Полет АМС Dawn к Весте и Церере

[Georgij]

Интересно, по завершени миссии на Церере что удумает НАСА сделать с Рассветом?

Варианты:

1. Тупо отключить связь или дождаться, пока она сама со временем отключится "от старости".

2. На последних запасах ксенона вывести на рисковано сверхнизкую орбиту - попробовать поснимать поближе, в 100 м над пиками гор...

3. Символически разбить о поверхность.

4. На последних запасах ксенона - отправить в свободное плавание навстречу какой-то пролетной комете или астероиду.

5. Попытаться прицерериться относительно мягк - На последних запасах гидразина (тут надо смотреть ХС тех остатков ксенона и первую космическую для Цереры)


А чО? - вон Неар немного передавал с Эроса? (тут правда покрупнее тело

на палладу уже не хватит горючки?

[Bizonich]

Интересно, ведь. На кратерах, отдельно стоящих, выбросы породы темные.
http://dawn.jpl.nasa.gov/multimedia/images/imageoftheday/201111/IOTD-107_full.jpg
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111015
А на тех, которые попали в старый кратер, светлые.
http://dawn.jpl.nasa.gov/multimedia/images/imageoftheday/201111/IOTD-109_full.jpg
 С чем это может быть связано, есть ли какая закономерность? Может от материала прилетевшего тела?

[Oleg]

Меня не покидает впечатление очень рыхлой поверхности. Многокилометрового слоя мягкой пушистой цементной пыли.

Интересно, ведь. На кратерах, отдельно стоящих, выбросы породы темные.

По аналогии:
астероид 21 Лютеция
http://www.esa.int/esaCP/SEMG93HURTG_index_0.html
Ядро с километровым слоем пыли.
Веста скопление нескольких планетезималей покрытых слоем пыли и как следствие, если кратер между ними, то глубокий и светлый - попал в пыль. Если темный значит попал в одно из ядер.

[Bizonich]

А не высока ли плотность, в районе 3,5 г\см3, что дря Весты, что для Лютеции, для подобного строения? Веста ведь астероид V-типа. Значит старая информация о том, что она единственная в своем классе не верна.
Вещество же астероидов V-типа может включать наряду с пироксенами и полевые шпаты, а по составу быть похожим на земные базальты.

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http://www.nasa.gov/multimedia/videogallery/index.html?media_id=122644631

This 3-D video incorporates images from the framing camera instrument aboard NASA's Dawn spacecraft from July to August 2011. The images were obtained as Dawn approached Vesta and circled the giant asteroid during the mission's survey orbit phase. Survey orbit took place at an altitude of about 1,700 miles (2,700 kilometers). To view this image in 3-D use red-green, or red-blue, glasses (left eye: red; right eye: green/blue). Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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Dawn Soars Over Asteroid Vesta in 3-D
For 3D glasses visit http://go.usa.gov/5kI

PASADENA, Calif. – Glide over the giant asteroid Vesta with NASA's Dawn spacecraft in a new 3-D video. Dawn has been orbiting Vesta since July 15, obtaining high-resolution images of its bumpy, cratered surface and making other scientific measurements.

The new video is available online at: http://www.nasa.gov/multimedia/videogallery/index.html?media_id=122644631 . Best viewed with red-blue glasses, the video incorporates images from Dawn's framing camera from July to August 2011. It was created by Dawn team member Ralf Jaumann of the German Aerospace Center (DLR).

The images were obtained when Dawn was making its approach to Vesta, and while orbiting the giant asteroid in its first science orbit, known as survey orbit, at an altitude of about 1,700 miles (2,700 kilometers). The video begins with a global view of Vesta from the plane of its equator, where a mysterious band of linear ridges and troughs can be seen. The movie cuts to a flyover of young craters in the northern hemisphere, whose peculiar alignment has led some scientists to refer to them as the "snowman." Then this virtual tour of Vesta takes the viewer around a massive mountain at the south pole of Vesta that is about 16 miles (25 kilometers) high, or more than twice the height of Mt. Everest.

"If you want to know what it's like to explore a new world like Vesta, this new video gives everyone a chance to see it for themselves," Jaumann said. "Scientists are poring over these images to learn more about how the craters, hills, grooves and troughs we see were created."

