Talk:4 Vesta

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Good article4 Vesta has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
Good topic star4 Vesta is part of the Asteroid belt series, a good topic. This is identified as among the best series of articles produced by the Wikipedia community. If you can update or improve it, please do so.
On this day... Article milestones
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September 22, 2006Good article nomineeListed
June 1, 2008Featured article candidateNot promoted
September 16, 2008Featured topic candidatePromoted
November 21, 2008Good article reassessmentKept
May 15, 2020Good topic removal candidateDemoted
April 1, 2024Good topic candidatePromoted
On this day... Facts from this article were featured on Wikipedia's Main Page in the "On this day..." column on March 29, 2004, March 29, 2008, March 29, 2009, March 29, 2010, March 29, 2011, March 29, 2012, March 29, 2015, March 29, 2021, and March 29, 2022.
Current status: Good article

Density[edit]

Following [1] (Jan 9, 1998) the density of Vesta is only 3.9 ± 0.3 grams per cubic centimeter. Is this more recent/fiable than the current value of 3.3g/cm3?

Thomson et al. (1997) gives a mean radius of 258 km and Michalak (2000) a Mass of 1.36 ± 0.05 × 10–10 Sun masses. Based on this, Keil (2003) gives a density of 3.8 g/cm^3 -- Epo 10:44, 17 Mar 2004 (UTC)
The old density estimates of even 5.0 or so were based on the IRAS diameter which was far too small. Based on the newer HST data of Thomas [Science 277, p 1492, (1997)], the dimensions are 578x560x458 km ± 10 km, so a geometric average of 529 km, giving a volume of about 7.8±0.4×1016 m3. The latest mass estimate of Pitjeva (ref in article) gives about 2.67×1020 kg, with maybe a 15% uncertainty by comparing to other people's results. This then gives a best estimate of density of 3.4 ± 0.5 (the uncertainty is kind of uncertain). Deuar 08:43, 13 November 2005 (UTC)[reply]

Rewrite[edit]

I reworked the whole article -- please somebody check the grammar since my Engrish is not perfect Jyril 21:27, 22 Jun 2004 (UTC)

After reading through a few papers on the topic, i've tried to put what i've gleaned into the article before I forget it or lose the notes ;-). The end result seems to have been a major reorganisation. Deuar 21:05, 13 November 2005 (UTC)[reply]

History[edit]

Needs some expansion on the discovery, and it's former status as a planet... The fact that it's visible to the naked eye seems like it only had bad luck not being picked as a classical planet. Tesseract501 March 23, 2006.

Needs some expansion on the discovery. Michaelbusch 18:08, 17 Aug 2006 (UTC)

Ceres is still the largest asteroid even though Ceres is also a 'dwarf planet'. Pluto is a Kuiper Belt Object (KBO) even though it is also a 'dwarf planet'.

Diameters[edit]

Regarding the Diameter: What does the third measurement (for irregular shapes) indicate? Am I correct to assume that the first measurement indicates the longest axis at the equator, and the second measurement the polar axis? If so, is the third measurement the secondary equatorial axis (at right angle form the longest equatorial axis)? Or is it the mean diameter or something else? Thanks ---- Tesseract501 March 23, 2006.

I believe it's standard for it to be at right angles to both. kwami 23:59, 23 March 2006 (UTC)[reply]
Thank Kwami. I checked out the info on several other planetoids. The values seem to indicate Triaxial Ellipsoid Dimensions (geometric measurements for irregular objects). From what I can tell, the three numbers only fall in order from longest to secondary to shortest diameter. Whether or not any of the three happen to be the equatorial or polar diameters may be uncertain. It gets even trickier because some asteroids may rotate in more than one direction (wobbling) because of their irregular shape and composition. So I don't know how someone could find that kind of data for the major known asteroids. I haven't found any sources to tell us what the equatorial(s) and polar(s) diameters are for specific asteroids. By the way, whoever put together the data on all the various asteroids did an AMAZING, SUPER JOB. It must be full-time work to keep them all updated. ---- Tesseract501 March 24, 2006.
A hunt for "most out of date solar system body" could be fun ;-) Deuar 16:55, 26 March 2006 (UTC)[reply]

For rotation to be stable over long timescales, the shortest DEEVE diameter must correspond to the axis of rotation and the two others are the major and minor axes of the ellipse formed by the DEEVE's intersection with the equatorial plane. Obviously, all three are at right angles to each other. Almost all objects in single-axis rotation, not tumbling (we can measure this by lightcurve and radar), so we can define the axes properly. 'DEEVE' stands for dynamically-equivalent equal-volume ellipsoid. It is an ellipsoid with equal volume and equal moments of inertia to a given asteroid. Such an object has the same mass, volume, and density as the target asteroid and is the standard for computing tri-axial ellipsoid dimensions. Michaelbusch 16:03, 17 August 2006 (UTC)[reply]

Physical Characteristics[edit]

Next to "Mean surface temperature", on the Physical Characteristics table, the min and max temperatures are given, the temperature Extremes for "4 Vesta", but not the actual "Mean surface temperature" for the asteroid. Obviously, the mean is easy to calculate, even for my little brain, from the min and max data but still there is an inconsistency in this table. Actually, I find the min max temperature more interesting data than just the mean by itself.

We cannot specify a mean temperature by taking the average of min and max, because we don't know the distribution of temperature across the surface of the asteroid. Even the min and max are uncertain, particularly the minimum (because we have little data on the nightside). We can calculate an average temperature for the surface by taking the albedo and average cross-section, using those to compute the total solar energy incident, then dividing that by the effective surface area of the object to get the mean power radiated per unit area. However, this is not the same as a geometric mean across the surface. Michaelbusch 16:03, 17 August 2006 (UTC)[reply]

Fragments[edit]

Could someone elaborate on how we know the meteorites originated on Vesta, and not some other asteroid? Gary 04:51, 20 August 2006 (UTC)[reply]

The spectra of the V-type asteroids, as well as the HED meteorites, match Vesta's very distinctive spectrum. The meteorites probably didn't come directly from Vesta, but we can assume that they have been through a similar history (see the physical properties section) Michaelbusch 16:20, 20 August 2006 (UTC)[reply]

  • it is the same process as we know ALH84001 is from Mars. I just read about Vesta and those meteorites probably did originate in Vesta, Vesta was hit by a massive impact which destroyed part of it (that is why it is "half round, half not"). Vesta remains even reached Earth! So Vesta and Ceres are seen by leading planetologists as mini-planets and protoplanets, not as asteroids.-Pedro 22:25, 7 September 2006 (UTC)[reply]

In addition the debris form 4 Vesta's great polar crater should be a rich source of terrestrial meteorites, "about 5 percent of all meteorites we find on Earth are a result of this [Vesta's polar crater] single ancient crash in deep space."[2] Pulu (talk) 23:38, 29 July 2011 (UTC)[reply]

GA[edit]

Good article, keep up the good work -- Nbound 00:54, 17 September 2006 (UTC)[reply]

Symbols[edit]

I've added a little more information, but I'm not sure where to link for MPC numbers. Please help! Adam Cuerden talk 23:52, 4 October 2006 (UTC)[reply]

...Weel, it was deleted. Still, it WAS accurate and cited, (and involved a fair bit of work to make the new symbol) so I paste the cut text here if anyone sees a better way to work it in. It starts just after the opening as it stands now.

