Talk:Heliosphere

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[edit] Pic of the day

The image Image:Voyager 1 entering heliosheath region.jpg is due up as Wikipedia:Picture of the Day on Sunday and so will also be shown on the Main Page. This picture illustrates a range of related articles, but I've decided that Heliosphere is probably the most useful primary link.

The associated caption is at Wikipedia:Picture of the day/August 21, 2005. The caption is normally based on excepts drawn from the illustrated article, but in this case I've had to take snippets from several different places. Hopefully, someone editing this page, can take a look at the caption and make sure it still makes sense. In particular it looks like the December 2004 date for Voyager 1 entering the heliosheath may not be universally accepted just yet. -- Solipsist 11:48, 19 August 2005 (UTC)

[edit] Subsonic

How exactly is 250,000 mph subsonic?

  • It is compared to the speed of sound in the material being discussed. In this case the subject is basically a very thin gas. You might have confused the terminology with that of the speed of sound in air at sea level. (SEWilco 04:59, 21 August 2005 (UTC))
  • I was wondering this same thing. Perhaps since the related photo is on the front page and will be prominent for a bit, it would make more sense to either a) change the adjective or b) expain how 250,000 mph is subsonic. It's not very obvious for non-astro-physicists. --JD79 13:41, 21 August 2005 (UTC)

[edit] Rotational Period

On the main Sun entry, the rotational period for the sun is shown to range between 25 and 35 days, but a full rotation is 28 (see opening paragraph of the Sun#Structure section.) I'm assuming that the 27 on this entry refers to the 28 on that entry (or vice versa.) I don't know which one is correct (if either) but I'd just like to point out the discrepancy. Tonytnnt 06:21, 5 March 2007 (UTC)

[edit] contradictory information

Firstly there should be a consensus on the spelling of Voyager 2, in this article it uses both Voyager 2 and Voyager II, I believe the correct usage is the numeric (Voyager 2).

Also exactly when Voyager I passed through the termination shock is contradicted within the article. The worst paragraph is the one below which contradicts the article and is badly written therefore I'm suggesting removing it completely but leaving the old version here.

In May 2005, it was announced that Voyager 1 had crossed the termination shock and entered the heliosheath in December 2004, at a distance of 85 AU. In contrast, Voyager II began detecting returning particles suggesting it was entering the termination shock when it was only 76 AU from the sun, in May 2006. This implies that the heliosphere may be irregularly shaped, bulging outwards in the sun's northern hemisphere and pushed inward in the south.[5] Master z0b 05:33, 5 September 2007 (UTC)

This contradicts the previous statement "In May 2005, NASA announced that Voyager 1 had crossed the termination shock and entered the heliosheath in December 2004, at a distance of 94 AU. An earlier report that this had occurred in August 2002 (at 85 AU) is now generally believed to have been premature." now I'm no scientist so I don't know what the general consensus is. Master z0b 05:37, 5 September 2007 (UTC)

·There is another contradiction. In one spot the article states that Voyager 1 entered the heliosheath in 2004, while a little ways down, it gives a 2006 date. 96.32.132.115 (talk) 04:20, 7 April 2008 (UTC)Steve

The 2nd reference should have been 2006. So now I think they match fairly well considering that the termination shock boundary fluctuates. The 1st reference suggests Dec 2004 and the 2nd reference suggests it was a done deal by May 2005. -- Kheider (talk) 05:30, 7 April 2008 (UTC)

[edit] consistency ?

The 2nd paragraph talks of 10 billion miles, then kilometers per hour. Shouldn't the article use the same units (miles/kilometers) throughout? —Preceding unsigned comment added by 169.3.168.209 (talk) 17:26, 18 September 2007 (UTC)

[edit] Speed of sound

In "Outer structure" the speed of sound is stated as 340 m/s, while in "Termination shock" it is 100 km/s. Which one is correct? (seems like 100 km/s, but I am not sure...) Reminiscenza 20:42, 8 October 2007 (UTC)

[edit] "outer border of the solar system"?

The article, in its discussion of the Voyager findings, hints that the heliopause might be 70 - 94 AU from the Sun. Another quote states that the bowshock (outside the heliopause) is perhaps 230 AU away.

This is far less than the aphelion of many long-term comets. It is also far less than the aphelion of Sedna (976 AU, according to the Wikipedia article on it) and 2000 CR 105 (396 AU) (ditto). Not to mention the hypothetical Oort Cloud, which is 50,000 AU away!

If the heliopause is that close, the "outer border of the Solar System" sentence should be deleted. Captcrisis 02:42, 12 October 2007 (UTC)captcrisis

[edit] WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 09:54, 10 November 2007 (UTC)

[edit] Temperature of the termination shock?

According to "http://www.reuters.com/article/scienceNews/idUSN1044867120071211?sp=true",

Voyager scientists had expected the temperatures within the termination shock to be about 1,000,000 degrees Fahrenheit (555,500 C) as material normally slows down and is heated up when it encounters an obstacle in a normal shock wave. But according to Edward Stone of California Institute of technology, the temperatures registered were much lower, at around 200,000 degrees F (111,100 C). Also, Voyager 1 made only one crossing into the termination shock while Voyager 2 has made at least five shock crossings over several days which allowed them to collect more data.

What does this mean? How can one measure temperature in space -- and what do such high temperatures mean? Chip Unicorn (talk) 18:20, 12 December 2007 (UTC)