Talk:Voyager 2

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December 10, 2006 Featured article candidate Not promoted

Contents 1 Neptune Discoveries? 2 Star Trek 5? 3 Voyager 2 trajectory 4 Mariner 12? 5 Alignments? 6 Major cleanup--achieved stub status. 7 Selected anniversary 8 Uranus tilt 9 Cultural References 10 Date of launch 11 Curiosity of phraseology 12 Grammar 13 text source issue 14 Poor choice of words? 15 Ambiguous wording 16 " at a fraction of the money later spent" 17 Where's it headed? 18 Miranda photo 19 Velocity - Expansion request 20 Too much detail in Jupiter section

[edit] Neptune Discoveries?

The Uranus section mentions rings and moons imaged by Voyager 2 around Uranus, but the Neptune section does not mention any rings or moons, even though Voyager 2 discovered several around Neptune. I was wondering, is there a specific reason for this, or is it just an oversight? If it's a simple oversight, I can add that information in. Katzs 20:07, 19 April 2007 (UTC)

[edit] Star Trek 5?

I'd have to watch the awful movie again to make sure, but isn't the probe shot by the Klingons in Star Trek V actually Pioneer 10 or 11? I thought I spotted those two finned RTGs.

You're right, it's one of the Pioneers: there's a shot of the plaque. Was there any visual differences between the two? Seems like I heard that P11 had a second boom of some sort. CFLeon 02:02, 25 May 2006 (UTC)

There was no difference other than on the molecular scale, and the chosen trajectories, between the outer planetary Pioneers. --Chr.K. 19:54, 26 June 2007 (UTC)

[edit] Voyager 2 trajectory

http://nssdc.gsfc.nasa.gov/nmc/tmp/1977-076A-traj.html not as parameters but direct distances to the sun/the planets visited, in case anyone is interested just because I added a similar link to Talk:Voyager 1 and found it hard to find --Deelkar (talk) 05:06, 14 Dec 2004 (UTC)

[edit] Mariner 12?

I seem to recall seeing somewhere that Voyager 2 was initially designated Mariner 11 and Voyager 1 was Mariner 12. It may have been from an article in Science around the time of the launches (1977).--Clemmentine 01:24, 13 Jan 2005 (UTC)

The only corroborating evidence is this PowerPoint presentation: http://www.it.lth.se/Kodningsteknik/lectures/ECCintro.pdf which lists the Mariners in order of launch dates, which does imply Voyager 2 = Mariner 11 (launched in August) and Voyager 1 = Mariner 12 (launched in September).

On the other hand, all other mentions Google finds seem to be taken from Wikipedia, so the evidence is weak in either direction. Gatland's Illustrated Encyclopedia of Space Technology does not say.

Interestingly, Viking was originally called Voyager, at which time Voyager was called Grand Tour.

According to http://home.cwru.edu/~sjr16/advanced/20th_far_voyagers.html, Voyager 1 and 2 were also called "Mariner Jupiter/Saturn A" and "B", respectively, which seems to map to Mariner 11 and 12 better. Urhixidur 05:34, 2005 Jan 13 (UTC)

[edit] Alignments?

Every 175 years or every 200 is not going to make much difference. The synodic periods of Saturn, Uranus and Neptune with respect to Jupiter are 19.88, 13.82 and 12.79 years, respectively. They don't factor well into each other. Those of Uranus and Neptune with respect to Saturn are 45.33 and 35.86 years, and that of Neptune with respect to Uranus is 171.54 years.

If you line up the giant planets (which never happens) and wait 171.531 years, they'll line up again within 40° or so of each other (Saturn would be ahead of Neptune by 31.7° and Uranus behind by 8.5°, Jupiter in between). Urhixidur 00:12, 2005 Jan 14 (UTC)

175 years came from http://voyager.jpl.nasa.gov/science/planetary.html . I've also seen 176 years quoted elsewhere. It's my bad choice of words in using 'alignment' when I should have used something like 'geometric arrangement'. I'll fix that. Thanks for pointing that out.--Clemmentine 01:33, 14 Jan 2005 (UTC)

[edit] Major cleanup--achieved stub status.

