Talk:Solar wind
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[edit] Why and discovery
whay? is there a solar wind..... who has discovered it.
This is a difficult question. Observations of cometary tails pointing away from the Sun date back to the first millenium BC. Some sources cite Chinese astronomers to have postulated the existence of a solar life to explain this. Kepler talked about sunlight pressure in the 17th century to explain this. Ludwig Biermann came up in 1951 with the idea of a supersonic wind blowing from the Sun with a speed of the order of 1,000 km s-1, but did not come up with any mechanism for this acceleration. After the realization that Chapman theory of the solar corona in hydrostatic did not work (because it predicts an interstellar pressure orders of magnitude too large), Eugene Parker came up with his classical solution in 1958. USferdinand 07:42, 17 January 2007 (UTC)
[edit] Earth temp and solar winds
is there any relation between the temperature of the earth and solar winds?
No, for two reasons. Firstly, most of the sun's outputted energy is in the form of photons, not particles. Secondly, the solar wind is almost completely deflected by the Earth's magnetic field. If it wasn't, we'd be bombarded by ultra-high-energy particles, develop cancer, and die. This is why space ships have to be well shielded; even so, there is some risk of excess radiation exposure to astronauts. Ckerr 08:57, 3 November 2005 (UTC)
There are relationships between the temperature of the atmosphere and the aurora, but only in specific areas, not in the atmosphere as a whole. The subsolar point of the Earth - the region beneath the sun, receiving the greatest amount of heating - can never cover both poles sufficiently to provide as much energy there as the aurora do. In addition, on the nightside, there's no solar heating, asides from conduction. The aurora occur close enough to the highly conducting thermosphere to allow an effect to be seen there. To really see an aurora creating havoc with a planetary atmosphere, though, you need to go out to Jupiter, where an aurora providing 100x as much energy as that of the earth mixes with a far reduced solar photon flux (about a quarter of that at Earth) and so has a more pronounced effect. At Saturn, an aurora of comparable power input to that of the Earth exists in an even lower solar photon flux. This gives an indication of the relative power inputs of the sun and the aurora. Modeled auroral oval. However, the origin of the various aurora are not necessarily all connected to the solar wind. The solar wind acts as a dynamo, creating currents that drive other sources of high energy particles into the atmosphere. At Jupiter, this is a very weak effect due to a massive magnetospher deflecting particles, whereas at Earth it is the dominant effect. Other planets differ. MilleauRekiir 17:37, 25 August 2006 (UTC)
[edit] Wind carrying magnetic field
The idea of the solar wind carrrying the sun's magnetic field with it is wrong. Electric currents create magnetic fields. The solar wind is creating its own magnetic fields and interacting with the existing solar magnetic field.They are locked in a feedback loop.
The current is set at the solar surface, when the wind is emitted. The magnetic and electric environment is confined by the fact that the emitted particles are in a plasma, therefore the wind carries out the signature of the solar magnetic field as it is just another part of the outer plasma of the Sun, just an unconfined, radially flowing one. MilleauRekiir 17:14, 25 August 2006 (UTC)
[edit] Plasma is not a gas
Plasma is not a gas. Plasma follows its own rules just as a gas behaves differently than a solid.
Comment: I was under the impression that it is debated whether it should be classified as it's own form of matter. 143.195.150.63
[edit] Mass loss
The total amount of mass lost by the Sun due to solar wind is about 600,000 tonnes per second. The figure of 800 kg/s cited above is clearly wrong. The density of the solar wind at 1 A.U. (7 protons per cubic cm, (or 7*10^6 protons/cm^3), the surface of an sphere with such a diameter (2.5 10^22 m^2) and the average solar wind speed of 400 km/s (4*10^5 m/s)lead to an estimate of about 7*10^35 protons per second leaving the Sun, or 1 million tonnes per second. I have a figure of 600,000 tonnes per second coming from a paper which I cannot find right now. 149.217.1.6 10:37, 6 September 2005 (UTC) J. R. Crespo Lopez-Urrutia
- You were right, the correct mass loss rate is about 1E9 kg/s according to Wood, B. E.; Müller, H.-R.; Zank, G. P.; and Linsky, J. L.; 2002, Measured Mass-Loss Rates of Solar-like Stars as a Function of Age and Activity, Astrophys. J., 574, 412-425
- Urhixidur 21:00, 2005 September 6 (UTC)
[edit] "formation of distant stars"
Article's intro says that solar wind can explain "formation of distant stars" but I see nothing in article body on the subject. If it's a true statement, should add text about it or at least a link; otherwise delete.FRS 17:28, 12 October 2005 (UTC)
- My only guess is that it refers to the stellar winds of very massive stars and star clusters, which can significantly influence the nearby ISM. There are now many, fairly clear cases of past generations of stars that have created bubbles in the ISM, compressing the surrounding material enough to trigger star formation. However, in most cases that I can think of, it would be difficult to separate the effect of the stellar winds from that of supernovae in such regions. Both will have a similar influence.
