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OSIRIS-REx
 
https://nplus1.ru/news/2019/03/14/seismic-stars
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Астрономы заметили ускорение вращения астероида Бенну

Анимация вращения Бенну, смонтированная из снимков, полученных камерой MapCam 4 декабря 2018 года перед первым пролетом OSIRIS-REx над северным полюсом астероида.
NASA/Goddard/University of Arizona

Астрономы обнаружили, что период вращения астероида Бенну, который сейчас изучает межпланетная станция OSIRIS-REx, сокращается примерно на одну секунду каждые сто лет. Это может привести к его разрушению через несколько миллионов лет, а за процесс ускорения, по мнению ученых, ответственен YORP-эффект.  Статья опубликована в журнале Geophysical Research Letters.
500-метровый околоземный астероид (101955) Бенну является представителем углеродных астероидов спектрального класса В. Изучение подобных объектов может дать важную информацию о формировании и эволюции Солнечной системы, кроме того, считается, что богатые углеродом астероиды, такие как Бенну, могут быть ответственны за поставку аминокислот и воды на молодую Землю. Бенну был выбран в качестве цели для автоматической межпланетной станции OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer), которая в настоящее время изучает его с орбиты. В начале июля 2020 года станция сблизится с поверхностью астероида и соберет с нее при помощи специального манипулятора 60 граммов пыли и фрагментов породы, после чего, в марте 2021 года, космический аппарат отправится к Земле и сбросит в атмосферу капсулу с грунтом в сентябре 2023 года.

В новой работе группа астрономов во главе с Майком Ноланом (Mike Nolan) изучала, как изменяется скорость вращения астероида со временем. Для этой цели ученые проанализировали данные наземных наблюдений за Бенну, проводившихся в 1999 и 2005 годах, а также данные за 2012 год, полученные космическим телескопом «Хаббл» и новые результаты, полученные OSIRIS-REx. Оказалось, что период вращения Бенну сокращается примерно на одну секунду каждые сто лет, это может привести к тому, что в течение нескольких миллионов лет скорость вращения астероида вырастет достаточно сильно для того, чтобы начался процесс его разрушения. Сейчас, по данным OSIRIS-REx, Бенну совершает один оборот вокруг своей оси за 4,3 часа.
Существует несколько гипотез, объясняющих изменение скорости вращения, такие как изменение момента инерции из-за столкновения с другим объектом или потерей массы в результате различных процессов. Однако наиболее вероятным механизмом ускорения, которое наблюдалось у других околоземных астероидах, начиная с (54509) YORP, является эффект Ярковского — О'Кифа — Радзиевского — Пэддэка, заключающийся в изменении скорости вращения астероида ассиметричной формы под действием солнечного излучения. Правильность этой идеи должен подтвердить OSIRIS-REx на основании дальнейших наблюдений, в ходе которых он определит точную форму астероида, тепловые свойства поверхности и распределение силы тяжести вблизи нее.
Еще одна действующая миссия по доставке грунта с астероида — автоматическая станция «Хаябуса-2». Зонд 27 июня 2018 года прибыл к своей цели — астероиду 162173 Ryugu, который принадлежит к наиболее распространенному типу астероидов — классу С. Изучение химических свойств его вещества позволит ученым судить о составе протосолнечной туманности.
Александр Войтюк
 
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3D Shape Model of Asteroid Bennu

NEW HORIZONS v2.0

Опубликовано: 20 мар. 2019 г.

Credit: NASA/Goddard/University of Arizona/Roman Tkachenko
https://www.youtube.com/watch?v=udoaJty0rjQ (0:20)
 
https://www.nasa.gov/image-feature/goddard/2019/bennu-in-stereo
Цитата
March 27, 2019

Bennu in Stereo



This set of stereoscopic images provides a 3D view of the large, 170-foot (52-meter) boulder that juts from asteroid Bennu’s southern hemisphere and the rocky slopes that surround it. The stereo pair was created by stereo image processing scientists Dr. Brian May, who is also the lead guitarist for the rock band Queen, and Claudia Manzoni. In January, May and Manzoni formally joined NASA’s OSIRIS-REx mission science team as collaborators to create stereoscopic data products, which will be used by the team while selecting a sample collection site on Bennu.

“I’m proud to have been adopted as a collaborator on the OSIRIS-REx team, along with my colleague Claudia Manzoni,” said May. “Our passion is producing stereoscopic (3-D) images from the astounding data that the OSIRIS-REx mission has been collecting.”

