Lost and (almost) found: Rosetta spots Philae on comet 67P's surface in 'stunning' sequence of images - and it could help reveal probe's final resting place
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Ever since Philae made its first of three historic touchdowns on the surface of comet 67P last Wednesday, scientists have been scouring images from the orbiting Rosetta spacecraft to try and find its final resting point on the surface.
And after releasing an initial image showing its first touchdown, scientists have now revealed a 'stunning' sequence of images that show Philae's path to the surface before it bounced to a height of 0.62 miles (1km).
The probe was only meant to land once on the surface but, after a thruster failed to work and harpoons failed to fire, it bounced twice before becoming wedged in darkness by a cliff.
While these images only show the moments before and after the first bounce, Rosetta scientist Dr Mark Bentley told MailOnline the final frame was crucial in working out which direction the probe went on the comet - and where exactly it is now.
'It's just stunning to see it there,' he said. 'And this last image is the critical one. It shows us the direction it is bouncing off in.'
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This incredible series of images shows Philae bouncing on the surface of comet 67P. The times are in GMT. The final image in the top right shows the direction the probe went in after its first bounce - and scientists are hoping to find where it ended up soon
The remarkable mosaic of images revealed by Esa in a blog post was taken by Rosetta's Osiris camera over a 30 minute period spanning the first touchdown.
In the mosaic the time of each image is shown in GMT, and a comparison image showing the first touchdown before and after the lander hit the ground is also shown.
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The images were taken with Rosetta's narrow-angle camera when it was 9.6 miles (15.5km) from the surface of the comet.
The whole image has a resolution of 11 inches (28cm) per pixel, while the enlarged insets each show a section 56 by 56 feet (17 x 17 metres) in size.
On the left can be seen Philae making its descent towards the comet. The image taken after the touchdown, at 15:43 GMT, confirms that the lander was moving east on the comet at a speed of about 0.5 metres per second.
The final location of Philae remains a mystery, but it is known that it made another bounce at 17:25 before coming to its final resting place at 17:33.
And Esa says that they are confident of finding where the lander is now using a combination of images from the Rosetta spacecraft.
'What we're seeing so far is the first bounce, the original landing site,' Dr Bentley told MailOnline. 'The final frame shows the lander heading off on the first bounce, its largest bounce.'
Dr Bentley also explained that the images reveal the huge change of direction experienced by the lander as it hit the surface.
This, he said, may have been due to the dampening of the legs as they hit the surface, or Philae may have hit a slope that changed its angle.
He is also confident that the final resting point of Philae will be found, although he adds it will be difficult owing to the position of the Rosetta spacecraft.
After Rosetta dropped off Philae towards the surface, the orbiting spaceraft had to do a manoeuvre to keep its visibility open.
This saw it raise its orbit to a height of about 25 30 miles (40 or 50km), which will mean the later images of the third and final landing site will likely be of a worse resolution.
Rosetta's lander captivated the world by landing on the surface of a comet last Wednesday but went into hibernation mode late on Friday when its primary battery ran out of power.
However, in about 60 hours of operations on the surface, scientists said they managed to complete 90 per cent of the primary science - and anything else the lander can do will be a bonus.
We've found Philae! This animation shows Philae touched down for the first time almost precisely where intended, Esa said. It subsequently rebounded and, after touching down a second time, came to rest where it is now - a still unconfirmed location likely outside of these images
This close-up image shows the moment the Philae lander bounced off the surface for the first time, on its way to a height of 0.62 miles (1km), before returning to the surface of the comet and bouncing again. It can just be made out as a few lighter pixels than the comet
'Welcome to a comet!' Esa tweeted this remarkable picture from comet 67P confirming Philae's successful landing on the surface on Wednesday - but scientists now face an anxious wait to see how much scientific data they managed to get from the probe before it ran out of power on Friday night after using all ten of its instruments
Wedged in: This image, annotated by Emily Lakdawalla from The Planetary Society, shows the precarious position the lander is in on the surface. At the top, the view into space can be seen. One of the feet is obscured from view. The bottom left image is the direction that the Mupus hammer instrument was in when it took readings from the surface of the comet
Goodbye! This series of images shows the lander as it headed towards the comet's surface after Rosetta released it
Of the numerous instruments used by the lander, one was designed to measure the temperature of the comet while a drill was used to collect samples and analyse them.