I've done a major cleanup. Gone is the Voyager Golder Record (linked from Voyager program), Launch/Jup/Sat/Ur/Neptune all have different sections now. Science result unique to Voyager 2 (not Voyager 1) added, should have science section in Voyager program.

Began decent Uranus and Neptune sections, as Voyager 2 is the only craft to visit these planets.

See talk in Talk:Voyager program.

[edit] Selected anniversary

An event mentioned in this article is an August 20 selected anniversary. No it isn't! But, it's listed on the (IMHO) rather arbitrary date August 24, when the probe in 2003 "was 71 astronomical units distant from Earth". Why is this date important at all? -DBrane 08:34, 26 May 2005 (UTC)

[edit] Uranus tilt

"Uranus has an Axial tilt of 97.77°". Reading the definition of axial tilt I don't understand the meaning of a figure greater than 90 degrees.

According to Uranus#Axial_tilt the number greater than 90 degrees is based upon the direction of rotation. (SEWilco 06:34, 25 August 2005 (UTC))

Yep, all planet except Uranus have the same rotation direction as orbital direction (Counter-clockwise looking from the above the North pole of the sun), and theories of solar system formation say they should be the same, so whatever hit Uranus knocked it more than 90 degs off axis. Angles above 180 don't make any sense though. JamesHoadley 10:23, 26 August 2005 (UTC)

[edit] Cultural References

This is minor compared to the other problems, but the same three cultural references attributed to Voyager 2 are attributed to Voyager 1 on the Voyager 1 page.

They're not now! I didn't delete it and I've never seen it like that. The Voyager program page does have some different ones. Remember to sign your messages on talk pages with ~~~~. JamesHoadley 14:12, 28 February 2006 (UTC)

I'm ereasing the references to the YTMND sites. I like YTMND, but we don't need to clutter every article with every random YTMND that is made. Nanded 00:09, 6 May 2006 (UTC)

[edit] Date of launch

Was Voyager 2 launched a month before Voyager 1? Because that's what wikipedia is telling people. --82.29.226.251 20:49, 14 August 2006 (UTC)

Yes, that was the case. Voyager 1 was (and still is) faster so it reached Jupiter well before Voyager 2.--JyriL ^talk 20:53, 14 August 2006 (UTC)

[edit] Curiosity of phraseology

At present [15:33 GMT 25/8/06] this article uses the phrase "when every major planet in the solar system had now been visited at least once by human-made spacecraft."
Does this imply that there is evidence that some/all have been visited by extra-terrestrial craft, and if so what is the citation, please ? -- Simon Cursitor 15:34, 25 August 2006 (UTC)

[edit] Grammar

The last sentence of the Jupiter section doesn't match the text when I try to edit it. In the article the grammar and spelling are terrible but when I go to the edit section, everthing is correct. Someone with more power please edit.161.184.182.112 09:39, 7 December 2006 (UTC)

[edit] text source issue

Certain fragments of the article have been apparently taken from the narrative of BBC's The Planets series, episode 3: Giants. I wonder if it's fine with Wikipedia principles... ;-) Ijon-Tichy 22:58, 15 December 2006 (UTC)

Well, copyright violation certainly isn't one of Wikipedia's principles. Tell me, is the violating text from this edit? Anonymous editor User:83.30.32.137 added a whole chunk of literary-type text in two edits, that could be what your talking about. --JamesHoadley 11:08, 16 December 2006 (UTC)

I don't recognise the fragments you have provided. However, I did recognise other ones immediately - the tables below make up a comparison of the original BBC and Wikipedia versions (left side and right side, respectively), fragment by fragment. That's all I have managed to track down.

