Deep Impact !

[sol]

Никто не подскажет ссылку на ролик со схематическим вращением этой кегли?

Особо интересует центробежная сила на "экваторе" кометы. В смысле - могут ли там быть области с отрицательным весом, когда центробежная сила превышает силу тяжести....

[instml]

Астрономы обнаружили каменистую планету микролинзированием

Астрофизики впервые обнаружили удаленную от своей звезды каменистую планету методом гравитационного микролинзирования. Препринт статьи доступен на сайте arXiv.org.

...........

Анализ изменений блеска позволил ученым установить, что масса планеты составляет около 10 земных, а радиус орбиты - около 3,2 астрономических единиц (1 астрономическая единица равна среднему расстоянию от Земли до Солнца). Период обращения вокруг собственного светила у новой планеты составляет, в свою очередь, 7,6 земных лет.

По словам ученых, новые результаты хорошо согласуются с современными теориями формирования планет. Так, в частности, обнаруженная экзопланета является неудавшимся газовым гигантом. Кроме этого, по мнению исследователей, результаты наблюдений показывают, что для регистрации планет методом гравитационного микролинзирования может использоваться Deep Impact, который сейчас находится на гелиоцентрической орбите после встречи с кометой Хартли 2 в ноябре 2010 года. Новая миссия аппарата пока не определена.

http://www.lenta.ru/news/2011/06/20/planet/

[instml]

Комета Хартли-2 родилась после столкновения двух других комет

МОСКВА, 4 окт - РИА Новости. Гантелеобразное тело кометы Хартли-2 могло образоваться в результате "мягкого" столкновения двух небольших комет, о чем говорят данные, полученные зондом "Дип Импакт" в ноябре 2010 года, заявили американские астрономы на планетологической конференции EPSC-DPS во французском Нанте.

"После встречи с кометой в ноябре, мы все глубже "вгрызались" в данные, полученные "Дип Импакт", и лучше понимали то, как частицы льда и пыли отделяются от ядра Хартли-2", - пояснил директор расширенной миссии зонда EPOXI Майк А'Херн (Mike A'Hearn) из университета штата Мэриленд в городе Колледж Парк (США).

А'Херн и его коллеги выяснили, что кусочки водяного льда и пары углекислого газа испаряются и двигаются крайне медленно, несмотря на то, что ядро кометы выбрасывает очень большое количество этих частиц при приближении к Солнцу.

Кроме того, "Дип Импакт" показал, что ядро кометы состоит из разнородных частей - теплой "темной" половины, на которой происходят интенсивные процессы газообразования, и холодной "светлой", где скапливаются кристаллы льда, отражающие солнечный свет.

Астрономы подтвердили, что в разных частях ядра кометы выделяются разные газы: большие объемы углекислого газа - в маленькой половине, и небольшое количество водяных паров - в большой.

"Мы предполагаем, что это означает, что две половинки "гантели" сформировались в разных уголках Солнечной системы. "Мягкое" столкновение этих частей спаяло половинки, и промежуток между ними заполнился пылью и льдом", - объяснил А'Херн.

Комету Хартли-2 (103P/Hartley 2), открытую в 1986 году австралийцем Малколмом Хартли (Malcolm Hartley), в ноябре 2010 года посетил американский зонд "Дип Импакт" (Deep Impact), который пролетел на расстоянии 694 километра от ее ядра, сделав около 10 тысяч снимков и проведя множество измерений.

http://ria.ru/science/20111004/449163099.html

[instml]

В космосе впервые нашли "земную" воду

Астрономы, работающие с телескопом "Гершель", впервые обнаружили на комете "земную" воду. Статья ученых появилась в журнале Nature, а ее краткое изложение приводится на сайте ESA.

Известно, что во время формирования Земля была достаточно сухой - близость к Солнцу не позволяла пару замерзнуть в лед, который мог бы войти в состав молодой планеты. Таким образом океаны, покрывающие как минимум две трети поверхности нашей планеты, были принесены на Землю уже после ее формирования.

