The Ulysses spacecraft completed two orbits through the solar system during which it passed over the Sun’s south and north poles.
Its measurements of the solar wind speed, magnetic field strength and direction, and composition have provided us with a new view of the solar wind.
Ulysses was retired on June 30, 2009.
The most striking aspect of this visual interpretation is the asymmetric nature of the Solar Wind which suggests the Sun exerts a particulate repulsive Push via the Solar Wind plasma streams which then [simultaneously] exerts a confining electromagnetic Pull.
The solar wind is a stream of plasma released from the upper atmosphere of the Sun.
It consists of mostly electrons and protons with energies usually between 1.5 and 10 keV.
The stream of particles varies in density, temperature, and speed over time and over solar longitude.
These particles can escape the Sun’s gravity because of their high energy, from the high temperature of the corona and magnetic, electrical and electromagnetic phenomena in it.
The solar wind flows outward supersonically to great distances, filling a region known as the heliosphere, an enormous bubble-like volume surrounded by the interstellar medium.
A NASA publication from 1981 [which describes The Sun as a Magnet] clearly illustrates how the Sun [literally] spins its electromagnetic plasma web which entrains celestial objects [out to 121 AU] within the enveloping Heliosphere.
Spiral Patterns in Interplanetary Space.
The interplanetary magnetic field makes a spiral pattern as the Sun turns.
Pie-shaped “sectors” between the curved black lines are regions where the magnetic field has a consistent direction, its lines of force pointing either away from or toward the Sun (denoted by plus and minus signs, respectively).
Illustrated here are measurements made by the IMP-1 (Interplanetary Monitoring Platform 1) spacecraft during three 27-day solar rotation periods beginning in late 1973.
Each plus or minus denotes the direction of the field according to three hours of IMP-1 data.
Outermost circle of plus and minus signs (with December dates) represents the first 27-day period; the two circles within represent the next two periods in succession.
Comparison of data from one circle to the next shows that the sector structure persisted over most of the long interval of observation.
The heliosphere is the region of space dominated by the Sun.
Plasma “blown” out from the Sun, known as the solar wind, creates and maintains this bubble against the outside pressure of the interstellar medium, the hydrogen and helium gas that permeates Milky Way Galaxy.
The solar wind flows outward from the Sun until encountering the termination shock, where motion slows abruptly.
The interplanetary magnetic field, showing the solar wind flow (red lines), the magnetic field lines (blue lines), and the neutral current sheet (green dotted line)
The Institute of Geophysics and Planetary Physics – University of California Riverside
Voyager 1 became the first spacecraft to cross the heliopause in August 2012, then at a distance of 121 AU from the Sun, although this was not confirmed for another year.
The orbits of the entrained objects [surfing a path of least resistance] are thus primarily governed by the particulate repulsive Push of the Solar Wind plasma streams [which limits perihelion] and the electromagnetic Pull of the Solar Wind plasma streams [which limits aphelion].
The Parker spiral at solar minimum. Source: Alfvén (1977), from Schwenn (1991).
EIKE – Europäisches Institut für Klima und Energie
As the Sun rotates, its magnetic field twists into a Parker spiral, a form of an Archimedean spiral, as it extends through the solar system.
This phenomenon is named after Eugene Parker’s work: he predicted the solar wind and many of its associated phenomena in the 1950s.
The spiral nature of the heliospheric magnetic field had been noted earlier by Hannes Alfvén, based on the structure of comet tails.
The influence of this spiral-shaped magnetic field on the interplanetary medium (solar wind) creates the largest structure in the Solar System, the heliospheric current sheet.
Parker’s spiral magnetic field was divided in two by a current sheet, a mathematical model first developed in the early 1970s by Schatten.
It warps into a wavy spiral shape that has been likened to a ballerina’s skirt.
Johannes Kepler published his first two laws about planetary motion in 1609, having found them by analyzing the astronomical observations of Tycho Brahe.
Kepler’s third law was published in 1619.
The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.
This captures the relationship between the distance of planets from the Sun, and their orbital periods.
Low Latitudes Low Speed Plasma Stream
The low latitudes section of the Solar Wind plasma stream [plus or minus 7.5 degrees around the Solar Equator] generates a slow speed particulate stream of ion pairs.
The asymmetrical nature of this plasma stream is clearly visible because only one side [left side of the diagram below] of this plasma stream connects to the interplanetary magnetic field.
This Solar Wind stream appears to primarily control equatorial objects in the Heliosphere.
The interplanetary magnetic field (IMF) is the solar magnetic field carried by the solar wind among the planets of the Solar System.
In the case of physical ionization of a medium, such as a gas, what are known as “ion pairs” are created by ion impact, and each pair consists of a free electron and a positive ion.
Mid Latitudes Medium Speed Plasma Stream
The mid latitudes section of the Solar Wind plasma stream [between (plus or minus) 9.90 and 21.76 degrees around the Solar Equator] generates a medium speed particulate stream of ion pairs.
The asymmetrical nature [Left-Right and North-South] of this plasma stream is clearly visible with:
a) A faster stream of plasma being generated on the right side in the image below.
b) A predominantly inbound [blue] connection to the interplanetary magnetic field in the South and a predominantly outbound [red] connection in the North.
This Solar Wind stream appears to primarily control objects in the Kuiper Belt.
The Kuiper belt, sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun.
The Kuiper belt is quite thick, with the main concentration extending as much as ten degrees outside the ecliptic plane and a more diffuse distribution of objects extending several times farther.
Overall it more resembles a torus or doughnut than a belt.
High Latitudes High Speed Plasma Stream
The high latitudes section of the Solar Wind plasma stream [above (plus or minus) 21.76 degrees around the Solar Equator] generates a high speed stream of particulate ion pairs.
The asymmetrical nature of this plasma stream is clearly visible with a predominantly inbound [blue] connection to the interplanetary magnetic field in the South and a predominantly outbound [red] connection in the North.
This high speed Solar Wind stream appears to inflate the Heliosphere out to 121 AU and primarily control objects in the Scattered Disc.
Although the closest scattered-disc objects approach the Sun at about 30–35 AU, their orbits can extend well beyond 100 AU.
This makes scattered objects among the most distant and coldest objects in the Solar System.
The innermost portion of the scattered disc overlaps with a torus-shaped region of orbiting objects traditionally called the Kuiper belt, but its outer limits reach much farther away from the Sun and farther above and below the ecliptic than the Kuiper belt proper.
Because of its unstable nature, astronomers now consider the scattered disc to be the place of origin for most periodic comets in the Solar System, with the centaurs, a population of icy bodies between Jupiter and Neptune, being the intermediate stage in an object’s migration from the disc to the inner Solar System.
Eventually, perturbations from the giant planets send such objects towards the Sun, transforming them into periodic comets.