Voyager revealed an atmosphere of hydrogen and helium gas, whose clouds were much more dynamic than had been imagined. Jupiter's winds gust at hundreds of miles per hour, and the red spot alone is three times the size of the Earth - the greatest storm in the Solar System). Voyager hinted at why this should be - it found that Jupiter gives out twice as much energy as it receives from the Sun, suggesting that its core must be hot. Scientists now believe that at the heart of this massive planet, the gases are compressed until they become a metallic liquid. This hot and churning core could be the powerhouse that drives Jupiter's winds and, like a dynamo, creates the enormous magnetic field around the planet.

Voyager's cameras revealed an atmosphere of hydrogen and helium gases, whose clouds were much more dynamic than had been imagined. Jupiter's winds gust at around hundreds of miles per hour, and the red spot alone is three times the size of the Earth (some people have referred to this as the greatest storm in the Solar System). Voyager found why this should be - it found that Jupiter radiates twice as much energy as it receives from the Sun, suggesting that its core must be hot. Scientists now believe that at the heart of the planet, the gases are compressed until they become a metallic liquid. This hot and churning core could be the powerhouse that drives Jupiter's winds and, like a dynamo, creates a huge magnetic field around the surface of the planet.

As the Voyager encountered the planet itself, it found that Saturn was made of the same gases as Jupiter. These two worlds are the great gas giants of the solar system, dwarfing all the other planets. Yet Saturn held mysteries of its own. Saturn is smaller and colder than Jupiter, it generates less heat within, and receives less energy from The Sun. Yet Voyager recorded even faster winds on Saturn than on Jupiter - a 1000 miles an hour. Why this should be, was not yet understood.

As the Voyager craft encountered the planet itself, it was revealed that Saturn was made of the same gases as Jupiter. These two worlds are known as the great gas giants, dwarfing all the other planets. However, Saturn held mysteries of its own. Saturn is smaller and colder than Jupiter, it generates less heat within, and receives less energy from The Sun. Yet Voyager recorded even faster winds on Saturn than on Jupiter (around 1000 miles an hour). At the time of this discovery, why this should be, was not yet understood.

Ijon-Tichy 13:09, 17 December 2006 (UTC)

OK, this seems to have been done by two editors, the 2 Jupiter paragraphs (plus another) by User:217.37.214.57 here, and the Saturn paragraphs (plus some Neptune text) by User:84.65.34.122 here. User:217.37.214.57 also did this and this edit. I guess we wait for 24 hours for anyone else to chime in then delete these edits. I've seen The Planets, and this prose seems like the sort of naration in that series. --JamesHoadley 17:30, 18 December 2006 (UTC)

I've notified the Copyright violations people, see Wikipedia talk:Copyright problems#Possible_copyvio_on_Voyager_2.2C_from_video here. --JamesHoadley 13:23, 19 December 2006 (UTC)

I've just removed all edits by User:217.37.214.57 and User:84.65.34.122 in this article, justification being that one user was able to cite whole chunks that matched up with The Planets series, I've seen this series ages ago and it seemed vaguely familiar, and all paragraphs by these users that Ijon-Tichy didn't cite were consistent with ones he/she did. --JamesHoadley 09:39, 4 January 2007 (UTC)

[edit] Poor choice of words?

"Fortunately, the mission team was able to fix the problem--caused by overuse that temporarily depleted its lubricant--and the probe was given the go-ahead to examine Uranus."

I'm gonna go out on a limb and say whoever added that line in worded it as such as a joke. Funny funny.

--- Can anyone confirm this statement? I can't seem to find it anywhere on the web. Perhaps this doesn't belong in the article. --Borisborf 05:06, 1 August 2007 (UTC)

These sites mention the problem:

http://space.about.com/od/voyagermissions/p/voyager2.htm

http://solarsystem.nasa.gov/missions/profile.cfm?Target=Saturn&MCode=Voyager_2

Andy120290 06:00, 1 August 2007 (UTC)

[edit] Ambiguous wording

"Ground crews... forgot to send an important activation code to Voyager 2. This caused the probe to shut down its main high-gain antenna. Fortunately, ground crews were able to establish contact through the craft's low-gain antenna and activate it."