Главными кандидатами на роль переносчиков воды ученые всегда считали кометы. До последнего времени, однако, данные наблюдений противоречили этим предположениям - в кометном льду было слишком большое соотношение изотопов водорода дейтерия и протия как минимум в два раза превышало аналогичный показатель для земных океанов. Из-за этого, среди прочего, стали появляться гипотезы о том, что 90 процентов воды на Землю могли занести метеориты, а не кометы.

Объектом нового исследования выступала комета Хартли-2, открытая в 1986 году. Используя Гетеродинный датчик для излучения в дальнем инфракрасном диапазоне (по утверждению ученых, самый чувствительный инструмент для регистрации воды из доступных ученым сейчас), который установлен на космической обсерватории "Гершель", ученые смогли померить соотношение изотопов в льду кометы Хартли.

Оказалось, что это соотношение равно 1,61x10^-4, в то время как для земной воды оно равно 1,59x10^-4. Для сравнения аналогичное соотношения для пяти комет из облака Оорта составляло 2,96x10^-4, а для типичных метеоритов-хондритов оно равно 1,4x10^-4. По словам исследователей, это позволяет существенно расширить класс тел (комета Хартли-2 родом из пояса Койпера), которые ответственны за наличие на Земле океанов.

Телескоп "Гершель", который был основным инструментом исследования, был запущен в космос 14 мая 2009 года с космодрома во французской Гвиане. Диаметр главного зеркала аппарат - 3,5 метра (на метр больше, чем у Хаббла). Аппарат предназначен для работы инфракрасном и субмиллиметровом диапазонах.

http://lenta.ru/news/2011/10/06/water/

[instml]

Deep Impact goes for the deep sky
http://planetary.org/blog/article/00003241/

A little fun with Deep Impact deep-sky data
http://planetary.org/blog/article/00003260/



http://epoxi.umd.edu/3gallery/deepsky_challenge.shtml

[instml]

NASA's Deep Impact Spacecraft Eyes the Future



December 01, 2011

Deep Impact Mission Status

PASADENA, Calif. - NASA's Deep Impact spacecraft completed a 140-second firing of its onboard rocket motors on Thursday, Nov. 24. The rocket burn was performed to keep the venerable comet hunter's options open for yet another exploration of a solar system small body.

"The burn was right on the money. Not bad for a spacecraft whose prime mission successfully concluded in 2005," said Tim Larson, Deep Impact project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We've logged a lot of miles and at least one comet flyby since our '05 encounter with comet Tempel 1. With this burn, we keep the door open for Deep Impact logging even more miles and exploring more small worlds before all is said and done."

Last Thursday, Larson and his Deep Impact team watched from their mission support area at JPL as their spacecraft began the maneuver at 4 p.m. PST (7 p.m. EST). The spacecraft's two-minute, 20-second burn changed its velocity by 19.7 mph (8.8 meters per second). If NASA approves a third mission extension for Deep Impact, a second rocket burn will be executed next fall.

Launched in January 2005, Deep Impact traveled about 268 million miles (431 million kilometers) to the vicinity of comet Tempel 1. On July 3, 2005, the spacecraft deployed an impactor that was essentially "run over" by the nucleus of comet Tempel 1 on July 4. Sixteen days after comet encounter, the Deep Impact team placed the spacecraft on a trajectory to fly past Earth in late December 2007. This extended mission of the Deep Impact spacecraft culminated in the successful flyby of comet Hartley 2 on Nov. 4, 2010.

JPL, a division of the California Institute of Technology in Pasadena, manages the Deep Impact mission for NASA's Science Mission Directorate, Washington. The mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

For more information about Deep Impact, please visit: http://solarsystem.nasa.gov/deepimpact .

http://www.jpl.nasa.gov/news/news.cfm?release=2011-367

[instml]

НАСА рассматривает возможность отправить космический зонд Deep Impact в третью экспедицию

ЛОС-АНДЖЕЛЕС, 2 декабря. /Корр. ИТАР-ТАСС Алексей Качалин/. Национальное управление США по аэронавтике и исследованию космического пространства /НАСА/ рассматривает возможность продления срока эксплуатации космического зонда "Дип импэкт". Он справился с первоначально поставленными перед ним задачами еще в 2005 году и до сих пор находится в строю. Космическое ведомство США рассчитывает запрограммировать зонд для выполнения еще одной миссии - исследования одного из малых объектов Солнечной системы, сообщила в четверг Лаборатория реактивного движения /ЛРД/ НАСА в Пасадине /штат Калифорния/. Она ведет управление "Дип импэкт".