When designated by a symbol it is usually , but it is sometimes Old symbol of Vesta or Old planetary symbol of Vesta. All are simplifications of the original rather more detailed hearth, . The difficulty of drawing the symbols for the asteroids from Vesta onwards led to B. A. Gould suggesting a numbers in circles to be used instead, which would eventually simplify to the number in parentheses: (4) Vesta, and then finally to just the number: 4 Vesta - in short, the MPC number system used for all minor planets today. [3])
I thought it was fascinating. I'm not sure why it needed to go. --Aranae 02:27, 5 October 2006 (UTC)[reply]
My rational for the original deletion of the more detailed description of the history of the symbols was twofold: one that it was uncited (this has been fixed) and two that, while it is interesting, it was somewhat long and does not relate to the remainder of the article (because symbols are very rarely used, and almost never for asteroids). It might be appropriate in one of the articles dealing with the history of astronomical terminology. If there is consensus for keeping the material, let it be decided here. Michaelbusch 02:32, 5 October 2006 (UTC)[reply]
The only reason why I added the symbols to the body of the article was because I reduced the symbols at the top of the infobox down to just one, and some people complained about the same thing being done on 1 Ceres. Not only are asteroid symbols virtually unused in the astronomical world, but the astrological world pretty much only uses the one in the infobox. I'd cut it right down to "When designated by a symbol it is usually " if there weren't objections. └ OzLawyer / talk ┐ 03:08, 5 October 2006 (UTC)[reply]
Er... actually, that cite was there from the start. Still, the main body of information probably ought to go in an article on Minor Planet Number - who wants to join me in writing one? Adam Cuerden talk 06:45, 5 October 2006 (UTC)[reply]
Er...actually, it wasn't. └ OzLawyer / talk ┐ 12:36, 5 October 2006 (UTC)[reply]
It was, at least from when I added the controversial part. Not that it matters that much.
Yes, clearly it was there when you added to it. My point was that if I hadn't added it in the first place, the article might have continued without any discussion about the symbol, which I actually think is better. At the most, it needs just a note that the symbol at the top of the infobox is the most common of several symbols for the asteroid. └ OzLawyer / talk ┐ 14:21, 5 October 2006 (UTC)[reply]

Sorry about that, got confused and was sttressing out a bit over an oral report at the time. Adam Cuerden talk 18:11, 5 October 2006 (UTC)[reply]

---

A note for the record: from what I can tell, the simple square with Aries-horns was Gauss's original design. Some contemporaries made more elaborate drawings of the actual altar in Rome. The other simple version seems to be from a woodcut in Koch (1930). So this isn't a matter of complex to simple. (There were similar complex variants of Juno and other asteroids, but no one bothered to upload them to WP.) And the modern symbol was created for astrology in the 1970s. — kwami (talk) 08:11, 10 November 2021 (UTC)[reply]

Largest asteroid[edit]

According to http://www.iau2006.org/mirror/www.iau.org/iau0603/iau0603_Q_A2.html , Ceres is no longer an asteroid. 132.205.44.128 05:15, 13 November 2006 (UTC)[reply]

I was the one who originally posted that reference... please see my reply to your post here. Thanks! --Ckatzchatspy 05:59, 13 November 2006 (UTC)[reply]

You can also see Talk Ceres and Talk kheider. I believe that Ceres is still an asteroid until an official statement is released. A poorly worded press release is not very reliable. Vesta may be a Dwarf Planet Remnant, and thus may not be an asteroid *IF* (1) the rule: "Once a dwarf planet, always a dwarf planet" is applied and (2) Dwarf Planets are not asteroids. -- Kheider 15:06, 13 November 2006 (UTC)[reply]

Sorry if my post wasn't clear... my link to "here" points to the discussion at Talk Ceres as well, since 132.205.44.128 posted a similar question there. --Ckatzchatspy 20:01, 13 November 2006 (UTC)[reply]

Actually that points to Talk Asteroid. So yes, the conversation is in multiple locations. :-) -- Kheider 19:36, 14 November 2006 (UTC)[reply]

Yes, well, I learned to read at a very early age, before all this new-fangled A-B-C stuff came about... 8) --Ckatzchatspy 21:32, 14 November 2006 (UTC)[reply]

Color image[edit]

A color image of Vesta is available:

http://hubblesite.org/newscenter/archive/releases/2007/27/image/c/

— RJH (talk) 21:37, 20 June 2007 (UTC)[reply]

As a Hubble image it's not PD. Is there a fair use rationale that applies? Lexicon (talk) 22:34, 20 June 2007 (UTC)[reply]
Please see http://hubblesite.org/copyright/ for Copyright information regarding hubble pics. Accroding to their copyright notice, this one is PD or FUR. Abyssoft 11:44, 21 June 2007 (UTC)[reply]

Occasionally Ceres can come closer to the Sun than Vesta[edit]

You can not allows easily diagram 3 dimensional space on a 2 dimensional drawing.

  • For example look at the JPL orbital simulation for 887 Alinda. When you first load it, it looks like 887 Alinda crosses the orbit of Earth. But if you drag the bar on the right to the bottom, you will see that this asteroid does not cross Earth's orbit. Since it has a perihelion (closest distance to the Sun) of 1.07AU it does stay outside of the Earth's orbit.
  • Another good example is Pluto. If you load the JPL orbital simulation for Pluto, zoom in some, and rotate to the left you can make it appear as if Pluto always stays further from the Sun than Neptune.
  • If you look at JPL's 2-body orbital simulation for Ceres and Vesta and move forward to 2009-02-10, you will see that Ceres is closer to the Sun at that time. Vesta 2.56AU; Ceres 2.54AU. -- Kheider (talk) 17:03, 31 May 2008 (UTC)[reply]

mass[edit]

A hidden comment showed the mass as having 4 sig figs, so I changed the info box to match. However, I don't have access to the article. 4 seems awfully precise. Can someone confirm the error? Even in the abstract it's clear that there's at least 3 sig figs, and we only had two. kwami (talk) 14:37, 4 November 2008 (UTC)[reply]

The mass of Vesta as listed in Pitjeva, 2005 is 1.344 ± 0.001 × 10−10 mass of Sun. Ruslik (talk) 15:11, 4 November 2008 (UTC)[reply]
Good, thanks. Just wanted to check. kwami (talk) 15:20, 4 November 2008 (UTC)[reply]

Actually the masses of the major asteroids are still poorly known. A lot of it depends on the true mass of Ceres and Pallas. Of the large asteroids, Vesta appears to have the best known mass. Some non-PDF reading: Asteroid Masses and Densities, Hilton (Masses of the Largest Asteroids), New determination of the mass of Pallas -- Kheider (talk) 15:38, 4 November 2008 (UTC)[reply]

GA Reassessment[edit]

This discussion is transcluded from Talk:4 Vesta/GA1. The edit link for this section can be used to add comments to the reassessment.

This article has been reviewed as part of Wikipedia:WikiProject Good articles/Project quality task force in an effort to ensure all listed Good articles continue to meet the Good article criteria.

