#comet’s

#Rosetta’s descent towards region of active pits
▻http://blogs.esa.int/rosetta/2016/09/09/rosettas-descent-towards-region-of-active-pits

Squeezing out unique scientific observations until the very end, #rosetta’s thrilling mission will culminate with a descent on 30 September towards a region of active pits on the #comet’s ‘head’. The region, known as Ma’at, lies on the smaller of the two lobes of #Comet_67P/Churyumov–Gerasimenko. It is home to several active pits more than 100 m in diameter and 50–60 m in depth – where a number of the comet’s dust jets originate. The walls of the pits also exhibit intriguing metre-sized lumpy structures called ‘goosebumps’, which scientists believe could be the signatures of early ‘cometesimals’ that assembled to create the comet in the early phases of Solar System formation. Rosetta will get its closest look yet at these fascinating structures on 30 September: the spacecraft will target a point (...)

#Comets #Instruments #Landing #Operations #Science ##CometLanding #instruments #science #trajectory

#CometWatch 22 August
▻http://blogs.esa.int/rosetta/2016/09/02/cometwatch-22-august-3

This week’s CometWatch entry was taken with #Rosetta’s #navcam on 22 August 2016, when the spacecraft was 6.8 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The average distance to the surface is about 5.6 km, and with an image scale of 0.5 m/pixel, the image measures about 500 m across. The image shows part of the Ma’at region, close to where it transitions into Anuket and Hathor regions on the #comet’s small lobe. It shows a beautiful contrast between smooth, dust covered surfaces, and rather angular outcropping terrain and scattered debris. For more close-up images taken in the last week, be sure to check the OSIRIS image of the day website. The original 1024 x 1024 pixel image is provided (...)

#Comets #rosetta

Krypton and xenon added to #Rosetta’s noble gas inventory
▻http://blogs.esa.int/rosetta/2016/06/14/krypton-and-xenon-added-to-rosettas-noble-gas-inventory

Rosetta has detected the noble gases krypton and xenon while flying close to #Comet_67P/Churyumov-Gerasimenko last month. The detections were made during dedicated orbits between 10 and 31 May, which took the spacecraft to within 10 km of the #comet’s surface, and sometimes as close as 5 km. The discovery was highlighted today by Kathrin Altwegg, Principal Investigator of the ROSINA instrument that made the detections, during a Royal Society meeting on ‘Cometary #Science after #rosetta ’ in London, UK. “We had sporadic hints of krypton while briefly flying at 12 km in early March, but the confirmation was only possible thanks to a longer period of observation during these close orbits,” she says. “Noble gases bound up inside the comet very easily escape into space through sublimation, so (...)

#Comets #Instruments #instruments #science

#CometWatch 24 April
▻http://blogs.esa.int/rosetta/2016/04/29/cometwatch-24-april

This week’s CometWatch was taken by #Rosetta's NAVCAM on 24 April 2016, 28 km from the nucleus of #Comet_67P/Churyumov-Gerasimenko. It captures a beautiful ‘skyline’ taking in parts of the #comet’s southern hemisphere regions. Bes and Geb on the comet’s large lobe lie to the far left of the scene. Zooming in to the exposed cliff faces reveals criss-cross fracture patterns that have also been identified in many other locations on the comet (see an earlier blog post ‘Do comet fractures drive surface evolution?’ for more). The boulder-strewn neck region in the middle of the view features Sobek, which transitions up through Neith and Wosret on the small comet lobe to the right. Also released this week by #rosetta’s OSIRIS team was a stunning narrow-angle camera shot capturing an oblique view over (...)

#Instruments #Operations

#CometWatch 12 November – one year on
▻http://blogs.esa.int/rosetta/2015/11/13/cometwatch-12-november-one-year-on

Today’s CometWatch entry was taken yesterday by #Rosetta’s #navcam, on the anniversary of Philae’s historic landing on #Comet_67P/Churyumov-Gerasimenko last year. The image was taken from a distance of 177.7 km; the image scale is 15.1 m/pixel and the image measures 15.5 km across. It has been lightly enhanced to better show the #comet’s activity. With #rosetta closer to the comet, more surface details can be seen again. On the large lobe, to the left, the relatively flat surface of Aker can be seen to the top, with Khepry to the left and Babi in the foreground. Hints of Anhur can also just be seen beyond Aker. On the small lobe, the circular depression Hatmehit takes centre stage. Philae’s first touchdown point, Agilkia, is to the lower right of Hatmehit in this orientation, with its final (...)

