller one on the same day in Russia, the interest has grown even more. A view of near earth asteroids. Many articles in the press like Slate, NBCNews, Space.com, Guardian.
Added in February 2007: A Spiegel online article (german) mentions asteroid Apophis 2004 MN4 which has a chance of hitting the earth in 2036. Added in March 2007: A Harald article on NASA plans. Added in November, 2011: 2005YU55 flyby Nov 8-9, 2011. Added, Jan, 26, 2012: An article in the Spiegel. Added, mar, 3, 2012: 2011 AG5 on the radar. Presentation[PDF]
Über Fritz Zwicky
On Fritz Zwicky


Added in January, 2012: The Swiss TV


1. Discovery of a collision orbit


Inner asteriods The Earth orbits the Sun in a sort of cosmic shooting gallery. It is subject to impacts from comets and asteroids. While the primary source of these objects is the main asteroid belt, there are minor planets until wide outside the Kuiper belt, where detection and observation is difficult. While the knowledge of the inner and outer neighborhood of the solar system has grown [4] so does our awareness of danger. Eight years ago, routine computations have shown that one of the minor planets which shoots through the solar system in an abnormal eccentric orbit has a chance of hitting the Earth in the year 2098. Since then, Earth and space based radar and optical telescopes have determined accurately the location, the speed and the shape of this asteroid. Simulations on the worldwide network of supercomputers (WWNS) found a positive Lyapunov exponent for the orbit, a sign for chaos. The scientists became alarmed, when Monte Carlo simulations predicted a substantial chance of an impact with Earth on the northern hemisphere. The reason for the uncertainty is in that the impact angle is in the critical range, where also reflection is possible.
Footnote: The information in this section was taken from impact.arc.nasa.gov . There is some uncertainty about the likelyhood of an impact. But the danger is there and monitoring is done. The Newtonian n-body problem allows the possibility of chaotic orbits. Such orbits would indeed be hard to predict. The Lyapunov exponent of a celestial object moving in the gravitational field of the planets is small because of the slow angular motion of the planets. Obtaining an object with a highly unpredictable orbit is unlikely but not impossible. Image source: impact.arc.nasa.gov.


Crash predictions


Cretaceous impact Long time predictions of a catastrophic asteroid impact are difficult. If the object is large enough, the Earth's climate can be perturbed on a global scale because large quantities of dust gets injected into the stratosphere. In case of an impact from a meteor with 20 km diameter already most of population is expected to perish. The bad news are that the object targeting Earth has a diameter of 90 kilometers. A full impact would probably mean an immediate extinction of any life because a temporary atmosphere of rock vapor develops at temperatures of one thousand degrees Celsius on Earth. In comparison, the meteor producing the Cretaceous impact 65 Million years had a 10-20 km diameter. There are geological indications that impacts of the size of 100km might have occurred in the early history of our planet. Each could have destroyed previously existing life.
Footnote: This section was compiled from an article on crash predictions of asteroids and summarizes what is currently believed to happen. Image source: impact.arc.nasa.gov


Search for a defense plan


Imact picture A research program of the world science foundation (WSF) brought together scientists from different disciplines with the aim to search for a solution. Preventive measures for large asteroid impacts were never followed because the risk for accidents or misuse of such a shield was considered too high in comparison with the impact probability. The political situation hardly allows now to revive a nuclear weapon program since the tragic 2020 missile accident which has led to a subsequent complete ban of any nuclear weapons. It will therefore be impossible to send and detonate huge hydrogen bombs near the asteroid and blow it into pieces.
Footnote: the risk of a nuclear accident by an erroreous launch of a missel is a fact. Huge nuclear arsenals still exist. It is also reasonable to expect that an accident would lead to more awareness and maybe even to a ban of nuclear weapons. A world science foundation does unfortunately not yet exist. Image source: impact.arc.nasa.gov .


A research conference


Gaspra The most recent conference on the impact issue was organized this spring by the former NASA Ames Space Science Division. It was supported by most main universities and international laboratories. Scientists who are not directly involved were invited to attend the conference via Internet. Research scientists were encouraged to send ideas in any of the involved areas. The proposals are constantly updated and evaluated. As a result, a large tree of ideas has grown. While all material is accessible online, the authors of the submissions were kept anonymous. This allowed unbiased evaluation as in journal publications, where it now became standard to keep authors of papers anonymous during the refereeing process.
Footnote: Anonymous submissions of articles to journals would eliminate biased referee work. The later is sometimes done rather purely, sometimes by diletantism, more often by lack of time. On the other hand, all the referee reports and names of the involved referees (also of eventual earlier rejections) should be added to the published articles. This would give some credit to this important part of scientific work. Image source: NASA .