Overall, this article is very well-written and, for the most part, well-referenced. Comprehensiveness, neutrality, stability, and images are all fine. A few concerns came up during my review:

  1. One or both of the lists in the "Geology" section may work better as prose.
    I think some sort of geometrically sequential arrangement is appropriate, as both indicate sequences. I think prose would be much harder to follow, especially for someone trying to skim the article. However, I do agree that the list format is not the greatest for legibility. I've converted to tables. They may need some adjustment, but see what you think. kwami (talk)
  2. The last paragraph of the "Geology" section (the thickness of the crust) should be referenced.
    done Nergaal (talk) 00:28, 16 November 2008 (UTC)[reply]
  3. Near the end of the second paragraph in the "Surface features" section, a reference is placed directly after "Hubble images". References should normally be placed after punctuation to make it clear what they are referencing. Does this cover the information before the reference, after the reference, or both?
    "Interestingly Vesta was not disrupted nor resurfaced by an impact of this magnitude." is a non-sequitour. Nergaal (talk) 00:28, 16 November 2008 (UTC)[reply]
  4. Likewise, in the final paragraph of that section, does the reference cover the entire paragraph?
  5. The "Exploration" section should be referenced.
  6. In the "Exploration" section, Dawn is italicized the first time but not in subsequent mentions. Is there a reason for this?
    Nope. All now cap'd. kwami (talk) 19:07, 5 November 2008 (UTC)[reply]
  7. Can more information be provided for Reference 26?
    Done. kwami (talk) 09:30, 6 November 2008 (UTC)[reply]

I will place this on hold for a week to allow for these concerns to be addressed and/or discussed. If progress is being made, an extension will be granted if necessary. Any questions and/or comments can be left here, as I have placed this page on my watchlist. Best wishes, GaryColemanFan (talk) 18:32, 5 November 2008 (UTC)[reply]

Interesting note: While looking for sources for the "Exploration" section, I came across this article published by Reuters. Facts #2 and 3 looked familiar, so I checked an old revision of Wikipedia's 4 Vesta article (http://en.wikipedia.org/w/index.php?title=4_Vesta&oldid=160069737, last edited three days before the Reuters article). It turns out that Reuters copied them and pasted them directly from here. GaryColemanFan (talk) 03:39, 9 November 2008 (UTC)[reply]

Thanks for warning me about the possible de-listing GaryColemanFan, I've been busy with other projects off of Wikipedia. I'll get right to assisting with the assessment. --IdLoveOne (talk) 23:29, 20 November 2008 (UTC)[reply]

In Favor per Wikipedia:Reviewing good articles:

  • The article is NPOV
  • No cleanup requested
  • No edit wars appear to be going on
  • I observe no grammatical errors
  • Clearly written and broad in coverage in regards to the topic
  • All images tagged and licensed and usage is allowed

However I'm not sure what wiki's standard is about it being "current" but obviously the Dawn mission justifies that a bit, and I don't know if all the links are reliable, can someone else check this or tell me how to do it?--IdLoveOne (talk) 03:10, 21 November 2008 (UTC)[reply]

I will try to fix remaining issues today. Ruslik (talk) 04:35, 21 November 2008 (UTC)[reply]
Fixed 4 and 5. Ruslik (talk) 08:44, 21 November 2008 (UTC)[reply]
I've cleaned up the references (yet again), and addressed the remaining points. Looks good to me now. Urhixidur (talk) 15:50, 21 November 2008 (UTC)[reply]

Q. Is the following paragraph really needed in an article about Vesta?

NASA attempted to cancel Dawn in 2006, citing budget pressures and technical issues, but scientists appealed and won an additional $100 million to continue the program. Total mission costs will now be about $450 million.

Thanks.—RJH (talk) 16:13, 21 November 2008 (UTC)[reply]

In response to RJH, the total cost of the mission doesn't seem particularly important. Since there was no soucred provided, I removed that sentence and combined the final two paragraphs.

All of my concerns have now been addressed, so I am going to close this reassessment and keep this article listed as a GA. Thanks you to everyone who helped, GaryColemanFan (talk) 18:30, 21 November 2008 (UTC)[reply]

Thanks. Good job!—RJH (talk) 18:49, 21 November 2008 (UTC)[reply]

Good, but what about Pallas, Hygiea and Juno? --IdLoveOne (talk) 21:52, 22 November 2008 (UTC)[reply]

I have already performed recent GA reassessments of Pallas and Juno, and both articles retained their GA status. Because Hygiea was listed as a GA after August 2007, it is not included in the first round of GA sweeps. GaryColemanFan (talk) 22:17, 22 November 2008 (UTC)[reply]

error ranges[edit]

Can s.o. add the error estimates for the diameters? I don't have access to the ref. Even with the PD error bars for Pallas it's clear the two overlap, but it would be nice to be accurate rather than just precise. kwami (talk) 01:20, 18 November 2009 (UTC)[reply]

You could also use either Baer2008 ==> Baer, James (2008). "Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris" (PDF). Celestial Mechanics and Dynamical Astronomy. 100 (2008). Springer Science+Business Media B.V. 2007: 27–42. doi:10.1007/s10569-007-9103-8. Retrieved 2008-11-11. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help) OR Baer2009 ==> Jim Baer (2009). "Recent Asteroid Mass Determinations". Personal Website. Retrieved 2008-12-06. The Hubble reference is from 1997. -- Kheider (talk) 02:47, 18 November 2009 (UTC)[reply]

the time of less favorable oppositions[edit]

The synodic period of 4 Vesta is about 1.38 years. So for an opposition on a particular date, the 3rd, 5th and 8th following oppositions will be at close to the same calendar date. The less favorable oppositions that were tagged with a when template and "What year?" comment recur whenever the opposition happens in late autumn. With my calculator I get oppositions near Nov. 18th on 2012, 2016, 2019 and 2023. A planetarium program could give exact dates. I am not sure what is best to put into the article. --Fartherred (talk) 04:46, 17 October 2010 (UTC)[reply]

With Horizons I get: (Date, Distance, Sun-Earth-Vesta angle)
2012-Dec-07 1.589AU 173.96°
2017-Jan-18 1.522AU 177.13°
2019-Nov-13 1.565AU 170.49°
-- Kheider (talk) 07:17, 17 October 2010 (UTC)[reply]

Interior of Vesta[edit]

There is a good article at the Max Planck Society discussing some new findings about the interior of Vesta. Link The original article is from Icarus through Elsevier and is located here. --Xession (talk) 04:26, 7 January 2011 (UTC)[reply]


Only remnant protoplanet[edit]

Claiming 4 Vesta is the ONLY remnant protoplanet is a bad idea in IMHO. The Kuiper belt likely has many such objects. 4 Vesta may be the only remnant protoplanet in the asteroid belt, but I also think Ceres and 2 Pallas can claim to be protoplanets. -- Kheider (talk) 18:20, 7 January 2011 (UTC)[reply]

The physorg.com article cites Reddy et al. (2010). Perhaps somebody could check there to see what they really stated? I don't have access to Icarus.—RJH (talk) 18:52, 7 January 2011 (UTC)[reply]
The Max Planck Society article used as reference (#11 MAX) does list Dr. Andreas Nathues (one of the authors) as a contact so I trust it more than physorg. But like yourself, I do not have access to Icarus. -- Kheider (talk) 20:04, 7 January 2011 (UTC)[reply]

All three big asteroids have been called "protoplanets". And Vesta but not Ceres?