After a successful manouevre to rotate the largest solar panel out of the shadow of the cliff the probe is wedged against, scientists say there is a chance the probe might wake up again in a few months when the comet is closer to the sun and there is more sunlight available.
On Friday scientists made contact with Rosetta's lander for the last time and managed to turn it towards the sun after using its drill in a last gasp attempt to charge its batteries.
Controllers hope that by exposing one of the larger solar panels to the meagre sunlight that is falling on one of the smaller ones, they can provide enough power to charge its batteries.
They now face an agonising wait to see if, and when, it wakes up. The probe is thought to be resting at an angle in the shadow of a crater wall more than half a mile from its planned landing site.
Esa is also preparing to release the first scientific results in a few weeks from the Philae mission to comet 67P, with data hoped to include information of the origins of life and water on Earth.
The lander's Twitter feed broke the news of its demise, saying: 'I'm feeling a bit tired, did you get all my data? I might take a nap…' - but then added its journey has only begun, tweeting: 'I did it! I became the first spacecraft to land on a comet & study it! But it's not over yet…'
Hammer time: On Thursday Philae deployed its Multi Purpose Sensor (Mupus) on the comet, pictured here on Earth before it was attached to Philae. This extendable arm is designed to measure the thermal and physical properties on the comet. Mupus has a small hammer, and the up and down motion could give Philae the jolt it needs to fall onto all three feet. The team has now confirmed the instrument worked 'flawlessly'
'We are happy,' said Stefan Ullanec, one of the mission's leaders.
'We even can watch it falling asleep which is a little bit sad but it can give us data that we want to have.'
Ullanec confirmed the lander was able to send all of its data back to Earth before it 'died' - and celebrated with champagne as the rover's battery power slowly ebbed away.
'Philae has fallen into 'idle mode' - a possibly long silence. In this mode, all instruments and most systems on board are shut down,' the European Space Agency said on its blog in a post entitled Our Lander's Asleep.
The lander's Twitter feed broke the news of its demise, saying: 'I'm feeling a bit tired, did you get all my data? I might take a nap…' - but then added 'I did it! I became the first spacecraft to land on a comet & study it! But it's not over yet…'
They also revealed they had spotted the lander's first landing site, which was captured in images from Rosetta - but still were not sure where it had ended up after two more 'bounces'.
'The rotation of the lander's body could result in more power if one of the larger solar panels can catch the illumination that is falling on the smaller,' said Esa's Mark McCaughrean, senior science advisor.
'All things being equal, the same amount of sunlight falling on a larger panel should result in more power being generated.'
Philae was thought to be partially in darkness beneath a cliff and, crucially, its largest solar panel was not receiving any sunlight.
This means its secondary battery could be properly charged unless it was rotated after its primary battery ran out of power.
Esa had been unsure whether to try and rotate the lander into sunlight, so that it can survive for longer on the surface, or to put it into hibernation and wait for the comet to get closer to the sun in a few months - when there will be more sunlight, but it might be too hot for Philae to survive.
All of Philae's instruments were successfully used including a drill to collect samples from the surface and analyse them.
Mission director, Paolo Ferri, told MailOnline that using the drill was their 'last ditch' attempt to get material from the comet before Rosetta's lander, Philae, ran out of battery.
'It's time to take more risks,' he said last Friday. 'We're now coming to the end...The drill could capsize the lander, which would be terrible, because we will lose the signal completely. But it could also provide us with important data.'
Before using the drill, in a Google hangout mission scientists said the lander had performed 80 to 90 per cent of the primary science of the mission, and anything else it could do would be a bonus.
While Philae's location remains unknown, images suggest the probe landed with two legs on the ground and one partially pointing into space, which is severely limiting its access to sunlight.