Аппарат доказал свою функциональность. 24 ноября зонд, повинуясь командам с Земли, запустил бортовые ракетные двигатели, которые отработали заданные 140 секунд. "Неплохо для космического аппарата, чья главная программа исследований была выполнена в 2005 году", - подчеркнул Тим Ларсон, руководитель экспедиции "Дип импэкт" в ЛРД. "Мы оставляем открытой дверь для того, чтобы "охотник за кометами" оставил за бортом еще много миль и исследовал больше малых миров", - добавил он.

Запуск двигателей был осуществлен с целью скорректировать скорость зонда на 8,8 метров в секунду /ЛРД не уточняет, в сторону повышения или понижения/. Если НАСА продлит срок эксплуатации "Дип импэкт", то потребуется дополнительная корректировка скорости осенью 2012 года.

Американский зонд, запущенный в январе 2005 года, преодолел 431 млн км по пути к комете Темпель-1. 3 июля того же года аппарат в автоматическом режиме выпустил в комету "снаряд" массой 369 кг для анализа выброшенного при столкновении кометного вещества. При "бомбардировке", происшедшей на скорости 37 тыс км в час, выделилась энергия, эквивалентная подрыву 5 тонн динамита. Через 16 дней "Дип импэкт" был перенаправлен так, чтобы миновать Землю в декабре 2007 года. 4 ноября 2010 года аппарат успешно справился со второй задачей - сблизился с кометой Хартли-2, сфотографировал ее, изучил при помощи двух телескопов и инфракрасного спектрографа, отправив накопленный материал на Землю.

http://www.itar-tass.com/c19/287011.html

[pkl]

Вот это да! Какие молодцы! И до чего же живучая машинка... :roll:  :shock: А куда - пока не известно, да?

[instml]

Deep Impact sets path for asteroid encounter in 2020

Flying on its last bit of fuel, NASA's Deep Impact probe is carefully reshaping its course toward a potentially hazardous near-Earth asteroid in hopes the spacecraft can survey the body in January 2020.

Engineer's don't know if Deep Impact has enough fuel to reach the asteroid, and NASA officials in Washington have not committed to funding the extended mssion.

But that isn't stopping engineers from trying, according to Tim Larson, Deep Impact's project manager at the Jet Propulsion Laboratory in Pasadena, Calif.

"There is a lot of uncertainty whether we'll be able to pull this off," Larson said in an interview with Spaceflight Now.

Engineers estimate there are just 4.4 pounds, or 2 kilograms, of hydrazine fuel left inside Deep Impact's propellant tank. About 190 pounds of fuel were inside Deep Impact when it blasted off in January 2005.

NASA management in Washington gave the Deep Impact team authority to fire the spacecraft's thrusters for 140 seconds on Nov. 24, changing the probe's velocity 19.7 mph and changings its trajectory around the sun.

The burn started aiming Deep Impact toward asteroid 2002 GT, a mystical object that regularly crosses paths with Earth. It could be a target for future human expeditions and it has a risk of one day colliding with Earth.

Discovered in 2002, the asteroid is nearly one-half mile wide. But scientists do not know what it looks like or its composition.

A smaller burn by Deep Impact in October 2012 would finish targeting asteroid 2002 GT, setting up for a high-speed flyby in January 2020, Larson said.

"Unfortunately because of the small amount of fuel we have left, we're pretty limited on our choices of where we can go," Larson said.

Scientists at the Jet Propulsion Laboratory identified asteroid 2002 GT as the best opportunity to continue the Deep Impact mission, which completed its first extended phase early this year.

"We did a search of a catalog of available bodies that could be reachable with the fuel we have available," Larson said. "Out of that, about a half-dozen potential bodies came up that we may be able to get to. This is the one that seemed most feasible to get some decent observations and science."