Vesta is the second most massive object in the asteroid belt between Mars and Jupiter. Dawn is currently spiraling down to its low altitude mapping orbit, which will bring the spacecraft to about 130 miles (210 kilometers) above Vesta's surface.

"Dawn's data thus far have revealed the rugged topography and complex textures of the surface of Vesta, as can be seen in this video," said Carol Raymond, deputy principal investigator at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Soon, we'll add other pieces of the puzzle such as the chemical composition, interior structure, and geologic age to be able to write the history of this remnant protoplanet and its place in the early solar system."

Dawn launched in September 2007 and arrived at Vesta on July 15, 2011. Following a year at Vesta, the spacecraft will depart in July 2012 for the dwarf planet Ceres, where it will arrive in 2015.

http://www.nasa.gov/mission_pages/dawn/news/dawn20111201.html

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Trio of NASA Missions Named 'Best of What's New'

PASADENA, Calif. -- NASA's Dawn, Mars Science Laboratory and MESSENGER missions have earned recognition from Popular Science magazine as innovations worthy of the publication's "Best of What's New" Award in the aviation and space category.

Dawn and Mars Science Laboratory are managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif. Dawn is currently orbiting and exploring the massive main-belt asteroid Vesta. The Mars Science Laboratory and its Curiosity rover launched on Nov. 26 on a journey to the Red Planet, where the rover will look for signs of past or present habitability.

The MESSENGER mission is currently orbiting Mercury.

More information on the award winners is online at: http://www.popsci.com/bown/2011/category/aviation-amp-space .

JPL, a division of the California Institute of Technology in Pasadena, manages Dawn and Mars Science Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.

Sean Solomon, of the Carnegie Institution of Washington, leads the MESSENGER mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft for NASA.

http://www.nasa.gov/mission_pages/dawn/news/award20111130.html

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Dawn Journal[/size]
November 29, 2011

http://dawn.jpl.nasa.gov/mission/journal_11_29_11.asp

[Space Alien]

Rocks from Vesta – Part 2: Howardites

http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111203
 

 
The HED (howardite, eucrite and diogenite) meteorites are a large group of meteorites believed to originate from Vesta, a hypothesis that is consistent with current Dawn observations. Howardites are regolith breccia rocks, meaning that they formed through the grinding and fusion of rock and dust that occurs during meteor impacts on the surface of Vesta. Howardites are comprised of fragments of eucrite and diogenite of varying grain sizes, which can be seen in this picture of the Bununu howardite. This sample weighs 217 grams and was recovered in 1942 in Africa. Along with fragments of eucrite and diogenite, some howardites also contain solar wind implanted noble gasses, which confirms that they once resided on the surface of their parent body. This makes howardites a good laboratory analog for spectral and chemical measurements that will be made of the Vestan surface by Dawn.

The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington D.C. UCLA is responsible for overall Dawn mission science.

[Space Alien]

Dawn Soars Over Asteroid Vesta in 3-D



PASADENA, Calif. - Glide over the giant asteroid Vesta with NASA's Dawn spacecraft in a new 3-D video.  Dawn has been orbiting Vesta since July 15, obtaining high-resolution images of its bumpy, cratered surface and making other scientific measurements.

The new video is available online at: http://www.jpl.nasa.gov/video/index.cfm?id=1041 . Best viewed with red-blue glasses, the video incorporates images from Dawn's framing camera from July to August 2011. It was created by Dawn team member Ralf Jaumann of the German Aerospace Center (DLR).

The images were obtained when Dawn was making its approach to Vesta, and while orbiting the giant asteroid in its first science orbit, known as survey orbit, at an altitude of about 1,700 miles (2,700 kilometers). The video begins with a global view of Vesta from the plane of its equator, where a mysterious band of linear ridges and troughs can be seen. The movie cuts to a flyover of young craters in the northern hemisphere, whose peculiar alignment has led some scientists to refer to them as the "snowman." Then this virtual tour of Vesta takes the viewer around a massive mountain at the south pole of Vesta that is about 16 miles (25 kilometers) high, or more than twice the height of Mt. Everest.

"If you want to know what it's like to explore a new world like Vesta, this new video gives everyone a chance to see it for themselves," Jaumann said. "Scientists are poring over these images to learn more about how the craters, hills, grooves and troughs we see were created."