- After being redirected here from stellar wind and reading this page, I wonder if stellar wind shouldn't be a separate entity that talks more about winds from massive stars and from other stages of stellar evolution. In particular for massive star winds, the mechanism is not due to a corona but to radiation pressure from the incredibly larger luminosities at the surfaces of these stars. mh 04:17, 23 March 2006 (UTC)
[edit] Question: Formation of heavy isotopes of hydrogen in solar wind?
I just thought about this: Could solar wind be a significant source of the formation of heavy isotopes of hydrogen by the fusion of high velocity protons and neutrons? The small proportion of neutrons in solar wind should follow a newtonian trajectory, while the protons follow one that is also influenced by magnetic fields. There is thus the possibility of collisions between these two particles. This might be more likely when the protons are within the influence of the magnetic fields of planets, as this would cause the protons and neutrons to follow quite different paths and thus accelerate relative to each other. If this mode of fusion is exothermic it might account for some of the 'unknown' energy that accelerates the solar wind that the article refers to. Any opinions?--ChrisJMoor 03:11, 10 February 2006 (UTC)
They would intially both follow radial paths from the Solar surface. When interacting in a shock boundary, the neutrons would interact at a shock developing in response to the atmosphere, whereas protons are trapped outside the magnetosphere, some distance behind. Although it would be more likely to happen as the neutrons pass through the proton shock, the high energies and low densities involved would both work against the initial combination. The high temperature of the plasma would also threaten to distabilise the produced atom. For heavier isotopes, the entire process would have to happen more than once. If we're considering this to be happening in a proton shock, it would be more likely for more protons rather than more neutrons to join and create helium 3 rather than say deuterium. Its difficult enough for this to happen at the densities represented by the upper atmosphere, never mind the outer magnetosphere, but the massive numbers mean there'll probably be a little... MilleauRekiir 17:21, 25 August 2006 (UTC)
- Deuterium says "Stellar fusion destroys deuterium, and there are no known natural processes (for example, see the rare cluster decay), other than the Big Bang nucleosynthesis, which might have produced deuterium at anything close to the observed natural abundance of deuterium." Helium-3 mentions "helium-3 is thought to exist on the Moon (embedded in the upper layer of regolith by the solar wind over billions of years)". (SEWilco 04:35, 16 April 2007 (UTC))
[edit] Farts in the martian atmosphere?
Mars's atmospheric pressure makes one's farts more condensed, therefore causing a stronger and more pungent aroma, especially when solar winds blow it around.
Should this section really appear in this article? It sounds like a joke. Init 19:49, 15 April 2007 (UTC)
It shouldn't be, I will remove it if its still in there! GB 04:15, 16 April 2007 (UTC)
[edit] needs quantitative estimate
How many newtons per square meter could solar wind exert on an object at 1 AU from the sun, outside earth's magnetic field?
- I just did some calculations, if I made no major errors: starting from 10^6 t/s mass loss, the earth r=6300 km with area pi*r*r in 149.6*10^6 km distance "catches" about 450 g/s of it. Now most of this is in the kinetic energy of the particles (although it is probably not completely absorbed into acceleration due to reflection and heat, but remember we are doing rough estimates here).. sqrt(400g*c*c*2/m_Earth) seems to yield an effect in the magnitude of 10^-4 .. 10^-5 m/s². This is of course basically nothing, but if I remember correctly, planetary orbits are "stable" (ie. once taken they run forever, they lose micro amounts of energy by coupling effects), thus this small "push" can add up since it is not self-correcting? (For a "real" calculation you would have to compare the potential energies between different orbits of the earth, you cannot simply multiply 10^-5 m/s² with seconds, orbits do not work this way) Yes, I did this calculation to find out whether solar wind could be a candidate for the mystery "growing" [[1]] of the AE. Has no one thought of that ever before? If this is potential explanation, the effect should be non-linear, since other planets have different densities and are farther away from the sun. Should be worst with the inner planets. You can comment to areau.gans at arcor de. --145.253.2.238 (talk) 09:07, 16 January 2008 (UTC)
[edit] Question About Mercury's Magnetosphere and the Solar Wind
The entry for Mercury states that it has a magnetosphere strong enough to deflect the solar wind, and that while its low gravitational pull prevents it building up a significant atmosphere, it does have detectable amounts of various gases from a variety of sources. This article implies strongly that the solar wind scours all gases from the planet. There appears to be a conflict. —Preceding unsigned comment added by 76.243.235.134 (talk) 19:17, 26 September 2007 (UTC)
