OSIRIS-Rex – Atlas V 411 (AV-067) – Canaveral SLC-41 – 08.09.2016 23:05 UTC

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https://www.asteroidmission.org/nightingalerecona/

Nightingale during Reconnaissance A

This is the highest-resolution image captured of candidate sample site Nightingale as of October 26. Site Nightingale is located near asteroid Bennu's north pole. The crater's center is visible in the top center of the image, which contains an accumulation of smaller rocks. The image was taken by the PolyCam camera on NASA's OSIRIS-REx spacecraft on October 26, from a distance of 0.6 miles (1 km). The field of view is 47 ft (14.4 m). For reference, the light-colored boulder (far left center) is 5 ft (1.4 m) long, which is about the length of a bicycle. The image was obtained during the mission's Reconnaissance A phase. When the image was taken, the spacecraft was over the northern hemisphere, pointing PolyCam north and to the west.

Date Taken: October 26, 2019

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona

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 NASA's OSIRIS-REx‏ @OSIRISREx 34 мин. назад

The Asteroid Science in the Age of Hayabusa2 and OSIRIS-REx workshop will conclude with talks on rubble-pile asteroids, altered asteroids, primitive asteroids, and sample analysis

If you're there, share some science highlights with us!
#SpinningTop2019

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NASA's OSIRIS-REx‏ @OSIRISREx 3 ч. назад

Bennu's surface is full of similar looking rocks and grey material, so sometimes it's difficult to spot a sample site in an image. To make it easier, the team looks for the site's recognizable features. These features also help determine things like direction and location.




3 ч. назад

One of site Sandpiper's most recognizable features is this large, bright boulder, which has a fracture running through it. The boulder is 16 ft (5 m) wide, which is about the size of a box truck. The site is just above the boulder... get a better look here:
http://bit.ly/32Dgi6o

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NASA's OSIRIS-REx @OSIRISREx 38 мин. назад

Osprey's recognizable features may be the most distinct of all 4 sample sites. There is a dark patch of material in the crater's center and a large, flat boulder that sits on the northern wall (making it easy to determine which way is north).




37 мин. назад

This boulder is colloquially called the "12 o'clock rock" by the team. It is 16 ft (4.8 m) long, which is about the length of compact SUV.   See site Osprey from all angles: https://bit.ly/2XbF78c

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NASA's OSIRIS-REx‏ @OSIRISREx 20 мин. назад

Site Kingfisher is tricky to pinpoint in an image like this.




20 мин. назад

Look for the "Mickey Mouse ears"   The site itself is in the large crater, but the two neighboring craters are helpful markers. One "ear" is south of the crater, and the other is west. The southern crater is 9 ft (2.7 m) across, which is about the width of a parking space.

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NASA's OSIRIS-REx @OSIRISREx 4 мин. назад

Nightingale is pretty easy to recognize because of its dark regolith.  Try finding the site in these images: http://bit.ly/2NPHhHH




4 мин. назад

If you're not entirely sure, the "mountain" on the crater's northern rim is an absolute giveaway. The site is in the clear area, left of the boulder.  From the bottom of the crater, this jumbo-size boulder measures 33 ft (10 m) tall, about the height of a three-story building.

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NASA's OSIRIS-REx‏ @OSIRISREx 2 ч. назад

Candidate sample collection sites Nightingale, Kingfisher, Osprey, and Sandpiper are located in various nooks and crannies around Bennu.

Because the sites are geographically diverse they each have a unique topography.

Ready for some close-up, 3D views of each site's terrain?




2 ч. назад

Here's a 3D printed Digital Terrain Model (DTM) of site Sandpiper. The crater's steep slopes stand out, along with the ruggedness of Bennu's southern hemisphere where Sandpiper is located.




2 ч. назад

The crater is 206 ft (63 m) in diameter, which is about the length of the Lincoln Memorial.

https://www.asteroidmission.org/candidate-sample-sites/sandpiper/

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 NASA's OSIRIS-REx‏ @OSIRISREx 2 мин. назад

Site Osprey is situated right in the middle of this Digital Terrain Model (DTM). The DTM showcases Osprey's "12 o'clock rock" and the crater floor's topography. The crater is 66 ft (20 m) in diameter, which is about the length of a bowling lane.

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NASA's OSIRIS-REx‏ @OSIRISREx 33 мин. назад

Looking at this Digital Terrain Model (DTM), you can see the small crater where site Kingfisher is located (lower left). The DTM reveals the crater's gradual slopes, along with the height of surrounding boulders.




33 мин. назад

The crater has a diameter of 26 ft (8 m), which is about the length of a dump truck.

Stroll through Kingfisher's terrain: https://bit.ly/2OAUKT0

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NASA's OSIRIS-REx @OSIRISREx 27 мин. назад

Located in the center of this Digital Terrain Model (DTM) is site Nightingale. The DTM shows the steep slopes on the crater's northern wall and the large boulders perched on the rim.




27 мин. назад

The building-size boulder on the crater's eastern rim is 43 ft (13 m) across, about the length of a school bus.

