Messenger (Даёшь Меркурий!)

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Deep Impact
http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=782

Date acquired: February 09, 2012
Image Mission Elapsed Time (MET): 237254445
Image ID: 1371698
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 27.52°
Center Longitude: 54.40° E
Resolution: 30 meters/pixel
Scale: The crater in the center of the image is 7 km (4.4 miles) in diameter
Incidence Angle: 41.3°
Emission Angle: 40.1°
Phase Angle: 28.1°

Of Interest: Although Mercury is replete with impact craters, it can be difficult to gauge their size in a meaningful way. This oblique image shows an unnamed crater that lies within the Rachmaninoff basin. It is a simple crater, characterized by its bowl-like shape, and lacks the central peak or peak ring of larger, complex craters. The famous Meteor Crater in Arizona, though also a simple crater, is five times smaller in diameter! (North is towards the upper left corner of the image.)

A Crack in the Floor
http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=780

Date acquired: January 27, 2012
Image Mission Elapsed Time (MET): 236192195
Image ID: 1320489
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 62.63°
Center Longitude: 348.5° E
Resolution: 21 meters/pixel
Scale: This image is 37 km (23 miles) wide from left corner to right corner
Incidence Angle: 80.6°
Emission Angle: 46.4°
Phase Angle: 127.1°

Of Interest: In this image, a portion of the 116 km- (73 mile-) diameter Abedin crater is visible. The floor of the crater is generally smooth, and hosts many small troughs that are interpreted to be graben. Graben form as the result of extensional (i.e. pull-apart) stresses, which in this case may have resulted from the cooling and solidification of either impact melt or volcanic fill inside Abedin, similar to that seen in other basins across Mercury.

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Год назад, 18 марта 2011 года, MESSENGER стал первым космическим аппаратом, вышедшим на орбиту Меркурия! Первоначальная научная программа на орбите завершилась вчера, а сегодня начинается расширенная, рассчитанная на один земной год.

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MESSENGER Mission News
March 19, 2012

http://messenger.jhuapl.edu/

MESSENGER Completes Primary Mission at Mercury, Settles in for Another Year

On March 17, 2012, MESSENGER successfully wrapped up a year-long campaign to perform the first complete reconnaissance of the geochemistry, geophysics, geologic history, atmosphere, magnetosphere, and plasma environment of the solar system's innermost planet. The following day, March 18, 2012, marked the official start of an extended phase designed to build upon those discoveries.

What MESSENGER has accomplished since its launch in August 2004 is "amazing," says MESSENGER Mission Systems Engineer Eric Finnegan, of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md.

"Six plus years of cruise operations, capped by a year of nearly flawless orbital operations, with an additional year of scientific return ahead in the harsh environment at 0.3 astronomical units (27,886,766 miles) from the Sun," he begins, checking off the list of mission accomplishments. All this "achieved with a 1,000 kg satellite, designed, built, and lunched in less than four years for a total mission cost of less than $450 million."

"This is a testament to the hundreds of innovative, talented, and dedicated engineers, technicians, and support personnel here at APL and around the world who contributed to this mission," he continues. "Before selection many said that the MESSENGER mission to inject a spacecraft into orbit around Mercury and map, in-detail, the surface and surrounding environment could not be achieved within the constricts of NASA's Discovery program. The APL team did it!"

MESSENGER's three flybys of Mercury solved the decades-old question of whether there are volcanic deposits on the planet's surface. But the detailed character and global distribution of volcanic materials remained poorly known until the arrival of MESSENGER in orbit about Mercury. MESSENGER orbital images have revealed volcanic vents measuring up to 25 kilometers (15.5 miles) across that appear to have once been sources for large volumes of very hot lava that, after eruption, carved valleys and created teardrop-shaped ridges in the underlying terrain.

Also noteworthy is the discovery from measurements of Mercury's gravity field that the planet has an unexpectedly complex internal structure, a finding that will be discussed in a paper to be published by Science Express on March 21, 2012, and at a press conference at the 43rd Lunar and Planetary Science Conference in The Woodlands, Texas.

