Talk:Bow shock

Picture

The picture makes it appear like inferno starts after the bow shock. Is there something to this? Is there some kind of interstellar plasma outside this border that will destroy the poor Voyagers? Salleman 12:13, 28 May 2005 (UTC)

Caption for first image says the Earth is too small to be seen on this scale - shouldn't it be the Earth orbit is too small? I'm pretty sure the Voyagers aren't actually bigger than the Sun, and the Sun itself is much smaller than depicted, so the image is not really meant to be to scale. —Preceding unsigned comment added by 87.162.22.135 (talk) 06:54, 17 October 2007 (UTC)

90,000 AU?

"The Earth's bow shock is about 100-1000 km thick and located about 90,000 AU from the Earth." This can't be correct; Perhaps this should be 900000,000 km? Stompbox 21:56, 28 December 2006 (UTC)

 - 90,000 km is less than the distance from the earth to the sun.

From the article: "The best-studied example of a bow shock is that occurring where the solar wind encounters the Earth's magnetopause..." The distance from the earth to the sun-facing side of the magnetopause is roughly 70,000 km. Also, from Magnetosphere, "An additional feature is a collision-free bow shock which forms in the solar wind ahead of Earth, typically at 13.5 RE on the sunward side." 13.5 RE (earth radii) is just over 86,000 km. I'm going to go ahead and make the change. Stompbox 20:36, 3 January 2007 (UTC)

Bow shock vs. Termination shock

I'm posting this in both talk pages because there must be a problem. Both articles mention that their "shock" is the boundery where the solar wind particles slow from supersonic to subsonic speed. Now they can't both be right so at least one of them must be corrected. I am no expert on this so I'll let the experts fix it. 32.97.110.142 13:51, 27 September 2005 (UTC)

Seems to be fixed. Termination shock is where solar wind slows down, bow shock is where ISM slows down --Keflavich 21:26, 12 April 2006 (UTC)

Graphics

Update: I believe the issues have mostly been corrected. (No, the bow shock will not incinerate the Voyagers; hopefully the solar wind/ISM supersonic/subsonic distinctions have been clarified in the article.) Could someone who knows more about plasma astrophysics please verify? Ckerr 10:51, 23 October 2005 (UTC)

Not just astronomy...

The article begins as "In a planetary magnetosphere, the bow shock is the boundary at which the solar wind abruptly drops..." and ends with "Astronomy stubs", as if bow shock is something special just in astronomy, which I think is not the case. Correct me if I'm wrong, but I thought bow shock is a more general aerodynamic (to be precise, fluid dynamic) phenomenon (though I don't know about Termination shock mentioned above). So, could someone add another examples such as reentry vehicles and hopefully revise the article as a general fluid dynamic term? (and perhaps this is to be categorized under Category:Fluid dynamics) - Marsian / talk 13:05, 28 December 2005 (UTC)

Yes, pick up any book on Gas Dynamics or Supersonic Aerodynamics. A bow shock forms ahead of any blunt body passing through any medium (gas, liquid, or solid) at supersonic speed. Now here's a question for you: how is "bow" pronounced? Like "bough" (because it's ahead of the body) or "beau" (because of its curved shape, like a bow for shooting arrows)?--BillFlis 15:32, 30 June 2006 (UTC)

I thought it was called "bow shock" because its shape and behaviour are similar to how water behaves when the front (i.e. bow) of a ship passes through it. Can't source this however (also, haven't tried). 194.187.213.95 21:04, 14 May 2007 (UTC)

This article JUST deals with an astronomical subject. If there are OTHER Bow Shocks than they should be under "Bow Shock (what ever)"aceslead 03:13, 11 August 2006 (UTC)

There is only one concept of the bow shock. This astronomical phenomena is simply an example of this one idea on a large scale. I think that this article should focus on fluid mechanics. This solar wind portrayal of bow shocks may then be listed within the fluids topic as an example of one. Jadias 18:59, 11 January 2007 (UTC)