Does this mean they were able to activate the high-gain antenna? Or just that they were able to establish contact soley by low-gain? 81.157.0.17 01:05, 26 May 2007 (UTC)

I changed it to "... low-gain antenna and reactivate it." The HGA shut down, so ground communicated with the still active LGA, and commanded Voyager 2 to reactivate it's HGA. I don't have a source, but the HGA was working for the rest of the trip. -- JamesHoadley 10:46, 3 July 2007 (UTC)

[edit] " at a fraction of the money later spent"

does this sentence account for inflation?--87.168.67.204 09:16, 3 July 2007 (UTC)

I don't know the cost of the mission, so I put a citation needed mark next to it. It's probably true (Voyager 2 was probably cheaper than Galileo and Cassini, because it's simpler and shared it's development cost with Voyager 1, and it visited 4 times as many planets), but also of little meaning, because the latter probes orbited the planets and returned a lot more data. -- JamesHoadley 10:46, 3 July 2007 (UTC)

The Cassini article says it cost $3.26e9. A quick check of the net finds Voyager 1+2 at $8.65e8. An inflation calculator says the factor from 1975 to 2006 is about 4. So per-probe, the cost of Voyager is about 1/2 of Cassini. Caveats with this kind of thing are that the 1975-2006 may not be the right interval, money was spent over a long period and at varying rates in both projects (need to integrate), and it is a consumer price index-based estimate, where we are talking about military/aerospace stuff. But it's extremely likely the general conclusion is valid: mass production, even of 2 units, is more economical than one-off stuff. Can you imagine the disaster had Cassini exploded on the pad? Mars Observer was bad enough. mdf (talk) 13:47, 7 December 2007 (UTC)

[edit] Where's it headed?

Article should state where it's going. An obvious question many readers will wonder. Tempshill 05:04, 6 September 2007 (UTC)

[edit] Miranda photo

Could someone add the remarkable Miranda photo mosaic (I think it's a mosaic) to the gallery of Uranus photos in this article? Tempshill 05:04, 6 September 2007 (UTC)

	It is requested that a photograph or photographs be included in this article to improve its quality.
	The Free Image Search Tool (FIST) may be able to locate suitable images on Flickr and other web sites.

[edit] Velocity - Expansion request

• 1: What is the vessel's current velocity?
• 2: Is it still accelerating?
  • 2a: If so, at what rate?
  • 2b: If not, when did it stop?
• 3: What propelled/propells the craft?

The above is either missing from the article or somewhat unclear. One would think that the velocity of the vehicle would be something important enough to make clear in the LEAD or an infobox. MrZaius^talk 17:10, 29 November 2007 (UTC)

It's on a hyperbolic orbit (escape orbit). So its current velocity is always decreasing but not to zero. It most recently stopped accelerating (i.e., its acceleration became negative) at its closest approach to Neptune (August 25, 1989). The craft was propelled by a rocket at launch and orbit insertion; since then it has been unpropelled (in free fall -- its motion controlled only by the gravitational field).

Given that its current velocity (and (negative) acceleration) is changing, it doesn't seem all that practical to put it into the article. Then again, the current position is mentioned (in "current status"). There's also a link to a site with more detail. Paul Koning 15:17, 30 November 2007 (UTC)

[edit] Too much detail in Jupiter section

The Jupiter section has too much background detail about Jupiter itself. It should be limited to Jupiter in relation to Voyager 2 (dates of flyby, moons visited, discoveries made by Voyager 2 specifically). See Voyager 1#Jupiter for a better model. --IanOsgood (talk) 18:56, 9 December 2007 (UTC)

Agreed. Removing text, specifically because it appears to still contain unsourced material. -L4N —Preceding unsigned comment added by Loser4Now (talk • contribs) 15:28, 12 December 2007 (UTC)