The two images in this stereo pair were taken from slightly different viewpoints, with one of the images meant for the left eye and the other for the right. The two images are then combined by the brain to give the perception of depth. To see the pair in 3D, cross your eyes and relax your vision until there are three images, then focus on the center image. Tilt your head as needed to bring the image into focus. A version of the image suitable for viewing through a stereoscope can be found here.

The cropped and processed images were obtained on December 1 and 2, 2018, by the PolyCam camera during the spacecraft’s final approach toward the asteroid.

Credit: NASA/Goddard/University of Arizona

Last Updated: March 27, 2019
Editor: Karl Hille
 
https://www.asteroidmission.org/updated-bennu-shape-model-3d-files/
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75-CENTIMETER SHAPE MODEL (MAR. 2019)

After studying asteroid Bennu at close range for three months, the OSIRIS-REx mission team has developed a new shape model with a 75-centimeter resolution. This more precise model, which was created using imagery taken by OSIRIS-REx’s PolyCam camera, shows features on Bennu smaller than one meter.



Credit: NASA/Goddard/University of Arizona
OBJ FILE
STL FILE
 
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NASA's OSIRIS-REx‏Подлинная учетная запись @OSIRISREx 41 мин. назад

This week I'm gearing up for Flyby 5 of Detailed Survey: Baseball Diamond phase. On Thurs., I'll be flying north to south, imaging Bennu with PolyCam, OLA and OTES from a distance of 1.9 - 3.1 miles (3.1 - 5 km).

More on my whereabouts: http://bit.ly/WhereIsOREX

 
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NASA's OSIRIS-REx‏Подлинная учетная запись @OSIRISREx 10 мин. назад

Somewhere on this rock - in one of these views - is the spot that will ultimately be chosen as our sample collection location. The OSIRIS-REx sample site selection campaign is in full swing! Get the downloadable graphic here: https://bit.ly/2FLRvnf
https://bit.ly/2FLRvnf --> https://www.asteroidmission.org/bennu-sides-and-global-mosaic/
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Four Sides of Bennu with Corresponding Global Mosaic

This image shows four views of asteroid Bennu along with a corresponding global mosaic. The images were taken on Dec. 2, 2018, by the OSIRIS-REx spacecraft’s PolyCam camera.

Date Taken: Dec. 2, 2018

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona
 
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OSIRIS-REx: Orbiting Asteroid Bennu

NASA Video

Опубликовано: 3 апр. 2019 г.

Olivia Billett, OSIRIS-REx spacecraft science lead at Lockheed Martin, talks about the complexities of orbiting around asteroid Bennu.

The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft launched Sept. 8, 2016, and began orbiting asteroid Bennu on Dec. 31, 2018. Its primary science objective is to study Bennu and collect a sample for return to Earth in 2023. Bennu is a carbon-rich asteroid that records the earliest history of our solar system, and which may contain the raw ingredients of life.
https://www.youtube.com/watch?v=ukbgNGwrO4M (0:37)
 
https://www.nasa.gov/image-feature/goddard/2019/osiris-rex-captures-laser-3d-view-of-bennu
Цитата
April 4, 2019

OSIRIS-REx Captures Laser 3D View of Bennu



This three-dimensional view of asteroid Bennu was created by the OSIRIS-REx Laser Altimeter (OLA), contributed by the Canadian Space Agency, on NASA’s OSIRIS-REx spacecraft. From Feb. 12 through 17, OLA made more than 11 million measurements of the distance between OSIRIS-REx and Bennu’s surface as the spacecraft flew less than 1.2 miles (2 km) above the surface – the closest orbit ever achieved by spacecraft. OLA obtained these measurements by firing laser pulses at Bennu and measuring the amount of time it takes for the light to bounce off the asteroid’s surface and return to the instrument. That time measurement is then translated into altitude data. Using this data, the OLA team created the 3-D model of Bennu’s surface. The colors represent the distance from the center of Bennu: dark blue areas lie approximately 197 feet (60 meters) lower than peaks indicated in red. Some parts of the asteroid have not yet been measured, which creates gaps in the image. OLA will take nearly a billion more measurements throughout 2019 to complete the first-ever high-resolution 3D lidar map of a near-Earth asteroid.

