Editing 4 Vesta (section)

==Exploration==
{{stack|
[[File:Animation of Dawn trajectory.gif|thumb|Animation of '' Dawn''{{'s}} trajectory from 27 September 2007 to 5 October 2018<br />{{legend2|magenta| ''[[Dawn (spacecraft)|Dawn]]'' }}{{·}}{{legend2|Royalblue|[[Earth]]}}{{·}}{{legend2|Gold|[[Mars]]}}{{·}}{{legend2|Cyan|4 Vesta }}{{·}}{{legend2|lime|[[Ceres (dwarf planet)|1 Ceres]]}}]]
[[File:PIA17937-MarsCuriosityRover-FirstAsteroidImage-20140420.jpg|thumb|First image of [[asteroid]]s ([[Ceres (dwarf planet)|Ceres]] and Vesta) taken from [[Mars]]. The image was made by the [[Curiosity (rover)|''Curiosity'' rover]] on 20 April 2014.]]
[[File:Animation of Dawn trajectory around 4 Vesta.gif |thumb |Animation of ''[[Dawn (spacecraft)|Dawn]]''{{'s}} trajectory around 4 Vesta from 15 July 2011 to 10 September 2012<br />{{legend2|magenta| ''[[Dawn (spacecraft)|Dawn]]''}}{{·}}{{legend2| Lime |4 Vesta}}]]
}}
In 1981, a proposal for an asteroid mission was submitted to the [[European Space Agency]] (ESA). Named the Asteroidal Gravity Optical and Radar Analysis (AGORA), this [[spacecraft]] was to launch some time in 1990–1994 and perform two flybys of large asteroids. The preferred target for this mission was Vesta. AGORA would reach the asteroid belt either by a [[gravitational slingshot]] trajectory past Mars or by means of a small [[ion engine]]. However, the proposal was refused by the ESA. A joint [[NASA]]–ESA asteroid mission was then drawn up for a Multiple Asteroid Orbiter with Solar Electric Propulsion (MAOSEP), with one of the mission profiles including an orbit of Vesta. NASA indicated they were not interested in an asteroid mission. Instead, the ESA set up a technological study of a spacecraft with an ion drive. Other missions to the asteroid belt were proposed in the 1980s by France, Germany, Italy and the United States, but none were approved.<ref name="ulivi_harland08"/> Exploration of Vesta by fly-by and [[Deep Impact (spacecraft)|impacting penetrator]] was the second main target of the first plan of the multi-aimed Soviet [[Vesta mission]], developed in cooperation with European countries for realisation in 1991–1994 but canceled due to the [[dissolution of the Soviet Union]].
[[File:Dawn Flight Configuration 2.jpg|thumb|right|Artist's conception of ''[[Dawn (spacecraft)|Dawn]]'' orbiting Vesta]]
In the early 1990s, NASA initiated the [[Discovery Program]], which was intended to be a series of low-cost scientific missions. In 1996, the program's study team recommended a mission to explore the asteroid belt using a spacecraft with an ion engine as a high priority. Funding for this program remained problematic for several years, but by 2004 the ''[[Dawn (spacecraft)|Dawn]]'' vehicle had passed its critical design review<ref name="Russell2007"/> and construction proceeded.{{citation needed|date=August 2022}}

It launched on 27 September 2007 as the first space mission to Vesta. On 3 May 2011, ''Dawn'' acquired its first targeting image 1.2 million kilometers from Vesta.<ref name="pr2011-138"/> On 16 July 2011, NASA confirmed that it received telemetry from ''Dawn'' indicating that the spacecraft successfully entered Vesta's orbit.<ref name="Vega2011"/> It was scheduled to orbit Vesta for one year, until July 2012.<ref name="Dawntimeline"/> ''Dawn''{{'s}} arrival coincided with late summer in the southern hemisphere of Vesta, with the large crater at Vesta's south pole ([[Rheasilvia]]) in sunlight. Because a season on Vesta lasts eleven months, the northern hemisphere, including anticipated compression fractures opposite the crater, would become visible to ''Dawn''{{'s}} cameras before it left orbit.<ref name="DawnMission"/> ''Dawn'' left orbit around Vesta on 4 September 2012 {{nowrap|11:26 p.m. PDT}} to travel to [[Ceres (dwarf planet)|Ceres]].<ref name="Dawndeparture"/>