#Comets #Images

#CometWatch 9 October
▻http://blogs.esa.int/rosetta/2015/10/16/cometwatch-9-october

This image of #Comet_67P/Churyumov-Gerasimenko was taken by #Rosetta’s #navcam on 9 October from a distance of 579 km. The image scale is 49.4 m/pixel and the image measures 50.5 km across. The contrast is increased to better see the #comet’s activity, with several distinct active regions clearly visible. In this orientation the comet’s small lobe is in the background, with primarily the Anuket region visible, and the large lobe is in the foreground with parts of Atum, Anubis and Khonsu visible. #rosetta is currently on its return leg of a 1500 km far excursion to study the wider coma and plasma environment from afar, and is scheduled to reach a distance of 450 km from the comet by tomorrow (Saturday). The original 1024 x 1024 pixel image is provided (...)

#Rosetta’s first peek at the #comet’s south pole
▻http://blogs.esa.int/rosetta/2015/10/01/rosettas-first-peek-at-the-comets-south-pole

Using the Microwave Instrument for the #rosetta Orbiter (MIRO), scientists have studied the comet’s southern polar regions at the end of their long winter season. The data suggest that these dark, cold regions host ice within the first few tens of centimetres below the surface in much larger amounts than elsewhere on the comet. Since its arrival at #Comet_67P/Churyumov-Gerasimenko, Rosetta has been surveying the surface and the environment of this curiously-shaped body. But for a long time, a portion of the nucleus – the dark, cold regions around the comet’s south pole – remained inaccessible to almost all #Instruments on the spacecraft. Due to a combination of its double-lobed shape and the inclination of its rotation axis, Rosetta’s comet has a very peculiar seasonal pattern over its 6.5 (...)

#Images #Science #miro #southern_hemisphere #water

#Rosetta reveals #comet’s water-ice cycle
▻http://blogs.esa.int/rosetta/2015/09/23/rosetta-reveals-comets-water-ice-cycle

ESA’s #rosetta spacecraft has provided evidence for a daily water-ice cycle on and near the surface of #Comets. This story is mirrored from the main ESA web portal. Comets are celestial bodies comprising a mixture of dust and ices, which they periodically shed as they swing towards their closest point to the Sun along their highly eccentric orbits. As sunlight heats the frozen nucleus of a comet, the ice in it – mainly water but also other ‘volatiles’ such as carbon monoxide and carbon dioxide – turns directly into a gas. This gas flows away from the comet, carrying dust particles along. Together, gas and dust build up the bright halo and tails that are characteristic of comets. Rosetta arrived at #Comet_67P/Churyumov–Gerasimenko in August 2014 and has been studying it up close for over a (...)

#Instruments #Science #instruments #science

Inside #Imhotep
▻http://blogs.esa.int/rosetta/2015/07/20/inside-imhotep-2

Imhotep, on #Comet_67P/Churyumov-Gerasimenko's large lobe, is one of the most geologically diverse regions observed by #Rosetta. This blog post presents the results of a new paper by Anne-Thérèse Auger from the Laboratoire d’Astrophysique de Marseille (LAM, France) et al, which describes Imhotep’s key features and discusses possible scenarios for this region’s evolution. The post was prepared with inputs from Anne-Thérèse and co-author Olivier Groussin, also from LAM. Imhotep is located close to the #comet’s equator and is relatively flat compared to the overall shape of the nucleus. It caught the attention of scientists on the approach to the comet with its broad smooth area, covering about 0.8 square km, standing out in the first close #Images of this region. Within this intriguing area, a (...)