Under the heading "Discovery" is the statement "Ceres, Pallas, and Vesta are not fragments of a larger body", which is unsupported by data. Should this be labelled "speculation", or "conjecture", or some such? — Preceding unsigned comment added by 67.233.251.196 (talk) 07:19, 23 September 2012 (UTC)[reply]
Given that Vesta is partially differentiated and Ceres (being spherical) is in hydrostatic equilibrium, what larger body do you speculate they are from? Due to Jupiter being the 1st planet to form, Ceres+Vesta+Pallas were all prevented from further accretion by Jupiters gravitational scattering of other objects. -- Kheider (talk) 16:01, 23 September 2012 (UTC)[reply]
We have several sources stating that explicitly, though I don't recall which ones. — kwami (talk) 23:54, 23 September 2012 (UTC)[reply]

Season at DAWN?[edit]

What will the vestan season be when DAWN arrives? The visit will be only 0.2 vestan years, so there won't be a lot of change if one hemisphere is in winter. — kwami (talk) 14:27, 7 February 2011 (UTC)[reply]

Vesta doesn't have a significant atmosphere, so I'm not sure what type of change you are expecting. Please could you clarify?—RJH (talk) 16:42, 7 February 2011 (UTC)[reply]
The season could affect which areas of Vesta are illuminated or not while Dawn is in orbit. --Patteroast (talk) 17:44, 7 February 2011 (UTC)[reply]
That's true. Thanks.—RJH (talk) 19:39, 7 February 2011 (UTC)[reply]
Yes, that's what I was wondering: how much of Vesta will we actually see? Will the southern crater be visible? What about the expected compression fractures at its antipodes? — kwami (talk) 21:03, 7 February 2011 (UTC)[reply]
I can't seem to find the paper discussing the Framing camera in short order, but it is capable of imaging in the near-IR (see here). There is also a visible/infrared spectrometer that will provide colorful maps many will be familiar with from recent missions to the Moon. The mission won't likely leave much, if any, of the surface on either Vesta or Ceres unmapped. --Xession (talk) 21:12, 7 February 2011 (UTC)[reply]
Yeah! Southern summer! Just heard back from NASA. No citable source, so I hope you don't mind me just adding it to the article. — kwami (talk) 20:11, 10 March 2011 (UTC)[reply]

Dead link[edit]

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Dead link 2[edit]

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Dead link 3[edit]

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puzzled[edit]

I'm puzzled. In the image from July 17,

,

the southern hemisphere is half in shadow. But on July 9,

,

it was fully illuminated. Vestian seasons don't change in a week, and rotation shouldn't make any difference, so what's going on? Or is that not the southern crater that we're seeing? — kwami (talk) 22:36, 18 July 2011 (UTC)[reply]

The Dawn spacecraft, which took both images, was still en route to Vesta on July 9, but is now orbiting around it. The movement of the spacecraft itself is what caused the shadow change. LittleMountain5 22:44, 18 July 2011 (UTC)[reply]
Thanks, but I don't understand. The position of Dawn should have no impact on which areas of Vesta are illuminated. — kwami (talk) 22:50, 18 July 2011 (UTC)[reply]
Oh, I see. I'm not entirely sure why the the illumination of certain areas on Vesta have changed... probably due to its quick rotation (about five hours) and axial tilt (about 29 degrees). I'm no expert, though. LittleMountain5 22:57, 18 July 2011 (UTC)[reply]
Yeah, but AFAIK that peak is at the south pole. Axial tilt would matter, but only on the scale of years as southern winter approaches. Over the course of a day the terminator would rotate around the world, but it shouldn't approach or recede from the pole. Unless what we're seeing is not the southern hemisphere, but then I have no idea where we are on Vesta: Do we have a second global-scale crater on Vesta? — kwami (talk) 23:01, 18 July 2011 (UTC)[reply]
As far as I can tell from comparing the two images, we are indeed looking at the same massive crater on Vesta's southern hemisphere. (Notice the three smaller simple craters on the upper middle of the newer image and the lower left of the older image.) The giant crater isn't exactly centered on the south pole (see this image), so maybe that accounts for the deviation? LittleMountain5 23:16, 18 July 2011 (UTC)[reply]
If you rotate the July 11 image by about 130 degrees clockwise, you can see that the smaller craters line up with the July 17 image. Fromthe shadows in those craters, you can then see that the Sun has changed position by nearly 180 degrees. So I think that big mound in the middle of July 17 is near the equator. That's gotta be one huge peak, from the floor. Tbayboy (talk) 23:08, 18 July 2011 (UTC)[reply]
Actually, playing with the images, it's more like 150 degree image rotate, to get maybe 120 degrees change in Sun angle. So the craters along the lip of the crentral mound look like mid-latitude, so the crater itself looks like it encompasses a pole. From this angle, Vesta really pushes the question of "how round is round?". Tbayboy (talk) 23:31, 18 July 2011 (UTC)[reply]
So we have a polar crater, but with a mid-latitude peak within it? Is there maybe an outer wall that encompasses more than the flat spot at the pole? Reconstructions from Hubble show a polar peak as well. I guess I'll have to see the thing mapped. — kwami (talk) 23:38, 18 July 2011 (UTC)[reply]

This image is captioned as centered at 55°S. The mountain isn't in the center of the image, though. But this sure does look like the peak seen in Hubble images. I'd just always assumed that was at the pole due to angular-momentum constraints. — kwami (talk) 01:12, 19 July 2011 (UTC)[reply]

They're fascinating images. What seems curious to me is that the surface is not fully saturated with crater impacts. All of the impacts I can see look fairly fresh (non-worn). It appears as if the asteroid has been significantly resurfaced with what appears to be an ejecta blanket (or some other process). But that's just my non-expert speculation. It'll be interesting to get a good look at the south pole impact site. Regards, RJH (talk) 15:18, 19 July 2011 (UTC)[reply]
The polar impact is thought to have been less than a billion years ago. That would have resurfaced the entire world.
And evidently NASA will extend the mission until they can get a good look at the north pole too, for the expected compression fractures. — kwami (talk) 18:48, 19 July 2011 (UTC)[reply]

Dawn quibble[edit]

"After orbiting Vesta for approximately one year, in July 2012 Dawn will proceed to its other target, Ceres. This is possible, as the spacecraft is the first that can enter orbit around more than one body as a result of its weight-efficient ion-driven engines.[45]"

Is this the main reason actually the engines, or is it at least as much that the very low gravity enables the craft to escape orbit so much more easily than from say a planet? 109.153.234.156 (talk) 23:23, 18 July 2011 (UTC)[reply]

The engines. Dawn could escape from a planet too, it would just take longer (and more fuel). But AFAIK a traditional rocket would be incapable of doing what's planned for Dawn. That's what got this thing funded: no-one cared enough about asteroids to actually fund a mission, but they would fund an asteroid mission in order to demonstrate the abilities of the ion drive. — kwami (talk) 23:40, 18 July 2011 (UTC)[reply]
Oh OK, thanks for confirming it. 109.153.234.156 (talk) 23:59, 18 July 2011 (UTC)[reply]
Yeah, Dawn's accelerated more under those engines than any rocket ever has. And it's not done yet. I just hope there's enough fuel left to break Cererian orbit and make a flyby of Pallas. — kwami (talk) 01:21, 19 July 2011 (UTC)[reply]

rotation clip[edit]

does anyone have access to the rotation clip they showed today? That would be an awesome header image, like we have for Pluto.— Preceding unsigned comment added by Kwamikagami (talk • contribs) 00:36, 2 August 2011 (UTC)[reply]