Credit: NASA/University of Arizona/CSA/York/MDA

Last Updated: April 4, 2019
Editor: Karl Hille
 
https://www.asteroidmission.org/20190329-fb4-equator-view/
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Bennu’s Equatorial Ridge

On March 29, the PolyCam camera on NASA’s OSIRIS-REx spacecraft took this image of a region of dark regolith on asteroid Bennu. When the image was taken, the spacecraft was positioned over Bennu’s northern hemisphere, looking southward over the asteroid’s equatorial bulge. The field of view shown is 168 ft (51.2 m) wide. For scale, the bright, rectangular rock above the dark region is 8 ft (2.4 m) wide, about the size of a long bed on a pickup truck. This image was taken during Flyby 4 of the mission’s Detailed Survey: Baseball Diamond phase.

Date Taken: Mar. 29, 2019

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona
 
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NASA's OSIRIS-REx‏Подлинная учетная запись @OSIRISREx 3 ч. назад

This week is Flyby 6 A&B of Detailed Survey: Baseball Diamond phase. On Thurs. and Fri., I'll be flying south to north, imaging Bennu with PolyCam, OLA and OTES from a distance of 1.9 - 3.1 miles (3.1 - 5 km). For more on this week's ops plan: https://bit.ly/2U5MniW

 
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NASA's OSIRIS-REx‏Подлинная учетная запись @OSIRISREx 5 мин. назад

So we're clear, that rock was like that when I got here ...

This image from DS:BBD Flyby 1 shows the rocky surface of Bennu just south of the equator. That cracked rock is 69 ft long, about the length of 4 parallel parking spots.

More detail: https://bit.ly/2IpIKSG
https://www.asteroidmission.org/20190307-polycam-cracked-rock/
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Rocks and Boulders near Bennu’s Equator

This image shows the rocky surface of Bennu in a region just south of the asteroid’s equator. The PolyCam camera on NASA’s OSIRIS-REx spacecraft took the image on March 7 from a distance of 3 miles (4.8 km). The width of the field of view is 185 ft (56.4 m) of Bennu’s surface. For scale, the cracked rock at the top of the image is 69 ft (21 m) long, which is about the length of four parallel parking spots. The image was obtained during Flyby 1 of the mission’s Detailed Survey: Baseball Diamond phase.

Date Taken: Mar. 7, 2019

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona
 
https://www.asteroidmission.org/20190307-polycam-northern-boulder/
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Northern Boulder Imaged by PolyCam

This image shows one of the largest boulders on asteroid Bennu’s northern hemisphere. It was taken on March 7 by the PolyCam camera on NASA’s OSIRIS-REx spacecraft from a distance of 2.9 miles (4.6 km). The field of view in the image is 191 feet (58.2 meters) and the boulder itself measures 77 feet (23.5 meters) on its longest dimension, which is about the same length as one-fourth of an American football field.

The image was obtained during Flyby 1 of the mission’s Detailed Survey: Baseball Diamond phase while the spacecraft was flying over Bennu’s equator and pointing PolyCam to the north and west of the asteroid.

Date Taken: March 7, 2019

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona
 
https://www.asteroidmission.org/20190307-southern-boulder-region/
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20190307 Southern Boulder Region

This image shows a region in the southern hemisphere of asteroid Bennu that contains a large population of boulders. The PolyCam camera on NASA’s OSIRIS-REx spacecraft took the image on March 7 from a distance of 3 miles (4.8 km). The field of view for the image is 190 ft (58 m) wide. For scale, the smaller, smooth, rectangular boulder on the left is 40 ft (12.1 m) across, which is about the length of a standard telephone pole. The image was obtained during Flyby 1 of the mission’s Detailed Survey: Baseball Diamond phase. When the image was taken, the spacecraft was over the equator, pointing PolyCam to the south and east.

Date Taken: Mar. 7, 2019

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona
 
https://www.asteroidmission.org/20190307-polycam-benben/
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Bennu’s Boulder No. 1 Imaged by PolyCam

This image shows a portion of the largest boulder on Bennu, located in the southern hemisphere. The PolyCam camera on NASA’s OSIRIS-REx spacecraft took the image on March 7 from a distance of 3 miles (4.8 km). The field of view for the image is 191 ft (58.2 m) wide. For scale, the shiny rectangular rock just to the north of the boulder is about 5 ft (1.5 m) wide, which is about the length of a bicycle. The image was obtained during Flyby 1 of the mission’s Detailed Survey: Baseball Diamond phase. When the image was taken, the spacecraft was over the equator, pointing PolyCam to the south and west.