#Instruments #Science #rosetta #science

Exposed water ice detected on #comet’s surface
▻http://blogs.esa.int/rosetta/2015/06/24/exposed-water-ice-detected-on-comets-surface

This article is mirrored from the main ESA web portal and covers the results published in a new paper in the journal Astronomy & Astrophysics titled “OSIRIS observations of metre-size exposures of H2O ice at the surface of 67P/Churyumov-Gerasimenko and interpretation using laboratory experiments,” by Antoine Pommerol et al. Using the high-resolution #Science camera on board ESA’s #Rosetta spacecraft, scientists have identified more than a hundred patches of water ice a few metres in size on the surface of #Comet_67P/Churyumov-Gerasimenko. #rosetta arrived at the comet in August 2014 at a distance of about 100 km and eventually orbited the comet at 10 km or less, allowing high-resolution images of the surface to be acquired. A new study just published in the journal Astronomy & (...)

#Comets #Instruments #instruments #science

#CometWatch 15 June
▻http://blogs.esa.int/rosetta/2015/06/24/cometwatch-15-june

Today’s CometWatch entry is a single frame #navcam image taken on 15 June, when #Rosetta was 207 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The resolution is 17.7 m/pixel and the image measures 18.1 km across. The image is processed to bring out the details of the #comet’s activity and to highlight the shadows and silhouettes of its two lobes, which in this orientation shows the small lobe to the left and the large lobe to the right. The original 1024 x 1024 pixel image is provided below:

#Images #rosetta

#miro maps #water in #comet’s coma
▻http://blogs.esa.int/rosetta/2015/06/19/miro-maps-water-in-comets-coma

In a paper accepted for publication in the journal Astronomy & Astrophysics, the MIRO team present their first map of water vapour in the coma of #Comet_67P/Churyumov-Gerasimenko. MIRO, the Microwave Instrument for the #Rosetta Orbiter, first detected the emission from water molecules in the coma of Comet 67P/C-G on 6 June 2014, when #rosetta was 350,000 km from the comet, approximately equivalent to the distance of the Earth from the Moon. At the time, the comet was 3.9 AU – about 580 million km – from the Sun. Since early July 2014, the MIRO team have been continuously monitoring water in the comet’s environment, measuring its properties at different locations across the coma. Being in very close proximity to 67P/C-G, Rosetta, with the MIRO instrument on board, can ’dissect’ the (...)

#Science #science

#CometWatch 5 June
▻http://blogs.esa.int/rosetta/2015/06/12/cometwatch-5-june

Today’s CometWatch entry was taken on 5 June 2015, from a distance of 208 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The image scale is 17.7 m/pixel and the image measures 18.1 km across. The image has been processed to bring out the details of the #comet’s activity, which in this orientation shows off the spectacular display around the smaller of the two lobes. The processed image also highlights the shadows cast by the two lobes across the background activity, in particular the sharp shadow and silhouetted large lobe towards the bottom of the scene. The original 1024 x 1024 pixel image is provided (...)

#Images #Rosetta #navcam #rosetta

#CometWatch 1 June
▻http://blogs.esa.int/rosetta/2015/06/09/cometwatch-1-june

Today’s CometWatch entry was taken on 1 June 2015, from a distance of 209 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The image scale is 17.8 m/pixel and the image measures 18.2 km across. The image has been processed to bring out the details of the #comet’s activity, which can be seen all around the sunlit side of the comet. In this orientation the comet’s small lobe is to the left and the large lobe to the right, with much of the southern hemisphere facing towards the spacecraft. The outline of the rim of the large depression Hatmehit can be seen at the very far left, while at the far right a hint of Imhotep can just be made out. The flat surface at the top of the large lobe in this orientation is in the Aker/Khepry region. The rugged terrain that faces us has only become (...)

#Comets #Images #Rosetta #navcam #rosetta

OSIRIS spots boulders in balancing act
▻http://blogs.esa.int/rosetta/2015/05/18/osiris-spots-boulders-in-balancing-act

Scientists from #Rosetta’s OSIRIS team have discovered an unusual formation of boulders in the Aker region on the large lobe of #Comet_67P/Churyumov-Gerasimenko. At first glance they are reminiscent of so-called “balancing rocks” on Earth. Of the three boulders, the largest (labelled with a ‘3’) has a diameter of approximately 30 metres. In an image taken on 16 September 2014 (below), it stands out as having only a very small contact area with the #comet’s surface. It also seems to be perched on the rim of a small depression. “We had noticed this formation already in earlier #Images, however, at first the boulders did not seem to differ substantially from others we had seen,” says OSIRIS scientist Sebastien Besse from ESA, who first noticed the formation. Similar geological formations are also (...)