"The last year has been a busy and rewarding one for the MESSENGER project," says MESSENGER Project Manager Peter Bedini, of APL in Laurel, Md. "As the engineering and operations teams closely monitored the spacecraft's response to Mercury's seasons, the science team was busy analyzing data and filling gaps in our understanding of the planet. Science results from the first year of orbital operations have influenced the observation plan for the second year, which we expect to be as busy as the first, and hope to be as rewarding."

http://messenger.jhuapl.edu/news_room/details.php?id=197

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Updated: MESSENGER Mercury Orbit Insertion Animation

With more than 99% of Mercury's surface imaged under similar illumination and viewing conditions, and with final spacecraft performance and final spacecraft orbit data available, MESSENGER's mission design team has updated the animation of MESSENGER's Mercury orbit insertion (MOI) maneuver. The largest and most important propulsive maneuver of the mission, MOI used more than 31% of the total propellant to transition the spacecraft's orbit center from the Sun to Mercury. About 2.5 weeks after MOI, after sufficient opportunity to monitor spacecraft health, temperature, and functionality, the primary science phase of the mission began.

This updated animation includes Mercury surface images from MESSENGER and a few extremely small areas with images from Mariner 10 flybys of Mercury in 1974 and 1975. "This animation features the best reconstructed orientation of the spacecraft, renderings of thruster flames as they occurred each second of MOI, as well as other details about the progress and orbit location relative to Mercury," says MESSENGER Mission Design Lead Engineer Jim McAdams.

The new MOI animation and a counterpart from March 2011 may be viewed near the end of the animations listed on http://messenger.jhuapl.edu/the_mission/ani.html , and also by clicking "animation" on http://messenger.jhuapl.edu/the_mission/gallery.html .

http://messenger.jhuapl.edu/news_room/details.php?id=197

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First Image of MESSENGER's Extended Mission!
Release Date: March 19, 2012
Topics: NAC

Date acquired: March 18, 2012
Image Mission Elapsed Time (MET): 240541431
Image ID: 1531424
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 24.41°
Center Longitude: 6.77° E
Resolution: 42 meters/pixel
Scale: This image is approximately 43 kilometers (27 miles) across
Incidence Angle: 28.95°
Emission Angle: 10.21°
Phase Angle: 29.40°

Of Interest: One year ago, MESSENGER became the first spacecraft ever to orbit Mercury. On March 18, 2012, MESSENGER completed its one-year primary mission and began a yearlong extended mission that includes a number of new scientific observation campaigns. The image shown here was acquired yesterday and is the first of MESSENGER's extended mission.

This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week.

The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the key science questions that the MESSENGER mission is addressing. During the one-year primary mission, MESSENGER acquired 88,746 images and extensive other data sets. MESSENGER is now in a yearlong extended mission, during which plans call for the acquisition of more than 80,000 additional images to support MESSENGER's science goals.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=784

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New MESSENGER Results at LPSC: Caloris Tectonic Map
Release Date: March 20, 2012
Topics: Caloris, Tectonics

Center Latitude: 31°
Center Longitude: 163° E
Scale: Caloris basin has a diameter of 1,550 kilometers (960 miles)
Reference: From abstract #1722 by Paul K. Byrne and coauthors at the 43rd Lunar and Planetary Science Conference

Of Interest: The large Caloris basin hosts a wide variety of tectonic features, including graben, ridges, and Pantheon Fossae. MESSENGER team members are in the process of mapping the tectonic features within the Caloris basin and deciphering their complicated relationships. The tectonic map shown here was published in the abstracts of the 43rd Lunar and Planetary Science Conference, which is being held this week in The Woodlands, Texas. In total, MESSENGER team members are presenting 57 papers at this conference.

The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the key science questions that the MESSENGER mission is addressing. During the one-year primary mission, MESSENGER acquired 88,746 images and extensive other data sets. MESSENGER is now in a yearlong extended mission, during which plans call for the acquisition of more than 80,000 additional images to support MESSENGER's science goals.