You can download it here, but I don't know how to convert it to OGG, the required video file type. LittleMountain5 00:59, 2 August 2011 (UTC)[reply]
I can convert to ogg, but not with the codex they want, because firefog is not compatible w v. 5. I'll ask for help. — kwami (talk) 01:46, 2 August 2011 (UTC)[reply]
I also figured out how to convert it to OGG (with the correct codex), but upon looking at Pluto's example again, I realized it's an animated GIF. Making something like that would require either finding each separate image NASA used in their video, or taking frames from the video itself. I'll try to work on it tomorrow. LittleMountain5 02:31, 2 August 2011 (UTC)[reply]
The high-def version really makes a big difference, but I don't know how practical it would be. — kwami (talk) 04:32, 2 August 2011 (UTC)[reply]
I tackled the harder one first: here's the animated GIF. Note that this is the first time I've ever made an animated GIF, so suggestions for improvement are welcome. Cheers, LittleMountain5 00:54, 3 August 2011 (UTC)[reply]
Beautiful! It's large, but even with a slow connection it will display a perfectly good image while it continues to download. — kwami (talk) 01:04, 3 August 2011 (UTC)[reply]
Yeah, I tried to make it as big as possible to preserve at least some of the detail. Do you think it's a good speed? I animated a little faster than the video so it rotated more smoothly, but now I'm second guessing myself. LittleMountain5 01:08, 3 August 2011 (UTC)[reply]
The speed is fine. It's going to be much slower anyway as it loads. I was hoping for full res, but see now that that would be unmanageably large, and the detail is pretty good as you have it. — kwami (talk) 01:40, 3 August 2011 (UTC)[reply]

Provisional map, though only ±30°, so I don't know if it's worth uploading. — kwami (talk) 05:21, 2 August 2011 (UTC)[reply]

This is now officially the coolest infobox photo of all articles in all Wikipedias.--Cam (talk) 15:11, 6 August 2011 (UTC)[reply]

What happened to the rotating clip in the infobox? Was there a reason for its removal? I thought it looked fantastic the way it was - I think an animated picture conveys a lot more information than a still photograph. Danskheart (talk) 21:20, 23 December 2011 (UTC)[reply]

I liked it too. S.o. thought it took too long to load, tho while it was loading you still had a still to look at. — kwami (talk) 21:28, 23 December 2011 (UTC)[reply]
Is the current still of better quality than the loading rotation clip? If not I would move that we re-introduce the rotation clip. I'll defer to your judgement though (My internet connection may make my opinion a bit biased) - Danskheart (talk) 21:33, 23 December 2011 (UTC)[reply]

Name explain - Why 4?[edit]

A casual reader should be offered an immediate answer to the obvious question, What does the 4 in the name mean? A reader with more interest should be offered a detailed history of the name, and particularly when the modern name was first used, and when the modern form became the dominant form of reference.-96.237.15.189 (talk) 12:28, 2 August 2011 (UTC)[reply]

By 1851 there were 15 known asteroids, all but one with their own symbol. The symbols grew increasingly complex as the number of objects grew, and, as they had to be drawn by hand, astronomers found some of them difficult. This difficulty was addressed by Benjamin Apthorp Gould in 1851, who suggested numbering asteroids in their order of discovery, and placing this number in a circle as the symbol for the asteroid, such as ④ for the fourth asteroid, Vesta. This practice was soon coupled with the name itself into an official number-name designation, "④ Vesta", as the number of minor planets increased. By ca 1858, the circle had been simplified to parentheses, "(4)" and "(4) Vesta", which was easier to typeset. Other punctuation such as "4) Vesta" and "4, Vesta" was also used, but had more or less completely died out by 1949.[1]

So. I put the explanation and history of the name in the article. 3 hours later, someone took it out. Brillant. I won't edit war. The next move is yours.-96.237.15.189 (talk) 23:53, 2 August 2011 (UTC)[reply]

The explanation is linked at the very top of the article, with the appearance of the designation, and I made the link a little "bigger" because it is a good question. The explanation is not distinct to Vesta, but is common to all minor planets, and so belongs in its own page, where it already was (and where it was copied from). It's silly to repeat the same thing over and over again in all pages for minor planets, or to single out Vesta for special treatment. Tbayboy (talk) 01:49, 3 August 2011 (UTC)[reply]
We single out Vesta for special treatment because it is special: it's in the news because of Dawn. A lot of people will come here who wouldn't normally visit asteroid articles, including a lot of kids, and they're not going to know what a "MPC designation" is, link or no link. We should say something. — kwami (talk) 09:14, 5 August 2011 (UTC)[reply]
I agree, this is no longer just any asteroid article. Vesta is in the news media a couple of times a week now, and will get periods of intense media coverage over the next year. It is therefore in line with Wikipedia's public education / encyclopedic mission to add more detailed explanations.
Writeonandon (talk) 12:56, 5 August 2011 (UTC)[reply]

"The explanation is not distinct to Vesta."

But, the explanation IS distinct to Vesta! Which is why it belongs here in perpetuity, regardless of whether other articles retain similiar material now or in the future. It is appropriate for both of these articles to have this material, but over time the other article may use entirely different examples.-96.237.15.189 (talk) 13:37, 8 August 2011 (UTC)[reply]

References

  1. ^ From Dr. James Hilton's When Did the Asteroids Become Minor Planets?, particularly the discussion of Gould, B. A. 1852, On the Symbolic Notation of the Asteroids, Astronomical Journal, Vol. 2, and immediately subsequent history. The discussion of C. J. Cunningham (1988), also from there, explains the parenthetical part.

Since the article is supposed to be easily read by lay persons and the well known name of Vesta is "Vesta", not the technical name "4 Vesta", I don't understand why the article appears under the name "4 Vesta" or why this planetoid is called "4 Vesta" in some other articles (e.g., HED meteorite). I wonder if even astronomers in research papers consistently call it "4 Vesta". I propose moving this page to "Vesta" with (of course) a redirect from "4 Vesta", having the technical name "4 Vesta" only mentioned in this and other articles, not used every time. I argue for this based on the analogy with the "Samuel Langhorne Clemens" article (there is none; it's a redirect to Mark Twain) and many similar cases. Zaslav (talk) 02:21, 27 April 2016 (UTC)[reply]

The thing is is that there is also Vesta (mythology). This means that just "Vesta" is ambiguous. To indicate that this article is about the minor-planet, the "4" is prepended. The article title could also have been "Vesta (minor planet)" or "Vesta (asteroid)", but natural disambiguation, i.e. disambiguation without parentheses, is preferred, hence the title "4 Vesta". --JorisvS (talk) 09:50, 27 April 2016 (UTC)[reply]
Thank you. I see that Vesta is a disambig page. It makes sense now. However, I think the incessant mentions of "4 Vesta" in HED meteorite should be simplified. Zaslav (talk) 02:28, 30 April 2016 (UTC)[reply]

Is or Isn't Vesta the Number Two Largest Asteroid?[edit]

After seeing the original claim that Vesta is "the second largest asteroid" edited out in one spot, (but not all spots), along with an authoritative-looking note that Vesta is yet to be clearly determined to be either the 2nd or 3rd largest asteroid, I removed the (remaining) fragments also stating that is was "2nd largest", since this no longer appeared to be confirmed.