#Science #instruments #rosetta

#CometWatch 26 April
▻http://blogs.esa.int/rosetta/2015/05/01/cometwatch-26-april

This image of #Comet_67P/Churyumov-Gerasimenko was taken on 26 April and not only presents an incredible view of the #comet’s activity, but also shows off some interesting new views of the comet’s nucleus. The image was taken by #Rosetta’s #navcam from a distance of 98 km from the comet centre. The scale at this distance is 8.4 m/pixel and the image measures about 8.6 km across. One eye-catching region lies in the foreground of the comet’s large lobe, which appears as a smoother swath of material sandwiched between more rugged surrounds. This is also evident in an image taken last month from a different angle, and as such it is interesting to compare the two. Perhaps even more captivating is the intricate pattern of activity streaming in all directions from both the small and the large lobe. (...)

#Images #rosetta

GIADA investigates #comet’s “fluffy” dust grains
▻http://blogs.esa.int/rosetta/2015/04/09/giada-investigates-comets-fluffy-dust-grains

In a recent paper published in the Astrophysical Journal Letters, the GIADA team present their findings on the properties of dust particles from Comet 67P/Churyumov-Gerasimenko. This blog post has been prepared with inputs from lead author Marco Fulle, and GIADA principal investigator Alessandra Rotundi. GIADA, the Grain Impact Analyser and Dust Accumulator, is designed to capture dust particles in the coma of Comet 67P/Churyumov–Gerasimenko as #Rosetta flies around it. The characteristic properties of the dust grains can be used to infer the history of the material being ejected from comet. The latest study focuses on the dust particles collected between 1 August 2014 and 14 January 2015. The GIADA team find that the dust particles impacting on their detectors can be separated into two (...)

#Science #rosetta #science

#CometWatch 22 March
▻http://blogs.esa.int/rosetta/2015/03/30/cometwatch-22-march

This single frame #Rosetta Navigation Camera image was taken on 22 March 2015 at a distance of 77.8 km from the centre of #Comet_67P/C-G. The image scale is 6.6 m/pixel and the 1024 x 1024 pixel image measures 6.8 km across. The image above has been processed to bring out the details of the #comet’s activity, while also emphasising details on the nucleus. The image presents another interesting view of regions previously cast in shadow, particularly on the small lobe around Hatmehit, and of the topography on the large lobe close to Aker and Khepry. (The 9 March image also offered a new view of these regions, from a slightly different angle). At the bottom right, the large lobe is casting a shadow over the broader ‘atmosphere’ around the comet. The original 1024 x 1024 image is provided (...)

#navcam #rosetta

#CometWatch 18 March
▻http://blogs.esa.int/rosetta/2015/03/23/cometwatch-18-march

This single frame #navcam image was taken on 18 March at a distance of 81.4 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The image scale of the original 1024 x 1024 pixel image is 6.9 m/pixel and the image measures 7.1 km across; a cropped, processed version is shown below. The image is processed to bring out the outflowing material while not overexposing the nucleus too much. Indeed, in this image, a few faint but distinct jets of material can be seen rising above the #comet’s larger lobe, with a diffuse nebulosity visible around the entire nucleus. A labelled image is also provided to point out some of the regions on the comet’s surface. In this orientation we can see portions of the larger lobe emerging from the shadows – in particular parts of Aker and Babi – that in many (...)

#Images #Rosetta #instruments #rosetta

OSIRIS detects hints of ice in #comet’s neck
▻http://blogs.esa.int/rosetta/2015/03/13/osiris-detects-hints-of-ice-in-comets-neck

This post is based on information provided by the OSIRIS team at the Max Planck Institute for Solar System Research (MPS) in Germany. If it could be seen with the naked human eye, the nucleus of #Comet_67P/Churyumov-Gerasimenko would be a dark grey all over. With its array of specialised filters, however, #Rosetta’s scientific imaging system OSIRIS can discern tiny differences in reflectivity at different wavelengths across the comet’s surface. In turn, these differences can reveal clues as to the local composition of the comet. The image shown here focuses on the Hapi region of the comet. Hapi is located in the neck between the comet’s two lobes and has in the past months proven to be particularly active, the source of many of the spectacular jets of dust and gas seen in the wider-view (...)