Deep Impact is about the size of a sport utility vehicle. It fired a high-speed impactor into comet Tempel 1 in July 2005, blowing a hole in the nucleus and spraying icy debris into space. The Deep Impact mothership continued flying, and NASA offered the craft for scientists to propose new missions.

NASA approved a proposal named EPOXI to send Deep Impact by comet Hartley 2 and use the probe's high-resolution telescope for observations of planets circling other stars.

The space agency issued another announcement of a possible second extended mission last year, a month before it flew by comet Hartley 2 in November 2010.

NASA has not issued clearance for Deep Impact to continue on toward a third target, but senior officials authorized the Nov. 24 burn to keep the extended mission as an option.

"Whether not it happens in 2020 comes down to whether funding will be available for continued operations and whether the spacecraft will remain healthy," Larson said. "At that point, it would be about 15 years old. So it's hard to predict the condition of all the equipment on-board at that time. We also have to conserve the fuel on-board between now and then."

A senior review by independent scientists will recommend in early 2012 whether to proceed with Deep Impact's second extended mission, according to Michael A'Hearn, the principal investigator for Deep Impact at the University of Maryland.

The panel will weigh the scientific promise of the flyby, the cost of continued operations, and the odds of Deep Impact surviving until 2020.

Scientific observations of extrasolar planets and other comets and asteroids could be possible on Deep Impact's long-duration cruise to the flyby in 2020, scientists said.

"It is still unclear how NASA will proceed with selecting investigations and determining who should be in charge," A'Hearn said, adding he is willing to continue leading Deep Impact's research or step aside for someone else.

Larson said Deep Impact has most recently cost about $5 million to operate each year.

Almost all of Deep Impact's leftover fuel would be used on the flight to asteroid 2002 GT. Reaction wheels control the probe's orientation in space, but thrusters must occasionally fire to unload built-up momentum from the wheels, consuming some of the remaining propellant.

Larger burns next October and fine-tuning maneuvers closer to the flyby may also be required.

But because fuel gauges do not function in the microgravity environment of space, engineers cannot be certain how much hydrazine is left on-board Deep Impact. Controllers can subtract propellant from the tank as it is consumed, or monitor pressures and the thermal behavior of the fuel reservoir.

"There's quite a bit of uncertainty estimating remaining fuel on a spacecraft, particularly when you get this low," Larson said.

http://www.spaceflightnow.com/news/n1112/17deepimpact/

[instml]

all EPOXI data has now been released in PDS here: http://pdssbn.astro.umd.edu/holdings/di-c-hrii_hriv_mri_its-6-doc-set-v3.0/

[Boo]

До 2020 кое-где уже пилотируемую собирались отправить к астероиду-то...
Как Маск на горЕ свистнет.   :mrgreen:

[instml]

2025, ЕМНИП

[instml]

2012.07.12
A'Hearn

Over the last year, the Deep Impact eXtended Investigation (DIXI) science team has been working primarily on the calibration and interpretation of the Hartley 2 data collected back in November 2010. Many research papers have been written and we anticipate publication of a special issue of the journal Icarus later this year with many of those papers. These papers include studies of: the thermal properties of the nucleus of Hartley 2, the shape and mass-loss of the nucleus of Hartley 2, the excited rotational state of Hartley 2 and how it could be influenced by the mass loss, the physical properties of the large, and the icy grains discovered around Hartley 2's nucleus. The special issue will also contain a few papers from Stardust-NExT that had its flyby of Tempel 1 in Feb 2011 to include the interpretation of the impact location made by Deep Impact (as observed by Stardust-NExT a full orbital period later), and so on. We have also written a broader paper on the volatiles in comets, triggered by our own observations of CO2, and how this implies a different formation scenario for comets. Details of a few of these papers will be provided in a later update.