Space travel


Alpha Centauri One of the ideas which emerged from that big "think tank" scored badly first on the evaluation scale. Indeed, the idea looks crazy at a first glance. It is a suggestion of the astronomer Fritz Zwicky (1898-1974) in the late sixties of the last century to make space travel by moving the solar system. Zwicky was an eccentric Caltech astronomy professor who was proud of having achieved in 1957 the first shot of a pellet of aluminum into interplanetary space. Zwicky thought that one could use the whole solar system as a "space ship" in order to travel to other stars. He speculated that this should be accomplished by shooting high velocity particles onto the Sun and bring them there to fusion. He stated in his book [5] that it should be possible to travel like this to the star system Alpha-Centauri during a 2500 year trip.
Footnote: A website on Alpha Centauri . Zwicky indeed proposed this idea and many more. The space travel with the solar system as spaceship appears in Fritz Zwicky: "Entdecken, Erfinden, Forschen im morphologischen Weltbild", p. 237. Image source: windows.ivv.nasa.gov/ .


Rockets on the sun


Prominence The submitted proposal suggested to modify this idea in a less ambitious way. Instead of generate the energy ourselves, the idea is to make use of already existing "rockets on the Sun" which are now nearly canceling each other and to which we will come back later on. The still horrendously ambitious aim is to accelerate slightly the Sun and so of the Earth just enough so that the asteroid will miss. The later will be less influenced by the displacement because it is farer way from the Sun. Fine tuning in the next few hundred years should then assure that planetary orbits of the solar system become not disturbed too much by this acceleration.
Footnote: Modifying Zwicky's idea to avoid an asteroid impact is a bit far fetched indeed. However, there could be other applications. Image source.



Illustration added 2006 from video by JAXA's Hinode spacecraft. more info
Missing orders of magnitudes


sun Human technology does not allow the production of enough energies for such an idea. Many orders of magnitudes are missing even with a full control of fusion energy. To see the difficulty, consider the magnitudes. The Sun weights 2 10 30 kilograms. Even if it would be possible to redirect the entire solar wind which ejects 1017 kilogram per year into one direction, this would displace the Sun only 1 meter in one year. On the other hand, the radiation energy produced by the Sun is 4 10 33 erg/sec and could in principle be used to accelerate the Sun to a velocity of 100 m/sec in one year, when considering the energy only. By heating and cooling different parts of the Sun and redirect the radiation asymmetrically, a fraction of this energy could in principle be available. But even if the entire radiation could be redirected into one direction, the force would accelerate in one year the Sun only to a speed of 10 -3 cm/sec. The reason for this low value is that photons do not carry a lot of momentum. How is it possible to turn more radiation energy into kinetic energy of massive particles?
Footnote: How many orders of magnitudes are missing is not clear but the question is worth a serious discussion. While the numbers in this essay should be correct, the conclusion is rather optimistic. Some fantastic mechanisms and an incredible better understanding of solar burning is needed to make a control of the solar fission a theoretical reality.


Giant solar flares


Flare Giant solar flares were a long standing enigma of astrophysics. As a matter of fact, these coronal mass ejections are the most energetic phenomena which occur in our solar system [3], exceeding over short times the radiation energy of the Sun. Moreover, their energy is mainly kinetic energy of particles. It has been realized that giant solar flares can produce 1034 erg's, carried away by electrons or more massive particles. When such large solar flares were observed in 1991 for the first time, they were named "giant solar flares" since they were up to 1000 times larger than the ones seen previously. It was then also surprising to see that several giant flares can occur in a single active region within a short time. Still, using natural flares as "rockets" is not sufficient because despite a gigantic energy release, the mass of the ejected material is small. A single flare accelerates the Sun only to 10-7 cm/sec. Enhancement by several orders of magnitudes is achieved by manipulating the nonlinear processes of the photospheric dynamo and the magnetic dynamics in the corona. This is realistic because small instabilities can trigger the energy release during a flare. Tiny small energies can control the subtle bifurcation mechanisms responsible for the flares. The point is that those energies are in the realm of human technology.
Footnote: Solar flares act as rockets and are the most energetic events which happen in our solar system. Whether solar flares can ever be controled with human technology is not clear. Image source: www.pnl.gov .


Asymmetric radiation


flare As a first step it was proposed to produce a resonance in the nuclear reaction through stimulation with neutron beams which are shot to specific parts in the core of the Sun, where the nuclear burning happens. Achieving this goal would be impossible if not fortunately, the energy production of these nuclear reactions were extremely sensitive to the temperature [1]. Monitoring and amplifying the naturally occurring temperature instabilities allows to trigger small temperature changes in the treated region. This produces an asymmetric thermonuclear burning which implies asymmetric radiation and more importantly, an asymmetric convection.
Footnote: the idea in physics that resonances allow small energies to built up large energies is correct. Whether it will ever be possible to monitor and control nuclear reactions in the sun is not clear. Image source: NASA .