#Images #Instruments #Science #rosetta #science

#CometWatch 6 March
▻http://blogs.esa.int/rosetta/2015/03/09/cometwatch-6-march

Today’s CometWatch entry is a single frame #navcam image obtained on 6 March from a distance of 82.9 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The image has a resolution of 7.1 m/pixel and measures 7.2 km across. The view shows the underside of the #comet’s large lobe in the foreground, with the small lobe in the background. An annotated version of the image is also provided to help identify some of the comet’s regions. You can also find regional maps of Comet 67P/C-G here and here. The original 1024 x 1024 pixel image is provided below:

#Images #Rosetta #rosetta

#CometWatch 20 February
▻http://blogs.esa.int/rosetta/2015/02/25/cometwatch-20-february

Today’s CometWatch entry is a single frame #navcam image obtained on 20 February from a distance of 118.5 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The image has a resolution of 10.1 m/pixel and measures 10.3 km across. The image nicely complements that published on Monday, this time showing the #comet’s small lobe to the right and the large lobe to the left. Some 80 km closer than Monday’s image, details on the comet nucleus are now a little clearer again. For example, the smooth Imhotep region on the large lobe at the far left can be distinguished from the adjacent terrain of Ash, while on the small lobe the cliffs of Hathor stand out (refer to the regional maps here and here if you are unfamiliar with the comet’s regions). Rather captivating is the shadow of the larger lobe (...)

#Comets #Images #Rosetta #rosetta

Closing in again – #CometWatch 18 February
▻http://blogs.esa.int/rosetta/2015/02/23/closing-in-again-cometwatch-18-february

Today’s CometWatch entry is a 1024 x 1024 pixel single frame #navcam image obtained on 18 February from a distance of 198 km from the centre of #Comet_67P/Churyumov-Gerasimenko. The image has a resolution of 16.9 m/pixel and measures 17.3 km across. While the original image (provided at the end of this post) is dominated by the nucleus, increasing the exposure emphasises the nebulosity of the coma and reveals the impressive nature of the #comet’s jets streaming out into space (see image above). This also highlights the “noisy” background – typically a combination of detector noise, background stars, and grains of material ejected from the comet, which are sometimes captured as streaks. Meanwhile on the comet’s large lobe, the dark shadowed region of Aten and the seemingly flat face of Khepry to (...)

#Images #Rosetta #rosetta

Anuket vs. Anubis – #CometWatch 31 January
▻http://blogs.esa.int/rosetta/2015/02/06/anuket-vs-anubis-cometwatch-31-january

This four-image mosaic comprises #Images taken from a distance of 28.0 km from the centre of #Comet_67P/Churyumov-Gerasimenko on 31 January. The image resolution is 2.4 m/pixel and the individual 1024 x 1024 frames measure 2.4 km across. The mosaic has been slightly cropped, and it measures 4.6 x 4.3 km. The scene provides a stunning view of both the #comet’s larger lobe (bottom) and smaller lobe (top right). There is an interesting contrast between the rough appearance of Anuket, the region that starts on the smaller lobe and descends along the side of the comet’s neck, and the smoother material of the Anubis region, visible on the larger lobe in this view, beneath the crags of Seth as seen on the upper edge of the lobe. A prominent jet and other outflows are also portrayed in the image. (...)

#Rosetta #navcam #rosetta

Where is #Philae? When will it wake up?
▻http://blogs.esa.int/rosetta/2015/01/30/where-is-philae-when-will-it-wake-up

These are the two most popular questions currently being asked of the mission – especially on our social media channels – and ones that we will try to answer in this post, including inputs from the OSIRIS team, and from the Lander Control Centre at the German Aerospace Center (DLR). Where is #philae? Ever since Philae touched down on #Comet_67P/Churyumov-Gerasimenko for the final time on 12 November – it is thought to have come into contact with the #comet’s surface a total of four times including the final #Landing – the search has been on to identify it in images. While the CONSERT instrument has helped to narrow down a 350 x 30 m ‘landing strip’ on Comet 67P/C-G’s smaller lobe, a dedicated search in OSIRIS images has so far not been able to confirm the little lander’s final location. Philae’s (...)

#Instruments #Rosetta ##CometLanding #rosetta #trajectory #wake-up