We have also spent time this year using the DI Flyby spacecraft as an observatory. Among other things, we observed comet 2009 P1 Garradd from a distance of 1.4 AU. 1 AU is ~150,000,000 km, so our observations of Garradd were much farther away than our ~700 km flyby distance of Hartley 2 (we don't have enough fuel to go to any more comets, unless of course one is discovered that will come very close to us). Even at that distance, we determined that Garradd's outgassing varies with a period of 10.4 hours, presumably due to rotation of its nucleus. We also obtained the only measurements of its dry ice content, roughly 10% of its water ice content by number of molecules.

The spacecraft has been in an unusual state during the past year, without an official mission, while waiting for NASA's Senior Review of most of the planetary missions requesting extended operations. That review took place at the end of June and we hope to hear in the next month or two whether we will be allowed to continue operating as an observatory, both observing selected comets as we did with Garradd and also carrying out other observational programs on Mars, Jupiter, and exoplanets producing micro-lensing events by passing in front of a star.

http://epoxi.umd.edu/1mission/status.shtml

[instml]

Сделана коррекция траектории.

Deep Impact Spacecraft Completes Rocket Burn
October 04, 2012

Deep Impact Mission Status

PASADENA, Calif. - NASA's Deep Impact spacecraft completed a firing of its onboard rocket motors earlier today. The maneuver began at 1 p.m. PDT (4 p.m. EDT), lasted 71 seconds, and changed its velocity by 4.5 mph (2 meters per second). The rocket burn was performed to keep the venerable comet hunter's options open for yet another exploration of a solar system small body, this time a possible future visit to a small near-Earth asteroid called 2002 GT.

Deep Impact was launched in January 2005. On July 3, 2005, the spacecraft deployed an impactor that was "run over" by the nucleus of comet Tempel 1 on July 4 while the main spacecraft imaged the event. Sixteen days after that comet encounter, the Deep Impact team placed the spacecraft on a trajectory to complete a bonus mission. The extended mission of the Deep Impact spacecraft culminated in the successful flyby of comet Hartley 2 on Nov. 4, 2010.

To date, Deep Impact has traveled about 4.2 billion miles (6.75 billion kilometers) in space.

JPL, a division of the California Institute of Technology in Pasadena, manages the Deep Impact mission for NASA's Science Mission Directorate, Washington. The mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

For more information about Deep Impact, visit: http://solarsystem.nasa.gov/deepimpact .  

http://www.jpl.nasa.gov/news/news.php?release=2012-313

[instml]

Deep Impact targets possible 2020 asteroid flyby

Yesterday, Deep Impact performed a trajectory correction maneuver, firing its thrusters to line up for a flyby seven years from now.  Deep Impact, you might recall, launched January 12, 2005 and flew past comet Tempel 1 on July 4 of the same year. It went on to a bonus encounter with Hartley 2 on November 25, 2010. At the time of the Hartley 2 flyby, we were told that Deep Impact was too low on fuel to be able to set up a third encounter. Since then, though, navigators have identified a target close to Deep Impact's trajectory: asteroid 163249 (2002 GT). The October 4, 2012 rocket burn steered Deep Impact toward a January 4, 2020 flyby of the asteroid.

Asteroid 163249 is pretty small, probably around 800 (plus or minus 400) meters across. That would make it the second-smallest minor planet to be visited by a spacecraft, between Itokawa and Hartley 2 in size -- but by the time Deep Impact gets to it, OSIRIS-REx will have visited a similar-sized one, 101955 (1999 RQ36), which is, by the way, the subject of the Name That Asteroid contest, still ongoing.

Asteroid 163429's trajectory classifies it as a "potentially hazardous asteroid." Not a lot is known about its physical properties, but information should be better by this time next year. That's because it will have a reasonably close approach to Earth next year, passing within 18 million kilometers on June 26. As a possible target of future exploration, there will undoubtedly be lots of telescopes pointed in its direction.

I asked Jessica Sunshine for some details on this proposed encounter, and here's the basic outline (although details could and probably would change). Deep Impact's possible January 4, 2020 flyby would be a nice one, at a close-approach distance of around 200 kilometers and a relative velocity of 7 kilometers per second. That's both closer and slower than the Hartley 2 flyby (which was at 700 kilometers and 12 kilometers per second). Deep Impact would approach the asteroid from its night side, seeing it at very high phase, which means the best science would happen on the way out, with the asteroid at lower phase of around 40 degrees. The encounter would happen while OSIRIS-REx is operating at asteroid 101955, a fun juxtaposition much like the dual comet encounters that happened with Hartley 2 and Tempel 1 two years ago.