Vesta is the second most massive object in the asteroid belt between Mars and Jupiter. Dawn is currently spiraling down to its low altitude mapping orbit, which will bring the spacecraft to about 130 miles (210 kilometers) above Vesta's surface.

"Dawn's data thus far have revealed the rugged topography and complex textures of the surface of Vesta, as can be seen in this video," said Carol Raymond, deputy principal investigator at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Soon, we'll add other pieces of the puzzle such as the chemical composition, interior structure, and geologic age to be able to write the history of this remnant protoplanet and its place in the early solar system."

Dawn launched in September 2007 and arrived at Vesta on July 15, 2011. Following a year at Vesta, the spacecraft will depart in July 2012 for the dwarf planet Ceres, where it will arrive in 2015.

Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.

http://www.jpl.nasa.gov/news/news.cfm?release=2011-366

[Space Alien]

Rocks from Vesta – Part 1: Eucrites



The HED (howardite, eucrite and diogenite) meteorites are a large group of meteorites believed to originate from Vesta, a hypothesis that is consistent with current Dawn observations. The eucrites are crystallized lavas that have the composition of basalt, the most common lava type on the Earth. The QUE 97053 (left) and EET 90020 (right) eucrites, pictured here, were recovered in Antarctica. These images are of thin slices of the meteorites as viewed through a polarizing microscope. The white bars in the images, each 2.5 millimeters long, indicate the scale. When polarized light passes through thin slices of rock, different minerals have different colors. QUE97053 (left) consists mostly of elongated gray crystals of feldspar (calcium aluminum silicate) and brightly colored grains of pyroxene (magnesium iron silicate). The texture of this rock is what would be expected from crystallization of a molten magma. EET90020 (right) has similar mineralogy but a recrystallized texture of equant grains formed by later heating. Equant grains have the same or roughly the same dimensions in all directions. Eucrites like these comprise some fraction of Vesta's surface. Their compositions can be compared with observations from various instruments aboard Dawn. They can be compared with the VIR (Visible and Infrared Imaging Spectrometer) spectra to determine mineralogy and with the GRaND (Gamma Ray and Neutron Detector) observations to calibrate and interpret the GRaND instrument's responses.

The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington D.C. UCLA is responsible for overall Dawn mission science.

http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111202

[Space Alien]

Rocks from Vesta – Part 3: Diogenites




The HED (howardite, eucrite and diogenite) meteorites are a large group of meteorites believed to originate from Vesta, a hypothesis that is consistent with current Dawn observations. The diogenites originated deep within the crust of Vesta and resemble rocks, both in texture and composition, which we find in the lower crust of the Earth. The QUE 99050 (left) and GRA 98108 (right) diogenites, pictured here, were recovered in Antarctica. These images are of thin slices of the meteorites as viewed through a polarizing microscope. The white bars in the images, each 2 millimeters long, indicate the scale. When polarized light passes through thin slices of rock, different minerals have different colors. QUE 99050 (left) consists of large gray and yellow crystals of pyroxene (magnesium-iron silicate) and is a subgroup of diogenite called "orthopyroxenitic diogenite" (orthopyroxenite is the name of a rock composed primarily of the mineral orthopyroxene). GRA 98108 (right) has a more mafic (i.e. magnesium and iron rich) mineralogy, consisting of roughly equal portions of pyroxene and the much brighter colored olivine, a silica-poor iron magnesium-iron silicate. This olivine-rich "harzburgitic diogenite" (harzburgite is the name given to a rock composed of a mixture of the minerals orthopyroxene and olivine) is thought to represent the most deep-seated rocks from Vesta that we have in the meteorite collection. Diogenites like these comprise some fraction of Vesta's lower crust, and their compositions can be compared with observations from various instruments aboard Dawn. They can be compared with the VIR (Visible and Infrared Imaging Spectrometer) spectra to determine mineralogy and with the GRaND (Gamma Ray and Neutron Detector) observations to calibrate and interpret the GRaND instrument's responses. Similar rocks have likely been excavated by large impacts, such as the one that formed the Rheasilvia basin at the south pole of Vesta.