Credit: Byrne et al. (2012). A tectonic survey of the Caloris basin, Mercury. 43rd Lunar and Planetary Science Conference, The Woodlands, Texas, abstract #1722.

http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=783

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MESSENGER Papers Presented at the 43rd Lunar and Planetary Science Conference (57 штук)
http://messenger.jhuapl.edu/soc/lpsc2012.html

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Литосфера Меркурия похожа на апельсин с толстой коркой, заявили ученые

МОСКВА, 21 мар - РИА Новости. Внутреннее строение Меркурия оказалось достаточно необычным: планета напоминает по своей структуре апельсин с толстой кожурой - за "корочкой" из относительно тонкой коры и мантии следует гигантское железное ядро, составленное из трех отдельных слоев и занимающее примерно 80% от объема планеты, заявляют астрономы в статьях, опубликованных в журнале Science.

"У нас было свое представление о внутренней структуре Меркурия, но первоначальные наблюдения не укладывались в теории и поэтому мы усомнились в данных с зонда. Мы проверили их и поняли, что наблюдения были правильными, после чего переработали теорию под новые данные", - пояснил один из участников научной группы Дейвид Смит (David Smith) из Центра космических полетов НАСА имени Годдарда.

Первый научный коллектив под руководством Марии Зубер (Maria Zuber) из Массачусетского технологического института (США) изучил особенности строения недр Меркурия и составил карту гравитационных аномалий по данным, полученным с космического зонда "Мессенджер".

Зонд "Мессенджер" был запущен американским аэрокосмическим агентством НАСА в 2004 году. Он стал первым аппаратом, который был отправлен к Меркурию после зонда Mariner-10, пролетавшего в непосредственной близости от планеты-"вестника" 16 марта 1975 года. В марте 2011 года космический аппарат "Мессенджер" вышел на орбиту Меркурия, и проанализировал его химические и физические свойства при помощи бортовых спектрометров и высокочувствительных камер, работающих в инфракрасном и видимом диапазоне.

Вариации гравитации

Зубер и ее коллеги проанализировали данные бортовой системы радиометрии, которая вычисляла положение зонда относительно поверхности Меркурия по отклонению сигнала, поступающего с земных станций Сети дальней космической связи НАСА (DSN).

Приближение или отдаление "Мессенджера" от поверхности Меркурия позволило ученым определить, в каких точках его поверхности притяжение было относительно сильным или слабым. Эти данные были использованы для составления гравитационной карты Меркурия и определения его внутреннего строения.

По словам ученых, особо крупные аномалии им удалось обнаружить в окрестностях северного полюса планеты и в районе кратера Калорис - крупнейшего "следа" от удара астероида на поверхности Меркурия, диаметр которого составляет 1,5 тысячи километров. Ученые оценили толщину коры Меркурия, наложив "рисунок" гравитационных аномалий на топографическую карту Меркурия, составленную второй группой исследователей под руководством Ди Янь (Di Yang) из Массачусетского технологического института (США).

В своей работе Янь и его коллеги проанализировали данные, полученные другим инструментом "Мессенджера" - лазерным альтиметром MLA. Устройство представляет собой систему из лазера и чувствительных фотодатчиков. Она измеряет высоту неровностей поверхности Меркурия по задержке, с которой возвращается отраженный луч лазера на матрицу датчика.

Планета-"апельсин"

Как утверждают ученые, с момента выхода на стабильную орбиту вокруг Меркурия альтиметр успел замерить высоту 4,3 миллиона точек на поверхности планеты. В целом, Меркурий оказался достаточно "ровным" небесным телом: перепад высот на нем гораздо ниже, чем на Луне или Марсе. Кроме того, Калорис оказался очень необычным с топографической точки зрения кратером - некоторые точки в его центре расположены выше, чем края воронки. Астрономы полагают, что это указывает на существование геологической активности в недрах Меркурия уже после образования кратера.