As an astrophysicist, I second that. Starting the article saying that "In astrophysics, a bow shock is...", as if a "bow shock" had a special definition as an astrophysical subject, is completely funny. There are no "other" bow shocks, all bow shocks are bow shocks in the same sense, as defined in fluid mechanics. The bow shocks presented in this article are just some examples, that happen to be of relevance to astrophysics. The title of the article cannot be just "bow shock". 130.179.72.179 (talk) 21:11, 11 February 2015 (UTC)

Now that the page title has been corrected, I did some refactoring. The article is still pretty poor, but at least it has some structure. 130.179.72.179 (talk) 00:14, 21 February 2015 (UTC)

Stub No More

Astronomy stub should go it should just fall under the category: astronomy.aceslead 03:13, 11 August 2006 (UTC)

Agreed. I am removing the stub. in the future dont worry about removing stubs - if an article seems to define itself and contain enough relevant information, it is not a stub. Just go ahead and remove the stub, and if someone has a problem with that, they will re-add the stub later. --Exodio 01:31, 17 August 2006 (UTC)

New data shows hypothesized bow shock around sun doesn't exist

Recent IBEX data shows that the hypothesized bow shock around the sun doesn't exist. This article should be updated.

http://www.sciencedaily.com/releases/2012/05/120510141957.htm

http://www.sciencemag.org/content/early/2012/05/09/science.1221054 — Preceding unsigned comment added by 216.16.193.186 (talk) 16:06, 11 May 2012 (UTC)

The now edited version states "For several decades, the solar wind from the Sun was thought to form a bow shock when it collides with the surrounding interstellar medium. " - This is incorrect. It was previously thought that the ISM formed a bow shock when encountering the Heliopause. The solar wind already forms a termination shock (on the other side of the heliopause) as is subsequently and contradictingly stated. — Preceding unsigned comment added by 87.194.80.117 (talk) 19:37, 6 May 2013 (UTC)

Flawed discussion of velocities in "Description"?

I'm no expert in this field, but the following in "Description" just doesn't seem to make sense: "At the bow shock, the bulk forward velocity of the wind (which is the component of the velocity parallel to the field lines about which the particles gyrate) drops below the speed at which the particles are corkscrewing."

If something is following a corkscrew path, its speed of progress along the axis of the corkscrew, which I assume is what is meant by "bulk forward velocity" here, is always going to be less than the speed at which it is corkscrewing. Therefore, the conditions for bow shock described in the sentence would apply everywhere for a solar/stellar wind of charged particles in the presence of a magnetic field.

I speculate that there's a problem relating to interpretation of "speed at which the particles are corkscrewing". I read this as "absolute velocity" and I imagine others would do the same.

If I'm correct here, can somebody with more knowledge fix this please?

ColinBrownWD35NY (talk) 12:12, 10 March 2014 (UTC)

You were confused by a poor analogy. You are right that, in a corkscrew motion, velocities around and along the axis are tied. But when charged particles interact with a magnetic field, their motions around and along the magnetic field axis are independent. What the paragraph is trying to say is that, at the shock front, one kind of motion (bulk motion along) is converted into the other (thermal motion around).

→ I changed "corkscrewing" to "gyrating", as used before — Preceding unsigned comment added by 130.179.72.179 (talk) 22:51, 11 February 2015 (UTC)

Pronunciation

How is the "bow" of "bow shock" pronounced? I assume it's "bau" (/baʊ/, like the bow of a ship), but it could also be pronounced as "boh" (like a tied ribbon). Can we add the pronunciation to the lede? — Loadmaster (talk) 18:27, 31 January 2020 (UTC)

I always heard and said it like in NASA ScienceCasts: Cosmic Bow Shocks on YouTube. So /baʊ/, I think. BernardoSulzbach (talk) 22:05, 2 February 2020 (UTC)

Agree. I'd add it to the lede but I don't know how to do that International Phonetic Alphabet stuff. PaddyLeahy (talk) 19:11, 22 January 2024 (UTC)