But my edits were then reverted, and now I am confused.

It looks like the "2nd place in size" status is being removed in some areas-- but left in place (and defended) in other areas, which is inconsistent.

Can we get a resolution on what to do here, so the article can be kept factually consistent?

(See also reference to "Ceres" in article opening that still mentions Vesta as being the "2nd largest asteroid").

Thanks,

Writeonandon (talk) 17:01, 5 August 2011 (UTC)[reply]

The situation is explained in the first paragraph of the Physical characteristics section. --JorisvS (talk) 17:21, 5 August 2011 (UTC)[reply]
Thanks for the link! OK I can see now, it's confirmed number 2 in mass, but not yet confirmed in size, due to density differences that may give Pallas the edge in total size, or volume.
Writeonandon (talk) 17:40, 5 August 2011 (UTC)[reply]

Dimensions[edit]

The currently stated dimensions of Vesta are from 14 years ago. Wouldn't the dimensions be known far more accurately now that Dawn is orbit around Vesta? --JorisvS (talk) 22:53, 7 August 2011 (UTC)[reply]

I added a note to the intro. We're basically waiting for the new data to be published.--agr (talk) 12:22, 8 August 2011 (UTC)[reply]

Southern crater[edit]

Does the huge impact basin near Vesta's south pole have a name? --JorisvS (talk) 15:22, 9 August 2011 (UTC)[reply]

Yes. It is called the "Huge Impact Basin". 107.29.180.162 (talk) 20:41, 9 August 2011 (UTC)[reply]
Not much of a name, is it? Think you could reference that? --JorisvS (talk) 20:53, 9 August 2011 (UTC)[reply]
Vesta's Hearth? Cheers, Greenodd (talk) 23:42, 9 August 2011 (UTC)[reply]
Maybe "Ouch!". — kwami (talk) 00:22, 10 August 2011 (UTC)[reply]
I like that one... the Ouch! Crater.:D Funny, but, seriously for one moment; so, can I conclude from the tone here that it still simply doesn't have one? --JorisvS (talk) 11:05, 10 August 2011 (UTC)[reply]
AFAIK, the only named Vestian feature is Olbers, and no-one knows what that is, because it's only visible in Hubble images. (Some large albedo feature that disappears when you get close up.) There are informal names like the 'snowman', and maybe the southern crater has one like that, but it's probably just 'southern crater'. I'm sure people are pondering what an appropriate name would be (Olbers would have been the obvious choice, like Herschel on Mimas), and for the central peak as well, but we don't even have the new mass measurements yet. — kwami (talk) 11:21, 10 August 2011 (UTC)[reply]
Yes. Any idea when we could expect elementary info like mass and dimensions to be published? --JorisvS (talk) 11:56, 10 August 2011 (UTC)[reply]

And why are we not getting any true-color shots? — kwami (talk) 11:30, 10 August 2011 (UTC)[reply]

Maybe because at NASA they think that true-color images are not really interesting? --JorisvS (talk) 11:56, 10 August 2011 (UTC)[reply]
From the rumours I've heard it's quite the opposite, but the Dawn team's data-release policy has come under some stick from enthusiasts for being relatively glacial. Do not expect anything more than a trickle of info. As for surface feature names, the team will eventually be required to present a surface map with suggested names to the IAU for example like was done with Lutetia [4]. ChiZeroOne (talk) 13:25, 10 August 2011 (UTC)[reply]
Here is 21 Lutetia's Wikilink in case anyone is interested.
69.171.160.5 (talk) 11:19, 13 August 2011 (UTC)[reply]

Rheasilvia.[5][6] --JorisvS (talk) 19:32, 5 October 2011 (UTC)[reply]

Duplicate image of Vesta tagged for transfer to Commons[edit]

The file Vesta from 265000 km cropped 260.jpg, has been flagged for tranfer to Commons by Svenbot. The same image, slightly differently cropped, already exists there (File:Vesta image by Dawn probe.jpg). So I'd say it can simply be deleted. The uncropped version (File:Vesta from 265000 km.jpg) does not exist on Commons and has also be flagged. I don't see how an uncropped version could have any added value, but if someone disagrees... . --JorisvS (talk) 17:01, 28 August 2011 (UTC)[reply]

Claudia[edit]

Reference to http://www.nasa.gov/mission_pages/dawn/multimedia/pia14715.html or similar is needed. 94.30.84.71 (talk) 12:30, 30 September 2011 (UTC)[reply]

Iron core[edit]

Vesta has an iron core. -- Kheider (talk) 16:09, 3 October 2011 (UTC)[reply]


That sounds like planetary dynamics to me. I don't think most asteroids have iron cores. Maybe a new category will be needed for Vesta, not quite a dwarf planet, but not just a big space rock either. Have any citations along these lines emerged?

69.171.160.247 (talk) 21:29, 17 October 2011 (UTC)[reply]

Surface features names[edit]

I think this page needs a link to a new page listing the recently announced names of surface features on Vesta. I haven't had a chance to check all of them myself, but the craters seem to be named after well-known Roman families.

http://planetarynames.wr.usgs.gov/SearchResults?target=VESTA — Preceding unsigned comment added by 218.214.138.229 (talk) 05:34, 5 October 2011 (UTC)[reply]

Almost, but not quite. Surface features are/are to be named after Roman Vestal Virgins.Catiline63 (talk) 13:03, 13 October 2011 (UTC)[reply]

Pickering[edit]

In Early measurements, it's said: «William H. Pickering produced an estimated diameter of 513 ± 17 km in 1879, etc.», reporting as source Hughes, D. W (1994). How did you identified which Pickering brother made the measurments? As Hughes reports as source an article of Edward Charles Pickering (Pickering, E. C., 1879, Annals Astron. Obs. Harvard, 11, part 2, p. 291), the identification may be wrong. --Harlock81 (talk) 08:54, 6 October 2011 (UTC)[reply]


Just pick a Pickering and you'll be fine. Neither will be picky about it.