But do take notice of the conditional tense I'm using here. A mission extension that would allow Deep Impact to be kept in operation through January 2020 has been proposed, but not yet approved. And we all know the state of NASA's planetary exploration budget. I know that, historically, Deep Impact has done a stellar job of sticking within budget, devising operational tools that keep ongoing costs relatively low. And it would be really cool to be able to compare and contrast asteroids 163429 and 101955. The Hartley 2 encounter was extremely productive, scientifically; there's every reason to expect asteroid 163249 to be full of surprises. But while yesterday's rocket firing keeps Deep Impact's options open, it does not guarantee that NASA will exercise that option.

Deep Impact is now on course to fly close by asteroid 163429 no matter what. I hope that we can watch the encounter through its camera when it does!

http://www.planetary.org/blogs/emily-lakdawalla/2012/10051022-deep-impact-asteroid-flyby.html

[instml]

New Deep Impact Hartley 2 data set

http://www.planetary.org/blogs/emily-lakdawalla/2013/05022157-new-deep-impact-hartley-2.html

[Сергио]

Имxотеп пишет:
Пара дополнений и иллюстраций из статьи в Science.

1) Общая сводка:

 

2) Вращение.
Вращение ядра кометы Хартли-2 складывается из двух составляющих: собственно вращения с периодом 27.8 часа и прецессии оси вращения с периодом 18.3 часа. Оба движения непостоянны, период вращения уменьшается, а период прецессии увеличивается на 0.1% за период.

3) "Снежинки"
Еще до пролета радарное зондирование с Земли выявило вокруг кометы облако частиц сантиметровых размеров. В момент наибольшего сближения с ядром многие крупные частицы были отсняты камерами MRI и HRI. Размер частиц оценивается в 10-150 см для темного "грязного" льда и 1-15 см для чистого льда (второй вариант представляется более вероятным). Судя по яркости внутренней комы, там также присутствует большое количество более мелких частиц. Характерная скорость движения "снежинок" составляет ~0.5 м/с, время жизни - нескольких часов, "дальность полета" - 15 км, хотя некоторые частицы были зарегистрированы в 30 км от ядра. На рисунке ниже показано мгновенное распределение "снежинок" в момент наибольшего сближения.

 

4) Истечение струй с поверхности ядра и их химический состав:

 

5) Сравнительная морфология кометных ядер

 

напоминает астероид Эрос.

[instml]

http://www.unmannedspaceflight.com/index.php?showtopic=5177&view=findpost&p=201872

Target Asteroid 2002 GT Tracked by European Teams
by Staff Writers
Paris (ESA) Jul 23, 2013



Motion of asteroid 2002GT over 5 hours in a 15x15 arcmin field of view. The asteroid is moving rapidly so the telescope is not following stars but the asteroid itself. Observation of the Apollo-class asteroid (163249) 2002 GT performed with the Omicron telescope of the C2PU project (https://c2pu.oca.eu/), by M. Devogele (1, 2), J-P. Rivet (1), P. Tanga (1), Ph. Bendjoya (1), L. Abe (1) and O. Suarez(1) from the Observatoire de la Cote d'Azur, France (1) and the Universite de Liege, Belgium (2). The C2PU 1 m-diameter telescope is based in the Calern observatory of the Observatoire de la Cote d'Azur. Image courtesy C2PU project https://c2pu.oca.eu/

In a recent close-ish flyby, asteroid 2002 GT was studied in detail for the first time by a network of European astronomers. The observations were coordinated by ESA's asteroid centre in Italy, and should prove crucial for a future spacecraft rendezvous.

Asteroid 2002 GT, a relatively large object a few hundred metres across, made a somewhat close flyby of Earth on 26 June, passing us at almost 50 times the distance of the Moon.

The encounter sparked intensive worldwide observations because the asteroid is the target of NASA's Epoxi mission in January 2020.