Hike around Nightingale's terrain: https://bit.ly/2D5mAkJ

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NASA's OSIRIS-REx @OSIRISREx 2 ч. назад

The team is in the midst of selecting the final primary and backup sample collection sites! Each site has its particular perks — and its own obstacles. The team is mulling over all of these as they make their decision.  So... how's Sandpiper looking?  https://bit.ly/2OaVfnr

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Surprises from Asteroid Bennu

NASA Goddard

2 дек. 2019 г.

The OSIRIS-REx team has already pushed the boundaries of scientific exploration -- going from ground-based radar images from Arecibo in Puerto Rico all the way to orbiting a few hundred meters from asteroid Bennu. The team is mere months away from a sample collection attempt at the asteroid surface. Before this attempt, we take a look back at some of the major achievements, surprises and challenges of sampling an asteroid with OSIRIS-REx.

https://www.youtube.com/embed/rhBaNTEzNHg?feature=oembed (2:19)

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https://www.asteroidmission.org/?latest-news=nasas-osiris-rex-mission-explains-bennus-mysterious-particle-events

NASA's OSIRIS-REx Mission Explains Bennu's Mysterious Particle Events

December 4, 2019 - Shortly after NASA's OSIRIS-REx spacecraft arrived at asteroid Bennu, an unexpected discovery by the mission's science team revealed that the asteroid could be active, or consistently discharging particles into space. The ongoing examination of Bennu – and its sample that will eventually be returned to Earth – could potentially shed light on why this intriguing phenomenon is occurring.


This view of asteroid Bennu ejecting particles fr om its surface on January 6 was created by combining two images taken by the NavCam 1 imager onboard NASA's OSIRIS-REx spacecraft: a short exposure image (1.4 ms), which shows the asteroid clearly, and a long exposure image (5 sec), which shows the particles clearly. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

The OSIRIS-REx team first observed a particle ejection event in images captured by the spacecraft's navigation cameras taken on Jan. 6, just a week after the spacecraft entered its first orbit around Bennu. At first glance, the particles appeared to be stars behind the asteroid, but on closer examination, the team realized that the asteroid was ejecting material fr om its surface. After concluding that these particles did not compromise the spacecraft's safety, the mission began dedicated observations in order to fully document the activity.

"Among Bennu's many surprises, the particle ejections sparked our curiosity, and we've spent the last several months investigating this mystery," said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. "This is a great opportunity to expand our knowledge of how asteroids behave."

After studying the results of the observations, the mission team released their findings in a Science paper published Dec. 6. The team observed the three largest particle ejection events on Jan. 6 and 19, and Feb. 11, and concluded that the events originated from different locations on Bennu's surface. The first event originated in the southern hemisphere, and the second and third events occurred near the equator. All three events took place in the late afternoon on Bennu.

The team found that, after ejection from the asteroid's surface, the particles either briefly orbited Bennu and fell back to its surface or escaped from Bennu into space. The observed particles traveled up to 10 feet (3 meters) per second, and measured from smaller than an inch up to 4 inches (10 cm) in size. Approximately 200 particles were observed during the largest event, which took place on Jan. 6.

The team investigated a wide variety of possible mechanisms that may have caused the ejection events, and narrowed the list to three candidates: meteoroid impacts, thermal stress fracturing, and released of water vapor.

Meteoroid impacts are common in the deep space neighborhood of Bennu, and it is possible that these small fragments of space rock could be hitting Bennu wh ere OSIRIS-REx is not observing it, shaking loose particles with the momentum of their impact.

The team also determined that thermal fracturing is another reasonable explanation. Bennu's surface temperatures vary drastically over its 4.3-hour rotation period.


This animation illustrates the modeled trajectories of particles that were ejected from Bennu's surface on January 19. After ejecting from the asteroid's surface, the particles either briefly orbited Bennu and fell back to its surface or escaped away from Bennu and into space. Credit: NASA/Goddard/University of Arizona/Lauretta & Hergenrother et al., Science 10.1126

Although it is extremely cold during the night hours, the asteroid's surface warms significantly in the mid-afternoon, which is when the three major events occurred. As a result of this temperature change, rocks may begin to crack and break down, and eventually particles could be ejected from the surface. This cycle is known as thermal stress fracturing.

Water release may also explain the asteroid's activity. When Bennu's water-locked clays are heated, the water could begin to release and create pressure. It is possible that as pressure builds in cracks and pores in boulders wh ere absorbed water is released, the surface could become agitated, causing particles to erupt.

But nature does not always allow for simple explanations. "It could be that more than one of these possible mechanisms are at play," said Steve Chesley, an author on the paper and Senior Research Scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "For example, thermal fracturing could be chopping the surface material into small pieces, making it far easier for meteoroid impacts to launch pebbles into space."

If thermal fracturing, meteoroid impacts, or both, are in fact the causes of these ejection events, then this phenomenon is likely happening on all small asteroids, as they all experience these mechanisms. However, if water release is the cause of these ejection events, then this phenomenon would be specific to asteroids that contain water-bearing minerals, like Bennu.