Объединение результатов двух работ привело к неожиданным выводам - оказалось, что средняя толщина коры и мантии Меркурия составляет лишь 18% от диаметра планеты, примерно 300-400 километров.

Остальной объем Меркурия занимает ядро, которое состоит из трех частей. Самая верхняя его часть представляет собой тонкую корку из соединения железа и серы, за которой следует относительно жидкая часть из расплава железа и других элементов, занимающее 40% ядра. Самая глубокая часть образована твердым железным ядром, составляющим основную часть ядра Меркурия.

Как полагают ученые, их открытие вынудит пересмотреть все современные модели геологического устройства Меркурия, так как ни одна из них не предполагала, что планета-"вестник" похожа на апельсин с толстой кожурой.

http://ria.ru/science/20120321/602003968.html

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MESSENGER Provides New Look at Mercury's Landscape, Metallic Core, and Polar Shadows

MESSENGER completed its one-year primary mission on March 17. Since moving into orbit about Mercury a little over one year ago, the spacecraft has captured nearly 100,000 images and returned data that have revealed new information about the planet, including its topography, the structure of its core, and areas of permanent shadow at the poles that host the mysterious polar deposits.

The latest findings are presented in two papers published online in Science Express today, and in 57 papers presented this week at the 43rd Lunar and Planetary Science Conference in The Woodlands, Texas. Team members at the meeting will also preview MESSENGER's extended mission, set to run to March 2013. Presentation materials are available on the web at http://messenger.jhuapl.edu/news_room/presscon11.html.

"The first year of MESSENGER orbital observations has revealed many surprises," says MESSENGER Principal Investigator Sean C. Solomon, of the Carnegie Institution of Washington. "From Mercury's extraordinarily dynamic magnetosphere and exosphere to the unexpectedly volatile-rich composition of its surface and interior, our inner planetary neighbor is now seen to be very different from what we imagined just a few years ago. The number and diversity of new findings being presented this week to the scientific community in papers and presentations provide a striking measure of how much we have learned to date."

Mercury's Landscape

Ranging observations from MESSENGER's Mercury Laser Altimeter (MLA) have provided the first-ever precise topographic model of the planet's northern hemisphere and characterized slopes and surface roughness over a range of spatial scales. From MESSENGER's eccentric, near-polar orbit, the MLA illuminates surface areas as wide as 15 to 100 meters, spaced about 400 meters apart.

The spread in elevations is considerably smaller than those of Mars or the Moon, notes MESSENGER Co-investigator Maria T. Zuber, author of one of the papers published in Science Express. According to Zuber, of the Massachusetts Institute of Technology, the most prominent feature is an extensive area of lowlands at high northern latitudes that hosts the volcanic northern plains. Within this lowland region is a broad topographic rise that formed after the volcanic plains were emplaced.

At mid-latitudes, the interior of the Caloris impact basin -- 1,500 kilometers wide -- has been modified so that part of the basin floor now stands higher than the rim, Zuber says. "The elevated portion of the floor of Caloris appears to be part of a quasi-linear rise that extends for approximately half the planetary circumference at mid-latitudes," she writes. "Collectively, these features imply that long-wavelength changes to Mercury's topography occurred after the earliest phases of the planet's geological history."

A Surprising Core

Scientists have also come up with the first precise model of Mercury's gravity field which, when combined with the topographic data and earlier information of the planet's spin state, shed light on the planet's internal structure, the thickness of its crust, the size and state of its core, and its tectonic and thermal history.

Mercury's core is huge for the planet's size, about 85% of the planetary radius, even larger than previous estimates. The planet is sufficiently small that at one time many scientists thought the interior should have cooled to the point that the core would be solid. However, subtle dynamical motions measured from Earth-based radar combined with parameters of the gravity field, as well as observations of the magnetic field that signify an active core dynamo, indicate that Mercury's core is at least partially liquid.