The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington D.C. UCLA is responsible for overall Dawn mission science.


http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111204

[Space Alien]

Астрономы выпустили цветную "минеральную" карту астероида Веста
http://ria.ru/science/20111206/508203441.html


New NASA Dawn Visuals Show Vesta's 'Color Palette'

http://www.jpl.nasa.gov/news/news.cfm?release=2011-375

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Mission Status

December 8, 2011
Dawn Reaches Planned Orbit Altitude
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Dawn has reached its target altitude, averaging 210 kilometers (130 miles) above Vesta.

On Dec. 3, while the spacecraft was turning in preparation for a final brief period of ion thrusting to refine its orbit, protective software detected a discrepancy in the orientation and put the spacecraft into safe mode. The discrepancy was a result of the spacecraft computing and then using a turn rate that was slightly too high. The operations team quickly established that the spacecraft was healthy, and on Dec. 5 they commanded it out of safe mode.

Mission planners already had several more windows planned for ion thrusting in order to make further fine adjustments to the orbit. Lengthening one of those windows allows sufficient time to compensate for the safe mode.

Science observations in the new orbit are scheduled to begin on Dec. 12.

http://dawn.jpl.nasa.gov/mission/status.asp

[Space Alien]

Is Vesta the "Smallest Terrestrial Planet?"

Dec 9, 2011: NASA's Dawn spacecraft spent the last four years voyaging to asteroid Vesta – and may have found a planet.

Vesta was discovered over two hundred years ago but, until Dawn, has been seen only as an indistinct blur and considered little more than a large, rocky body. Now the spacecraft's instruments are revealing the true complexity of this ancient world.

"We're seeing enormous mountains, valleys, hills, cliffs, troughs, ridges, craters of all sizes, and plains," says Chris Russell, Dawn principal investigator from UCLA. "Vesta is not a simple ball of rock. This is a world with a rich geochemical history. It has quite a story to tell!"

http://science.nasa.gov/media/medialibrary/2011/12/09/splash_strip.jpg/image_full

In fact, the asteroid is so complex that Russell and members of his team are calling it the "smallest terrestrial planet."

Vesta has an iron core, notes Russell, and its surface features indicate that the asteroid is "differentiated" like the terrestrial planets Earth, Mercury, Mars, and Venus.

Differentiation is what happens when the interior of an active planet gets hot enough to melt, separating its materials into layers. The light material floats to the top while the heavy elements, such as iron and nickel, sink to the center of the planet.

Researchers believe this process also happened to Vesta.

The story begins about 4.57 billion years ago, when the planets of the Solar System started forming from the primordial solar nebula. As Jupiter gathered itself together, its powerful gravity stirred up the material in the asteroid belt so objects there could no longer coalesce. Vesta was in the process of growing into a full-fledged planet when Jupiter interrupted the process.

Although Vesta's growth was stunted, it is still differentiated like a true planet.

"We believe that the Solar System received an extra slug of radioactive aluminum and iron from a nearby supernova explosion at the time Vesta was forming," explains Russell. "These materials decay and give off heat. As the asteroid was gathering material up into a big ball of rock, it was also trapping the heat inside itself."

As Vesta's core melted, lighter materials rose to the surface, forming volcanoes and mountains and lava flows.

"We think Vesta had volcanoes and flowing lava at one time, although we've not yet found any ancient volcanoes there," says Russell. "We're still looking. Vesta's plains seem similar to Hawaii's surface, which is basaltic lava solidified after flowing onto the surface.

Vesta has so much in common with the terrestrial planets, should it be formally reclassified from "asteroid" to "dwarf planet"?

"That's up to the International Astronomical Union, but at least on the inside, Vesta is doing all the things a planet does."

If anyone asks Russell, he knows how he would vote.

http://science.nasa.gov/science-news/science-at-nasa/2011/09dec_vestaplanet/

[sol]

никак не могу нагуглить - каковы планы по изменению орбиты аппарата у Весты и у Цереры?

Может кто поможет?

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никак не могу нагуглить - каковы планы по изменению орбиты аппарата у Весты и у Цереры?

Может кто поможет?

С Вестой все понятно - аппарат уже на самой низкой орбите, потом полетит обратно.
У Цереры - ближе к делу скажут.

[Salo]

http://www.infuture.ru/article/5282

Веста - самая маленькая земная планета?[/size]

Космический исследовательский зонд "Рассвет", принадлежащий NASA потратил около 4х лет на путешествие к астероиду Веста, и возможно, обнаружил не астероид, а планету.