69.171.160.247 (talk) 21:35, 17 October 2011 (UTC)[reply]

I verified that Hughes cites E.C. Pickering and changed it in our article.--Cam (talk) 02:43, 17 November 2011 (UTC)[reply]
Bibcode for the Pickering paper is 1879AnHar..11..191P. I am not bold enough to attempt to construct the reference for that.--Cam (talk) 02:56, 17 November 2011 (UTC)[reply]
Thanks! p. 294. --Harlock81 (talk) 17:18, 14 December 2011 (UTC)[reply]

Northern pole[edit]

I was wondering about Vesta's northern polar region in this animation. Is the flattening here real or just not included because that part has not been mapped (yet)? Hubble images do not show such flattening. --JorisvS (talk) 21:15, 23 November 2011 (UTC)[reply]

The north polar region has not been mapped yet as it is in darkness, IIRC it won't be able to be mapped until nearer the end of Dawn's time at Vesta. ChiZeroOne (talk) 21:30, 23 November 2011 (UTC)[reply]
Yes, I suspected that already. Thanks for confirming. --JorisvS (talk) 21:37, 23 November 2011 (UTC)[reply]

Yes, the animation just cuts off. Per P.C., Dawn's mission is being timed to enable full coverage of the north pole. The original schedule would have had Dawn leaving prior to that. — kwami (talk) 00:06, 29 November 2011 (UTC)[reply]

File:Vesta and some other asteroids.jpg Nominated for speedy Deletion[edit]

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Outdated[edit]

Vesta has been recently determined to be a dwarf planet, not an asteroid. --76.180.168.219 (talk) 20:28, 7 December 2011 (UTC)[reply]

Citation please. Also, being a dwarf planet doesn't mean it isn't an asteroid: Ceres is still an asteroid. --JorisvS (talk) 23:34, 7 December 2011 (UTC)[reply]
Also be careful confusing a protoplanet with a dwarf planet. -- Kheider (talk) 23:45, 7 December 2011 (UTC)[reply]

OK So is it a Planet or Not?[edit]

I saw on one of the science channels today that the lead scientist studying Vesta for NASA (as well as a number of his research team members) now believe that Vesta meets the requirements to be classified as a "dwarf planet". Yet I have also seen it listed in many places as an asteroid.

It seems that if there is credible mainstream scientific discussion about listing Vesta as a dwarf planet that this deserves a section in the article. Not a section that says that Vesta is one, but that reassigning it's status is being recommended by key researchers in the scientific mainstream. Such a debate is worthy of an article mention, although I doubt the issue will be settled for some time. The same science report today did quote other scientists who do not agree that Vesta is a dwarf planet, but believe instead that it is a "proto-planet" (stillborn embryonic planet, so to speak). 64.134.152.48 (talk) 00:30, 15 December 2011 (UTC)[reply]

Great! Please provide a ref, so we have s.t. to go on.
Vesta would still not be a planet, though. — kwami (talk) 01:53, 15 December 2011 (UTC)[reply]

New Dawn Data[edit]

I am totally not competent to add to this article, but the newly-published data from Dawn presented at EGU (article here [7] and LOADS of info here [8]) seem to have a lot of additional facts that might improve the article. Kevin/Last1in (talk) 16:56, 25 April 2012 (UTC)[reply]

Classification[edit]

Its now classified as a protoplanet. Someone should update this. mentioned in this article: http://lightyears.blogs.cnn.com/2012/05/10/space-rock-vesta-promoted-to-protoplanet/?hpt=hp_c2. I dont think this should be classified as a GA until this is fixed. Arowhun (talk) 20:30, 10 May 2012 (UTC)[reply]

I don't think CNN quite understands what is meant by calling Vesta a "protoplanet." That is not a classification. There are small solar system bodies, dwarf planets, and planets. There is no "protoplanet" designation, that's just a description of its role in the solar system. --Volcanopele (talk) 21:01, 10 May 2012 (UTC)[reply]
Ironically the result of which is that there isn't an official classification for Asteroids either, though it's a commonly accepted term.
But yes Volcanopele is correct that 'protoplanet' is not an official designation as defined by the International Astronomical Union, Vesta has not been reclassified and the Dawn science team do not have that authority to even if it were. And even if it were the case, that still wouldn't preclude it also being considered an asteroid, the larger Ceres has not stopped being referred to as an asteroid since being properly classified a dwarf planet. CNN (and I notice a few sites have run with this) has just got the wrong end of the stick. ChiZeroOne (talk) 21:32, 10 May 2012 (UTC)[reply]
Until the IAU changes its designation, Vesta is still best described as an asteroid. Actually, the IAU makes little differentiation between asteroid and dwarf planet. It's far more important to CNN than the IAU.--RadioFan (talk) 22:59, 10 May 2012 (UTC)[reply]
1. "protoplanet" is not anything like an official rank, like for example corporal vs. captain, it is a scientific term explaining that the planet in question emerged at a very early stage of the solar system history and is preserved in that state, Vesta could f.ex. be both a protoplanet and a minor planet,
2. how IAU labels planets out there seems to be pretty confused, it's time we think of the planets in their natural kinds, not in some kind of convenience on in what table the planet should be registered – AFAIK IAU don't handle lists of extrasolar planets, so we should try to use a better definition than that obsolete one. Rursus dixit. (mbork3!) 18:14, 11 May 2012 (UTC)[reply]

East/West[edit]

Moving here:

The eastern and western hemispheres show markedly different terrains. From preliminary spectral analyses of the Hubble Space Telescope images, the eastern hemisphere appears to be some kind of high-albedo, heavily cratered "highland" terrain with aged regolith, and craters probing into deeper plutonic layers of the crust. On the other hand, large regions of the western hemisphere are taken up by dark geologic units thought to be surface basalts, perhaps analogous to the lunar maria.

We should be able to update this from Dawn. Also, 'east' and 'west' have the opposite meanings for Hubble and the Dawn team (off by 155°), so the terms are ambiguous. — kwami (talk) 09:00, 25 August 2012 (UTC)[reply]

Removed unfilled references above. Tarl.Neustaedter (talk) 23:25, 24 August 2015 (UTC)[reply]

2010-2011[edit]

The 2010-2011 section in "Visibility" seems irrelevant to me. Should it be deleted? VirtualDave 23:17, 4 October 2012 (UTC) — Preceding unsigned comment added by VirtualDave (talk • contribs)

Hydrostatic Equilibrium[edit]

For its current rotation rate Vesta's equilibrium figure would have an oblateness of 0.128. Its actual oblateness is 0.21. http://www.lpi.usra.edu/meetings/lpsc2013/pdf/2115.pdf — Preceding unsigned comment added by 173.20.245.205 (talk) 17:55, 16 August 2013 (UTC)[reply]

Something similar is true of many of the round moons of Saturn (list of satellite planemos). Vesta's situation is especially similar to that of Phoebe, which has also been battered out of an obviously round shape. --JorisvS (talk) 13:28, 17 August 2013 (UTC)[reply]
Interesting, I've read that about Iapetus but not Saturn's other moons. I did some searching and found this reference http://www.geoinf.fu-berlin.de/publications/denk/2007/ThomasEtAl_SaturnMoonsShapes_Icarus_2007.pdf which doesn't show a large difference in the observed and predicted oblateness for Saturn's other moon. Have you seen something else?