Triggering more flares


Flare The asymmetry is unstable and could not be kept alive for a long time if not the Sun's atmosphere above the treated region could be kept to be an "active region". In order to deal with this, strong lasers pointing to specific parts of the photosphere stimulate or suppress super giant flares by influencing the energy convection through the photosphere which lies below the hot chromosphere of the Sun. The flares will be produced in high altitudes of the atmosphere so that the particles, mostly electrons and protons but also heavier ions are shot away from the Sun. Most of the energy is carried away by kinetic energy. The momentum change coming from those artificially triggered flares at specifically controlled active regions together with the enhanced radiation should propel the Sun, a few meters a year at first and finally, after years of tuning, to several hundred meters per year.
Footnote: this modification was necessary because the photon pressure would be far too weak for propelling the sun. That a mechanism similar to ion rockets could work is more reasonable. It adds however more difficulties. Image source: nasa .


Targeting the North Pole


The Sun is not spinning as a rigid body but different altitudes rotate with different speed. This differential rotation would make it difficult to achieve an acceleration in the planetary plane. This is the main reason why it is proposed to accelerate the Sun normal to the planetary plane. Treating the north part of the Sun near the axes of rotation has also other advantages. First of all, it enhances already existing coronal holes, the natural main corridors through which particles of the solar wind escape from the Sun. Also, the pole region can be accessed at any time of the Earth year. Finally, the existing solar wind is already much faster near the polar regions than at the equatorial latitudes. An "environmental bonus" is that the tremendously increased solar wind will not be blown into the direction of the Earth.
Footnote: we have learned that any technology also comes with risks. Changing the fission in the sun would be no exception. And one would have to keep this in mind. [July 12, 2012: Animation of a Solar X-flare blast heading toward earth from spaceweather.com, hitting the earth on July 14th.


Diving away


If a control and amplification of the "hybrid photon-particle rocket on the Sun" really works with the desired intensity, the Earth could "dive away" from the asteroid because the orbit of the minor planet is sufficiently sensitive to changes of the positions of the planets. The minor planet which will pass close to Mars before deflected towards the earth will become redirected slightly away and get a slight kick "upwards" to pass above the North Pole of the Earth. The expectation is that treating the Sun for 30 years from now starting in 10 years would be enough for a success.
Footnote: it is likely that if one would manage to achieve such a thing, a simpler solution could be realized. But let's continue anyway.


Implementation steps


Mercury Should the proposal get approved, huge engineering efforts will be necessary. Plans for building powerful particle accelerators and lasers on Mercury and a network of observation satellites orbiting the Sun are in discussion. Mercury is suited because it is the planet nearest to the Sun and because it has enough iron for building the large magnets for the accelerators. Despite being so close to the sun, it will be crucial to compute fast from the observations the necessary control steps and to overcome computationally the minute long telecommunication delay. Fortunately there has been progress in controlling nonlinear partial differential equations building on older ideas for ordinary differential equations [2].
Footnote: working from Mercury sounds reasonable. Looking however at the current obstacles only to land robots on mars, this part could even pose a major problem. Image source: www.solarviews.com .


Summary and Zwicky's dream


Zwicky In summary, the conference findings are that human knowledge of plasma, nuclear, particle and solar physics as well as the mathematics of partial differential equations might allow a minor human control of the dynamics of the solar system. This technology could help to keep the Earth free from larger asteroid impacts. And who knows whether maybe, one day, Zwicky's crazy dream will come true to make space travel by displacing the whole solar system!
Footnote: It is quite reasonable that Zwicky's crazy dream will appear less crazy in a few hundred years.


Bibliography


1 Internet online library. Nuclear reactions in the sun World science foundation, 2040. http://www.library.org/astro/sun/nuclear/
2 Internet online library. Partial differential equations. World science foundation, 2043 http://www.library.org/math/pde/control/.
3 Internet online library. Solar flares. World science foundation, 2045. http://www.library.org/astro/sun/flares/.
4 Internet online library. Minor planets. World science foundation, 2046. http://www.library.org/astro/celestial/minorplanets/.
5 F. Zwicky. Discovery, invention, research through the morphological approach. Available online in http://www.library.org/astro/people/zwicky/, 1969.
The URLS in the above bibliography are fictuous. It is reasonable to assume however that in 50 years, much of human knowledge is freely accessible from every computer. The book 5) exists and contains the idea of Zwicky. Below are some effective links (valid January 2000).
Some Links: Asteroids Sun Zwicky Lasers Mercury
© 1999-2000, www.dynamical-systems.org www.dynamical-systems.org Logo