Веста была открыта около 200 лет назад, но только сейчас с помощью американского аппарата "Рассвет" (Dawn) ученые могут узнать сложную структуру этого астероида.

"С помощью "Рассвета" мы можем наблюдать огромные горные хребты и долины, кратера и равнины разных размеров и типов" - говорит Крис Рассел (Chris Russell), главный исследователь проекта "Рассвет".

"Мы сделали вывод, что Веста - это не просто кусок скалы шарообразной формы. Это целый мир со сложной геохимической историей. Веста может многое нам рассказать" - продолжил исследователь.

На самом деле, этот астероид имеет настолько сложную структуру, что Крис Рассел и другие члены его команды называют его "самой маленькой земной планетой" или "самой маленькой планетой земного типа".

Веста - это один из крупнейших астероидов в главном астероидном поясе. и занимает первое место по массе среди всех астероидов и второе - по размеру после Паллады.
 Размеры Весты составляют 578

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Зонд "Заря" опустился на самую низкую орбиту и начал наиболее важный этап изучения астероида Веста

ЛОС-АНДЖЕЛЕС, 13 декабря. /Корр. ИТАР-ТАСС Алексей Качалин/. Американский межпланетный зонд "Dawn" /"Заря"/ в понедельник успешно снизился до высоты 210 км от поверхности астероида Веста и приступил к наиболее важному этапу его изучения. В течение 10 недель аппарату предстоит распознать состав элементов поверхности астероида и проанализировать особенности его гравитационного поля. Об этом сообщила Лаборатория реактивного движения НАСА в Пасадине /штат Калифорния/, откуда осуществляется управление зондом.

"Заря" выполнила серию сложных и одновременно изящных пируэтов, чтобы достичь самой близкой к Весте орбиты", - подчеркнул главный конструктор аппарата Марк Рэйман, руководящий программой полета в ЛРД. "Зонд сейчас находится в оптимальном положении для углубления знаний о тайнах астероида", - добавил он. Главная задача на данном этапе состоит в том, чтобы собрать максимальный объем данных для бортового детектора гамма-излучения и нейтронов. Кроме того, "Заре" поставлена задача на основе обследования гравитационного поля попытаться установить, каким образом распределена масса внутри астероида.

Астероид Веста, диаметр которого составляет 530 км, является вторым по величине телом в поясе астероидов между Марсом и Юпитером. Астрономы наблюдали за этим таинственным объектом с помощью наземных и космических телескопов "в течение примерно двух столетий", однако до экспедиции "Зари" не имели достаточно точного представления о поверхности астероида. Предполагается, что на Весте когда- то была вода, являющаяся одним из условий возникновения жизни.

"Заря" в августе вышла на первую из заданных орбит Весты на расстоянии 2735 км от поверхности. 29 сентября зонд снизился до высоты 680 км над астероидом, а сейчас - до высоты 210 км. Через 10 недель аппарат вернется на предыдущую орбиту /680 км/, чтобы довести до конца программу изучения небесного тела.

В июле 2012 года зонд, запущенный в сентябре 2007 года, отправится к следующему объекту изучения - малой планете Церера. Ее аппарат должен достигнуть в 2015 году. НАСА полагает, что тщательное обследование Весты и Цереры позволит углубить знания о происхождении нашей Солнечной системы и ее планет.

http://www.itar-tass.com/c19/295716.html

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Mission Status

December 13, 2011
Dawn Begins New Science Phase at Lowest Altitude

Dawn began a new set of science observations on schedule on Dec. 12 in its low altitude mapping orbit (LAMO) at an average altitude of 210 kilometers (130 miles). This phase will be the longest of the science campaigns at Vesta, lasting at least 10 weeks.

Dawn's investigations in this orbit will focus on measuring the elemental composition of the surface and subsurface material with the gamma ray and neutron detector and on mapping the interior structure by measuring Vesta's gravity field. In addition, the science camera and the visible and infrared mapping spectrometer will be used for some bonus observations. An overview of the plan for LAMO is in the Dawn Journal from Dec. 30, 2010, and further details will be in upcoming Dawn Journals.

The Dawn "image of the day" will take a break until Jan. 9. When it returns, there will be more spectacular views of this exotic world.

http://dawn.jpl.nasa.gov/mission/status.asp