Last month's flyby was the last chance before then to study the object's diameter, rotation, composition and other physical characteristics.

Ideal opportunity to coordinate response
"The flyby presented an ideal opportunity to exercise the unique 'coordinating function' of ESA's new Near-Earth Object Coordination Centre," says Ettore Perozzi, project leader for NEO services at Deimos Space.

"By alerting and then collating observations from diverse European teams, the Centre was able to provide a comprehensive set of results back to the scientific and space exploration communities, a cycle that wasn't happening before. This is really a first for Europe."

Deimos Space leads a project team that operates the Centre at the Agency's ESRIN site near Rome.

The gathered information will enable a very good characterisation of the asteroid's surface composition, thermal properties, shape and rotation. All of these features are crucial for any spacecraft visit.

Moreover, analysis of its changing brightness indicates the possible presence of a small moon.

Focal point: ESA's NEO Coordination Centre
Gerhard Drolshagen, co-manager of the NEO segment at ESA's Space Situational Awareness programme office, says the 2002 GT event highlighted the potential coordination role that the Centre can play in addition to its primary function of providing information on all known NEOs, including their orbits, impact risk and close approaches to Earth.

"Traditionally, Europe's asteroid community reliably delivered world-class observations and has been credited with many significant discoveries and findings. What was lacking, however, was a central point to coordinate and synthesise data that could function across national and organisational boundaries.

"Our Centre has proven it can act as a driving force and a focal point for the European and international community involved in asteroid science, impact monitoring and mitigation."

Ettore adds: "We now know 2002 GT is a rocky body, belonging to a peculiar transition class that astronomers refer to as "Sq-type".

"It's also a potentially hazardous object, as its orbit crosses that of Earth, so it's certainly a very interesting object, well worth watching."

2002GT observations
ESA's Near-Earth Object Coordination Centre (NEO-CC) received well-documented observations of 2002GT as follows:

o Photometry and light-curve data from the 1 m-diameter C2PU telescope at the Observatoire de la Cote d'Azur , which allows calculation of the rotation period (3.77 hours). The shape of the light curve is also compatible with the presence of a satellite. Spectra and photometric data from Asiago Observatory (University of Padova and Observatory of Padova) which allows determination of the asteroid type (Sq), in agreement with other observations.

o Infrared observations from the Campo Imperatore Station of the INAF Rome Astronomical Observatory. Even under bad weather conditions, teams there were able to spot the asteroid 20 days before Earth flyby.

o Astrometry from Gaia-FUN-SSO. Six telescopes observed 2002 GT providing more than 1000 astrometric measurements. These were sent to the Minor Planet Centre and processed at the Institut de Mercanique Celste et de Calcul des Ephemerides for computing orbital elements.

http://www.spacedaily.com/reports/Target_Asteroid_2002_GT_Tracked_by_European_Teams_999.html

[instml]

http://www.unmannedspaceflight.com/index.php?showtopic=5177&view=findpost&p=201873

speaking of which, there was an optimistic update on the mission at the SBAG meeting earlier this month: http://www.lpi.usra.edu/sbag/meetings/jul2013/presentations/THU_1015_Farnham_EPOXI.pdf

[instml]

После 8 августа потеряна связь с АМС. Предпринимаются попытки восстановить контакт.

Deep Impact in trouble: last heard from August 8

A terse update on the status of the aging Deep Impact spacecraft was posted on the mission website this morning:
We have not received any of our expected observations of comet ISON due to a spacecraft problem. Communication with the spacecraft was lost some time between August 11 and August 14 (we only talk to the spacecraft about once per week). The last communication was on August 8. After considerable effort, the team on August 30 determined the cause of the problem. The team is now trying to determine how best to try to recover communication.
As long as controllers are communicating with a spacecraft, there is hope. When they are not in communication with a spacecraft, that's pretty scary. Good luck to the Deep Impact team on recovering the spacecraft for a future comet or asteroid encounter. It's a great little mission.

http://www.planetary.org/blogs/emily-lakdawalla/2013/09041109-deep-impact-in-trouble.html