Agmartin (talk) 17:40, 17 August 2013 (UTC)[reply]

Dawn at Vesta: testing the protoplanetary paradigm http://www.sciencemag.org/content/336/6082/684 states in note 19 "Vesta’s shape and the values of J2, C22, and S22 (C22,0.0043590 T 0.0000003; S22, 0.000254 T 0.000005) indicate that Vesta is not currently in hydrostatic equilibrium," (search for title on http://scholar.google.com/ if unable to view sciencemag articles), also discussed by the authors in THE GRAVITY FIELD OF VESTA AND IMPLICATIONS FOR INTERIOR STRUCTURE http://www.lpi.usra.edu/meetings/lpsc2012/pdf/2600.pdf Agmartin (talk) 17:51, 17 August 2013 (UTC)[reply]

Deviation from triaxial ellipsoid[edit]

How much does Vesta deviate from a triaxial ellipsoid when ignoring the Rheasilvia basin? --JorisvS (talk) 14:58, 2 April 2014 (UTC)[reply]

Topography relative to a bi-axial ellipsoid 285km x 285km x 229 km (this is not the hydrostatic-equilibrium ellipsoid) extends from 13.96 miles (22.47 kilometers) below to 12.11 miles (19.48 kilometers) above. http://dawn.jpl.nasa.gov/multimedia/vesta_Topography_map.asp Agmartin (talk) 21:03, 2 April 2014 (UTC)[reply]
You may find these two more useful as they include a scale http://www.hou.usra.edu/meetings/lpsc2014/pdf/1785.pdf http://www.hou.usra.edu/meetings/vesta2014/pdf/2027.pdf
Okay, thanks. But that includes Rheasilvia, doesn't it? And what would be the hydrostatic equilibrium ellipsoids? --JorisvS (talk) 21:20, 2 April 2014 (UTC)[reply]
Feralia Planitia on the equator has about the same depth relative to that bi-axial ellipsoid as RheaSilva.Agmartin (talk) 20:20, 3 April 2014 (UTC)[reply]
If equilibrium shape has oblateness of 0.128 and the volume is the same as for the bi-axial ellipsoid I calculate the dimensions would be 277km x 277km x 242km. I haven't seen the topography relative to this.Agmartin (talk) 20:20, 3 April 2014 (UTC)[reply]
Why that oblateness? And what about a triaxial ellipsoid? --JorisvS (talk) 20:31, 3 April 2014 (UTC)[reply]
Oblateness is from http://www.lpi.usra.edu/meetings/lpsc2013/pdf/2115.pdf "the current rotation rate of Vesta corresponds to an equilibrium figure with flattening factor feq = 0.128, where f is defined as (a-c)/a with a and c representing the equatorial and polar radii."
How did they calculate the hydrostatic flattening factor as f=0.128 for its current rotation rate? --JorisvS (talk) 15:58, 7 April 2014 (UTC)[reply]

To me it looks like there are several large, degraded craters on Vesta beside Rheasilivia/Veneneia. Is that what Feralia Planitia is? — kwami (talk) 21:32, 3 April 2014 (UTC)[reply]

It looks like that to me, too. According to this, it is. --JorisvS (talk) 11:09, 4 April 2014 (UTC)[reply]

Notes Section[edit]

維斯塔 wéisītǎ, with an obscure ī, is the closest Chinese approximation of the Latin pronunciation westa.

"Obscure i" is not a correct linguistic term--can we give IPA here, or a proper description? — Preceding unsigned comment added by 69.60.7.34 (talk) 15:13, 9 March 2015 (UTC)[reply]

See Mandarin Chinese phonology#Syllabic consonants. Double sharp (talk) 17:32, 10 November 2021 (UTC)[reply]

Redlink on Claudia crater[edit]

I removed the wikilink on Claudia crater in a photo caption, because it adds nothing useful. Nobody is going to write an article about a tiny crater which has the sole distinction of being used for the zero meridian on Vesta. That crater has no other distinguishing characteristics that would justify an article, so restoring the wikilink will leave this permanently redlinked. Is there any point to doing that?

WP:WTAF was written specifically for lists, but it applies in general articles as well, as a variation of WP:OVERLINK. No need to create links that just make the text harder to read. Tarl.Neustaedter (talk) 17:47, 8 October 2015 (UTC)[reply]

I see, feel free to remove the link again. I reverted you because I thought that it was a crater of some significance, which have some precedent of becoming articles, e.g. the blulinked entries in List of craters on Mars). I see now that Claudia is quite small and has no significance beside defining the meridian of Vesta. For this reason, I agree with removing the link. I still think that WP:WTAF does not apply here, however. A2soup (talk) 17:57, 8 October 2015 (UTC)[reply]
Done. Thanks, Tarl.Neustaedter (talk) 20:57, 8 October 2015 (UTC)[reply]
And I stand corrected. There is an article on Claudia crater. It's been there since 2012, although under a name I didn't think to look for. It's only a stub, but since it's been around for three years, it's not likely to get deleted. Tarl.Neustaedter (talk) 00:53, 12 October 2015 (UTC)[reply]

Rotational velocity[edit]

The article states that the equatorial rotation velocity of Vesta is 257.5 m/s. This however is the orbital velocity of a Low Vesta Orbit. Using the other numbers, 572.6 km for equatorial diameter and 5.342 h for rotational period I get an equatorial rotation velocity of 93.54 m/s. Should I replace the value? The 257.5 m/s number is not from an external source anyway.46.230.130.173 (talk) 19:38, 29 November 2015 (UTC)[reply]

Hi, thanks for catching that. It would be better if you can find a reliable source that gives the correct numbers rather than calculate them yourself, which is original research. Gap9551 (talk) 20:13, 29 November 2015 (UTC)[reply]
User:46.230.130.173 is correct in their calculations.
Are external references really needed? This is pretty simple math:
Velocity of an object moving in circular path is Circumference divided by Period.
Circumference = PI*Diameter = PI*(572,600m) = 1,798,876 m.
Period = 5.342 h = 19,230.2 sec.
Velocity = Circumference/Period = 1,798,876 m / 19,230.2 sec = 93.54 m/s.
...
The 257.5 m/s velocity corresponds to an orbit with semi-major axis of 317,400 meters (an altitude about 31.1 kilometers above the chosen 572.6 km diameter, for a circular orbit).
From Basic Keplerian Orbital Dynamics:
a = 1/(2/r-v^2/GM), where...
a = Semimajor Axis,
v = Orbital Velocity,
r = Vesta Radius = Diameter/2 = 572,600m km / 2 = 286,300 meters, and
GM = Standard gravitational parameter = vesta_Mass * gravitational_Constant = 2.59076e20 kg * 6.67408e-11 m3 kg-1 s-2 = 1.72909e+10 m^3/s^2,
a = 1/(2/r-v^2/GM) = 1/ (2/(286,300 meters)-((257.5 m/s)^2)/1.72909e+10 m^3/s^2)
a = 317,400 meters
--Faulx_Eve 13:20 , 18 May 2016 (UTC)

External links modified[edit]

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External links modified[edit]

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External links modified[edit]

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External links modified[edit]

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External links modified (January 2018)[edit]

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Ceres MOID[edit]

It would be interesting to know how close Vesta can get to Ceres since they can meet if you look on their orbits from "above". 212.186.0.174 (talk) 06:35, 20 May 2019 (UTC)[reply]

Their orbits do not intersect. Ruslik_Zero 20:49, 21 May 2019 (UTC)[reply]
Not only they don't intersect, the orbit of Ceres is entirely outside of Vesta's orbit. Ceres has a perihelion that is just barely inside of Vesta's aphelion, but not at the same place, so even when looking from celestial north (as opposed to "above"), the orbits don't meet. Either way, WP:NOTFORUM item 4 probably applies here. Tarl N. (discuss) 21:04, 21 May 2019 (UTC)[reply]
I'm not asking whether their orbits intersect but what the Ceres MOID of Vesta is. 212.186.0.174 (talk) 13:52, 23 May 2019 (UTC)[reply]
Or if it's too unclear due to its name, how close they can come to each other. 212.186.0.174 (talk) 13:54, 23 May 2019 (UTC)[reply]
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