"MESSENGER's observations of the gravity field have let us peer inside Mercury and get the first good look at its largest component -- the core," says Case Western Reserve University's Steven A. Hauck II, coauthor of one of the papers published in Science Express.

Scientists sought to unravel the mystery of the size and state of Mercury's core by studying its effect on long-wavelength variations in the planet's gravity field, and recent results point to a much different interior structure for Mercury from that expected.

"Mercury's core may not look like any other terrestrial planetary core," Hauck says. "The structure certainly is different from that of Earth, which has a metallic, liquid outer core sitting above a solid inner core. Mercury appears to have a solid silicate crust and mantle overlying a solid, iron sulfide outer core layer, a deeper liquid core layer, and possibly a solid inner core."

These findings will have implications for how Mercury's magnetic field is generated and for understanding how the planet evolved thermally, Hauck adds.

Polar Shadows

A chief goal of MESSENGER's primary mission was to understand the nature of the radar-bright deposits at the poles of Mercury. The leading proposal since the deposits were discovered has been that radar-bright material consists dominantly of frozen water ice.

"We've never had the imagery available before to see the surface where these radar-bright features are located," says Nancy L. Chabot, instrument scientist for MESSENGER's Mercury Dual Imaging System (MDIS) at the Johns Hopkins University Applied Physics Laboratory (APL). "MDIS images show that all the radar-bright features near Mercury's south pole are located in areas of permanent shadow, and near Mercury's north pole such deposits are also seen only in shadowed regions, results consistent with the water-ice hypothesis."

This finding is not definitive proof that those deposits are water ice, says Chabot, who is presenting her results at LPSC. And some of the radar-bright deposits are located in craters that provide thermally challenging environments to the water-ice theory. For instance, for the radar-bright material in many of the craters to be water ice would require that there be a thin layer of insulation to keep it colder than the surface, Chabot says.

But the MDIS images, combined with ongoing analysis of data from MESSENGER's Neutron Spectrometer and the MLA, will provide a more complete picture of the nature of the deposits.

Extending the Discoveries

MESSENGER's second year at Mercury will build upon these and other results from the primary mission phase, emphasizes MESSENGER Project Scientist Ralph L. McNutt Jr., of APL. "The second year of orbital operations will not be a simple continuation of the primary mission," he says. "Extended mission themes will include more comprehensive measurement of the magnetosphere and exosphere during a period of more active Sun, greater focus on observations at low spacecraft altitudes, and a greater variety of targeted observations."

"MESSENGER has already fundamentally changed our view of this innermost planet," he adds. "With the extension of the MESSENGER mission, many more discoveries can be expected."

http://messenger.jhuapl.edu/news_room/details.php?id=198

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Mercury's Interior: So Different from Earth!
http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1&gallery_id=2&image_id=787

[Александр Ч.]

Тут воду, возможно, на Меркурии нашли, а на форуме тишина... :?:

Radar-bright Deposits near Mercury's North Pole

The highest-resolution radar image of Mercury's north polar region made from the Arecibo Observatory (Harmon et al., Icarus, 211, 37-50, 2011) is shown in yellow on a mosaic of MESSENGER orbital images. Radar-bright features in the Arecibo image all collocate with areas mapped as in shadow in Mercury Dual Imaging System (MDIS) images to date, consistent with the proposal that radar-bright materials contain water ice. This image is shown in a polar stereographic projection with every 5° of latitude and 30° of longitude indicated and with 0° longitude at the bottom. On Mercury, 5° of latitude is approximately 213 km.

http://www.nasa.gov/mission_pages/messenger/multimedia/messenger_orbit_image20120322_3.html

[Shwed]

надо туда посадочный модуль отправить.

[Имxотеп]

Тут воду, возможно, на Меркурии нашли, а на форуме тишина... :?:
http://www.nasa.gov/mission_pages/messenger/multimedia/messenger_orbit_image20120322_3.html

Что там нашли - дело мутное. Да и было уже, вернитесь на страницу назад.