Bennu's activity presents larger opportunities once a sample is collected and returned to Earth for study. Many of the ejected particles are small enough to be collected by the spacecraft's sampling mechanism, meaning that the returned sample may possibly contain some material that was ejected and returned to Bennu's surface. Determining that a particular particle had been ejected and returned to Bennu might be a scientific feat similar to finding a needle in a haystack. The material returned to Earth from Bennu, however, will almost certainly increase our understanding of asteroids and the ways they are both different and similar, even as the particle ejection phenomenon continues to be a mystery whose clues we'll also return home with in the form of data and further material for study.[

Sample collection is scheduled for summer 2020, and the sample will be delivered to Earth in September 2023.

NASA's Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission's science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA's New Frontiers Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama, for the agency's Science Mission Directorate in Washington.

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https://nauka.tass.ru/nauka/7283381

6 ДЕК, 15:39
Зонд NASA проследил за выбросами пыли с поверхности астероида Бенну
Оказалось, что в космос выбрасываются не только небольшие частицы, но и достаточно крупные пылинки

ТАСС, 6 декабря. Камеры и другие научные приборы зонда OSIRIS-REx зафиксировали несколько повторных выбросов пыли с поверхности астероида Бенну. Часть из которых смогла "оторваться" от притяжения этого небесного тела и достичь открытого космоса. Снимки и замеры межпланетной станции ученые NASA опубликовали в научном журнале Science.

"Мы открыли множество сюрпризов на поверхности Бенну, однако эти загадочные фонтаны частиц заинтересовали нас особенно сильно. На то, чтобы изучить загадку их формирования, мы потратили несколько последних месяцев. Для нас это была отличная возможность расширить представления о том, как ведут себя астероиды", - рассказал руководитель миссии Данте Лауретта.

Зонд OSIRIS-REx запустили в сентябре 2016 года в рамках миссии по сближению и сбору образцов с поверхности астероида Бенну (1999 RQ36). В недавнем прошлом этот астероид считали одной из угроз для существования жизни на нашей планете. Аппарат достиг небесного тела в начале декабря прошлого года и передал первые фотографии Бенну.

Оказалось, что этот астероид по форме и окраске очень похож на еще одно небесное тело, астероид Рюгю, который на протяжении последних полутора лет изучала японская миссия "Хаябуса-2". В отличие от сухого и безводного Рюгю, в породах Бенну астрономы нашли рекордные количества воды, что сделало его еще более интересным объектом с точки зрения изучения процесса формирования Солнечной системы.

Пыль космоса

В первых числах января этого года, как отмечает Лауретта, практически сразу после сближения с Бенну, навигационные камеры OSIRIS-REx зафиксировали очень странный феномен - с поверхности астероида в космос били своеобразные "фонтаны" из пыли, которые состояли из нескольких сотен частиц. Когда ученые убедились в том, что эти выбросы не угрожали работе зонда, они потратили несколько месяцев на их изучение.

Наблюдения подтвердили, что подобные "извержения" пыли действительно происходят достаточно часто. При этом новые данные заставили ученых усомниться в том, что они понимают, как именно возникают эти "фонтаны". В частности, Лауретта и его коллеги обнаружили, что в космос выбрасываются не только небольшие пылинки, но и достаточно крупные куски "космической гальки" диаметром в сантиметр и более.

Вдобавок сила этих выбросов оказалась такой, что значительная часть пыли разогналась до скоростей, которые позволили ей преодолеть притяжение Бенну и улететь в открытой космос. Это означает, что далеко не все астероиды являются "безжизненными" небесными телами, чья поверхность не меняется сама по себе.

Ученые пока не могут сказать, что стало причиной появления этих выбросов,так как два их главных источника - превращение поверхностных слоев льда в пар и центробежные силы - не должны работать на Бенну. По мнению Лауретты и его команды, на роль их источника примерно в равной степени претендуют падения микрометеоритов, а также процессы внутри недр самого астероида, которые связаны с запасами воды в его недрах или формированием трещин в булыжниках на поверхности под действием тепла и света Солнца.

Сейчас OSIRIS-REx заканчивает составление карты поверхности Бенну, после чего Лауретта и его коллеги выберут место, откуда будет взят образец вещества массой около 60 грамм. NASA планирует провести эту процедуру ориентировочно в середине лета 2020 года, если этому не помешают булыжники, которыми усеяна поверхность Бенну. После забора грунта OSIRIS-REx запустит капсулу с первичной материей Солнечной системы в сторону Земли. Если все пройдет удачно, она упадет на территории американского штата Юта в конце сентября 2023 года.

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 NASA's OSIRIS-REx‏ @OSIRISREx 9 ч. назад

Which site will it be? Follow #XMarksTheSpot tomorrow to find out!  Tune in at 1:00 pm EST for the announcement: https://bit.ly/38tt1fP 

youtube.com/watch?v=McrbVABVGhc

Начало трансляции в 21:00 ДМВ

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