NASA/DLR released imagery and summary information from a survey orbit, two high-altitude orbits (60–70&nbsp;m/pixel) and a low-altitude mapping orbit (20&nbsp;m/pixel), including digital terrain models, videos and atlases.<ref name="Russell2013"/><ref name="Roatsch2012"/><ref name="Roatsch2013"/><ref name="journeyaboveVesta"/><ref name="dawn_gis"/><ref name="NASADawn"/> Scientists also used ''Dawn'' to calculate Vesta's precise mass and gravity field. The subsequent determination of the J<sub>2</sub> component yielded a core diameter estimate of about 220&nbsp;km assuming a crustal density similar to that of the HED.<ref name="Russell2013"/>

''Dawn'' data can be accessed by the public at the [[UCLA]] website.<ref name="Dawnpublic"/>

===Observations from Earth orbit===
<gallery>
File:Vesta spectral map HST1994.jpg|[[Albedo]] and spectral maps of 4 Vesta, as determined from Hubble Space Telescope images from November 1994
File:Vesta elevation map HST1996.jpg|Elevation map of 4 Vesta, as determined from Hubble Space Telescope images of May 1996
File:Vesta-Elevation.jpg|Elevation diagram of 4 Vesta (as determined from [[Hubble Space Telescope]] images of May 1996) viewed from the south-east, showing [[Rheasilvia]] crater at the south pole and [[Feralia Planitia]] near the equator
File:Vesta-HST-Color.jpg|Vesta seen by the [[Hubble Space Telescope]] in May 2007
File:Iau dozen.jpg|The [[IAU definition of planet#First draft proposal|2006 IAU draft proposal]] on the definition of a planet listed Vesta as a candidate.<ref name="IAU-draft2006"/> Vesta is shown fourth from the left along the bottom row.
</gallery>

===Observations from ''Dawn''===
Vesta comes into view as the [[Dawn (spacecraft)|''Dawn'' spacecraft]] approaches and enters orbit:
<gallery>
<!-- File:Vesta image by Dawn probe.jpg|Vesta from 265,000&nbsp;km<br />(14 June 2011) too fuzzy? -->
File:Vesta 20110701 cropped.jpg|Vesta from 100,000&nbsp;km<br />(1 July 2011)
File:Dawn-image-070911.jpg|Vesta from 41,000&nbsp;km<br />(9 July 2011)
File:Vesta from Dawn, July 17.jpg|In orbit at 16,000&nbsp;km<br />(17 July 2011)
File:Vesta 4.jpg|In orbit from 10,500&nbsp;km<br />(18 July 2011)
File:Vesta darkside.jpg|The northern hemisphere from 5,200&nbsp;km<br />(23 July 2011)
File:Vesta Full-Frame.jpg|In orbit from 5,200&nbsp;km<br />(24 July 2011)
File:Vesta 20110731.jpg|In orbit from 3,700&nbsp;km<br />(31 July 2011)
File:Vesta Rotation.gif|Full rotation<br />(1 August 2011)
File:Vesta full mosaic.jpg|Composite greyscale image
File:Vesta Cratered terrain with hills and ridges.jpg|Cratered terrain with hills and ridges<br />(6 August 2011)
File:Vesta densely cratered terrain near terminator.jpg|Densely cratered terrain near terminator<br />(6 August 2011)
File:Vesta Craters in various states of degradation.jpg|Vestan craters in various states of degradation, with troughs at bottom<br />(6 August 2011)
File:Central Mound at the South Pole Asteroid Vesta Hillshade.png|Hill shaded central mound at the south pole of Vesta<br />(2 February 2015)
</gallery>

==== True-color images ====
<gallery>
Vesta in natural color.jpg
Vesta-SouthPole.png
Vesta 5755-728.png
</gallery>

Detailed images retrieved during the high-altitude (60–70&nbsp;m/pixel) and low-altitude (~20&nbsp;m/pixel) mapping orbits are available on the Dawn Mission website of JPL/NASA.<ref>{{cite web |url=http://dawn.jpl.nasa.gov/multimedia/vesta_dawn_gallery_2.asp |title=Dawn Mission website of JPL/NASA |date=22 October 2018 }}</ref>