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Обнаружен спутник Меркурия!

Date acquired: March 31, 2012
Image Mission Elapsed Time (MET): 131766564
Image ID: 6418
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 38.15°
Center Longitude: 66.18°
Resolution: 410 meters/pixel (0.25 miles/pixel) in the lower left corner of the image
Scale: The large crater in the center of the image (Copland) is about 210 kilometers (130 miles) in diameter.
Spacecraft Altitude: 16,200 kilometers (10,070 miles)
Incidence Angle: 69.1°
Emission Angle: 80.8°
Phase Angle: 138.2°

Of Interest: This discovery image provides the first evidence that Mercury has a small natural satellite or moon. Visible as a small bright spot in an image taken yesterday by the Mercury Dual Imaging System (MDIS) Wide Angle Camera (WAC), the moon is approximately 70 meters (230 feet) in diameter and orbits Mercury at a mean distance of 14,300 km (8,890 miles). A proposal to name the moon "Caduceus," after the staff carried by the Roman god Mercury, has been submitted by the MESSENGER team to the International Astronomical Union, the body responsible for assigning names to celestial objects.

This discovery presents an unprecedented opportunity for a return of samples from the Mercury system, as Project Scientist Nat MacRulf explains. "We have yet to identify a sample from Mercury in any of the meteorite collections we have here on Earth. Such a sample would give us critical insight into the chemical composition of Mercury and the timing of crustal formation on that body, leading to a better understanding of how the planet formed and evolved. If we could obtain a sample of Caduceus, it would enhance the scientific return of the MESSENGER mission beyond our wildest dreams!"

Work on designing a scenario for sample return is already underway. MESSENGER Project Manager Burt Panini held an emergency meeting with the MESSENGER mission operations and navigation teams yesterday evening to determine if the spacecraft could be targeted toward the diminutive moon. After an intensive discussion, a unanimous decision was taken to abandon the orbit-correction maneuvers that had been planned for later this month to place the spacecraft in an eight-hour orbit. Instead, the new plan is to use the remaining propellant to crash MESSENGER into Caduceus. "Our detailed analysis tells us that if we act now, and with the right trajectory, MESSENGER will impart just enough momentum to the moon to break it free of Mercury's gravity well and set it on an Earth-crossing trajectory suitable for recovery as a Mercury meteorite", said Panini.

This action will form the basis of a new request to NASA by the MESSENGER team for an extended extended mission, tentatively called "MESSENGER Infinitesimally Nudging Caduceus," or MIN-C for short. Once MIN-C is approved by NASA, the spacecraft will be targeted for a collision trajectory. If Caduceus is successfully released from the pull of Mercury and placed on a course to reach Earth, we can expect the moon to arrive at Earth by 2014. "The risk to the public is reassuringly small", offers MESSENGER mission design lead Adam McJames. "We have designed a trajectory that will bring the moon to Earth at a remote location on the Wilkes Land ice sheet in Antarctica. This trajectory will avoid all population centers and will put the moon's impact site within reach for retrieval by the scientific staff at the U.S.-operated McMurdo Station."

If successful, MESSENGER's extended extended MIN-C mission will mark the first instance of the documented arrival to Earth of material from the Mercury system. Moreover, it will serve as the basis for a new Discovery-class mission proposal currently in development by the Applied Psychics Laboratory for a Mercury lander mission for in situ X-ray analysis of surface composition. That mission is to be named the Hermean On-surface Analysis with X-rays.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

[Леонардо]

Причем брат-близнец астероида Ида. Удивительная вещь!!!

[pkl]

Отмечаем 1-е апреля? :wink:

[Reader]

Отмечаем 1-е апреля? :wink:

Если 31 марта на: http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=811 , шутили, то - не по петросяновски, слишком уж тонко

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Release Date: April 1, 2012

[Reader]

А вообще, баллистически (с учётом близрасположенного Солнца, сильно возмущающего орбиту такового) - естественный спутник Меркурия, видимо, невозможен - да?