Date Taken: March 7, 2019

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona
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NASA's OSIRIS-REx‏Подлинная учетная запись @OSIRISREx 8 ч. назад

This is the last week of Detailed Survey: Baseball Diamond phase. On Thursday and Friday, Flyby 7 executes. I'll be running a north/south pass, observing Bennu at +/-40° latitude with the MapCam, OLA and OTES instruments.
 
https://www.asteroidmission.org/20190314-mapcam-southern-limb-and-crater/
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Bennu’s Southern Limb and Large Crater

This image shows asteroid Bennu’s south pole and a large crater in the southern hemisphere. It was taken by the MapCam camera on NASA’s OSIRIS-REx spacecraft on March 14 from a distance of 2.2 miles (3.6 km). The field of view is 847 ft (258 m) wide. For scale, the light-colored, rectangular rock at the top of the image is 27 ft (8.3 m) wide, which is the width of a tennis court. The spacecraft obtained the image during Flyby 2 of the mission’s Detailed Survey: Baseball Diamond phase by pointing the camera to the south while flying over the equator.

Date Taken: March 14, 2019

Instrument Used: OCAMS (MapCam)

Credit: NASA/Goddard/University of Arizona
 
крупненько 20190329-FB4-Equator-View, кроп
вот отсюда
push the human race forward
 
https://www.asteroidmission.org/20190314-mapcam-eastern-limb-and-boulders/
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Boulders on Bennu’s Eastern Limb

This image provides a view of the region around Bennu’s equator. It was taken by the MapCam camera on NASA’s OSIRIS-REx spacecraft on March 14 from a distance of 2.2 miles (3.6 km). The field of view is 837 ft (255 m) wide. The large, protruding boulder near the center of the image is 115 ft (35 m) wide, which is about the length of two boxcars. The spacecraft obtained the image during Flyby 2 of the mission’s Detailed Survey: Baseball Diamond phase by pointing the camera to the east while flying over Bennu’s equator.

Date Taken: March 14, 2019

Instrument Used: OCAMS (MapCam)

Credit: NASA/Goddard/University of Arizona
 
https://www.asteroidmission.org/20190314-mapcam-boulders-benben-and-limb/
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Southern View of Bennu from the Equator

This image shows a view of asteroid Bennu from the equator, looking south toward the largest boulder on the asteroid and then off into space. It was taken by the MapCam camera on NASA’s OSIRIS-REx spacecraft on March 14 from a distance of 2.2 miles (3.6 km). The field of view is 830 ft (253 m) wide. For scale, the light-colored rock just below the center of the image is 36 ft (11 m) wide, which is about the same length as a telephone pole. The spacecraft obtained the image during Flyby 2 of the mission’s Detailed Survey: Baseball Diamond phase.

Date Taken: March 14, 2019

Instrument Used: OCAMS (MapCam)

Credit: NASA/Goddard/University of Arizona
 
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NASA's OSIRIS-REx‏Подлинная учетная запись @OSIRISREx 2 ч. назад

This week is the beginning of a new mission phase - Detailed Survey: Equatorial Stations. This phase is designed to obtain the observations needed to hone in on the best sample collection site.




NASA's OSIRIS-REx‏Подлинная учетная запись @OSIRISREx 2 ч. назад

Over the next 7 weeks, I'll be making north/south slews on 7 different stations around Bennu in order to get observations from different sun illumination conditions. More details on my operations during Detailed Survey: Equatorial Stations: https://bit.ly/2VhJMqx

 
https://www.asteroidmission.org/20190321-polycam-boulder-field/
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Detail of Boulder Field on Bennu

This image shows a region in the southern hemisphere of asteroid Bennu that contains a mix of large and small boulders. The PolyCam camera on NASA’s OSIRIS-REx spacecraft took the image on March 21 from a distance of 2.2 miles (3.5 km). The field of view is 160 ft (49 m). For scale, the large boulder in the upper half the image is 82 ft (25 m) wide, which is a little less than the distance between bases on a baseball diamond. The image was obtained during Flyby 3 of the mission’s Detailed Survey: Baseball Diamond phase. When the image was taken, the spacecraft was over the equator, pointing PolyCam toward the south of the asteroid.

Date Taken: March 21, 2019

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona
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