Wednesday, August 14, 2019

RHEASILVIA PHOTOGRAPHED BY NASA DAWN MISSION (2007-2018)



NASA DAWN MISSION (2007-2018)
Rheasilvia (22,2500 m / 22.5 km - 73,8189 ft / 14 mi) 
Currently the tallest mountain known in the Solar System 
PROTOPLANET VESTA 

About this image
The black-and-white perspective view was made by laying a global image mosaic from Dawn's survey phase (1,700 miles or 2,750 kilometers in altitude) over a topographic shape model. 
The colorized view was made by laying a color-coded height map over the topography. Red indicates higher areas and blue indicates lower areas. 
A still image showing the black-and-white view from the Rheasilvia rim, with the corresponding colorized topography image, is also included here. 
The images used to create these vistas were obtained by Dawn's framing camera from Aug. 11 to Nov. 2, 2011.

The Mountain
Rheasilvia (22,2500 m / 22.5 km - 73,8189 ft / 14 mi) is the tallest mountain known in the Solar System and the most prominent surface feature on the asteroid/ proto planet Vesta. 
Rheasilvia is thought to be an impact crater. It is 505 km (314 mi) in diameter, which is 90% the diameter of Vesta itself, and is 95% the mean diameter of Vesta. However, the mean is affected by the crater itself. It is 89% the mean equatorial diameter of 569 km (354 mi), making it one of the largest craters in the Solar System.  The crater partially obscures an earlier crater, named Veneneia, that at 395 km (245 mi) is almost as large.
Rheasilvia was discovered in Hubble Space Telescope images in 1997, but was not named until the arrival of the Dawn spacecraft in 2011.
It is named after Rhea Silvia, a mythological vestal virgin and mother of the founders of Rome, Romulus and Remus.

The Mission
Dawn is a retired space probe launched by NASA in September 2007 with the mission of studying two of the three known protoplanets of the asteroid belt, Vesta and Ceres. 
It was retired on 1 November 2018 and it is currently in an uncontrolled orbit around its second target, the dwarf planet Ceres. 
Dawn is the first spacecraft to orbit two extraterrestrial bodies, the first spacecraft to visit either Vesta or Ceres, and the first to visit a dwarf planet, arriving at Ceres in March 2015, a few months before New Horizons flew by Pluto in July 2015.
Dawn entered orbit around Vesta on July 16, 2011, and completed a 14-month survey mission before leaving for Ceres in late 2012.It then entered orbit around Ceres on March 6, 2015.
NASA considered, but decided against, a proposal to visit a third target.
On October 19, 2017, NASA announced that the mission would be extended until the probe's hydrazine fuel supply was used up
On November 1, 2018, NASA announced that the Dawn spacecraft had finally exhausted all of its hydrazine fuel, thus ending its mission. The satellite is currently in an uncontrolled state about Ceres.
The Dawn mission was managed by NASA's Jet Propulsion Laboratory, with spacecraft components contributed by European partners from Italy, Germany, France, and the Netherlands. It was the first NASA exploratory mission to use ion propulsion, which enabled it to enter and leave the orbit of two celestial bodies. Previous multi-target missions using conventional drives, such as the Voyager program, were restricted to flybys.

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2019 - Wandering Vertexes...
by Francis Rousseau