It is hoped data returned to Earth on what exactly the drill found beneath the comet's surface could help scientists understand how the solar system formed 4.5 billion years ago.
And on Friday the team experienced what Ferri described as '50 minutes of terror' when the dying probe's signal took longer than expected to reach mission control in Darmstadt.
'If I have contact tonight [Friday] with Philae, that will be absolutely fantastic,' said Ferri. 'If we manage to complete the drilling, I think we can say the prime mission has been totally successful.'
Exactly how much data was returned from the probe before it died is not yet known.
Engineers also deployed other scientific instruments despite Philae's precarious position, and received confirmation that its temperature probes were successfully deployed.
The mission control team had also considered a daring 'hop' using Philae's landing gear to get all the probe's limbs back on the ground. However, Ferri told MailOnline that manoeuvre was a 'crazy idea' and ultimately it was not attempted.
He said another idea was rotating the lander so that its largest solar panel is facing the sun, a decision they ultimately went with.
Daring descent: Philae is pictured here as a tiny dot as it free falls to the icy comet's surface. Rosetta's Osiris wide-angle camera took the image of the lander (circled) at 14:19:22 GMT on Wednesday. Separation occurred onboard the spacecraft at 08:35 GMT, with the confirmation signal arriving on Earth at 09:03 GMT. The Rosetta team is now searching for a clear sign of the lander on the surface of the comet
Three historic landings: This graphic shows the team's current best guess at how events unfolded. The probe landed on the comet at around 3.30pm GMT on Wednesday but then bounced twice - first to a height of 0.62 miles (1km) and then to a much lower height of 65ft (20 metres) before coming to rest. It is currently thought to be about 0.62 miles (1km) from its intended landing site
The lander is now in hibernation but may come 'back from the dead' when the comet gets closer to the sun and there is more sunlight.
It's thought that all ten of the instruments on board the spacecraft sent back data, and the solar panels are in good working order, Esa said.
The instruments include APXS, Civa, Consert, Ptolemy, Mupus, Rolis, Romap, SD2 and Sesame - all of which are designed to collect varying data from the comet.
The final instrument to send data back was the drill, SD2, which allowed Philae to take 4.5 billion-year-old samples from the comet - although how successful it was remains to be seen.
The probe landed on the comet at around 3.30pm GMT on Wednesday but then bounced twice - first to a height of 0.62 miles (1km) and then to a much lower height of 65ft (20 metres) before coming to rest.
It is also thought to be about 0.62 miles (1km) from its intended landing site.
Scientists described the ground as being more like a 'trampoline' than rock, owing to its soft and powdery texture, which may have caused the unsteady landing of the probe.
Good morning, Earth! It's been a busy night at #67P! Now that I'm back in touch with my team, I'll tell you all about it! #CometLanding
— Philae Lander (@Philae2014) November 14, 2014
Illustrated here are the various scientific instruments on the Philae lander that will be used to study the comet when attached to the surface
Is Philae stuck in a cave? Pictured is panoramic image of the surface of comet 67P/ChuryumovñGerasimenko captured by Rosetta's lander. Superimposed in the centre of the image is a sketch of the lander in the position the Esa team currently believe it to be resting. It is thought that one of its legs is sticking up into space while the other two are in contact with the comet
Where is Philae? This image shows where the probe originally landed (marked by a red cross on the left) as well as where it may have ended up after bouncing around on the comet's surface (proposed region shaded in red on right). Scientists are yet to discover its precise location
Crash landing: The location of the first touchdown point of the Philae lander on comet 67P/C-G, marked on an image from Rosetta's OSIRIS narrow-angle camera taken from a distance of 18.6 miles (30 km). The probe bounced twice before coming to a rest on the comet
A bouncing probe: This composite image shows the expected initial landing site (red square) of Philae on the surface with a picture, inset, it took before it bounced and landed half a mile away. The initial bounce took it to a height of 0.62 miles (1km) above the comet's surface
Touchdown: The location of the first touchdown point of Philae on comet 67P, marked on an image taken from a distance of 31 miles (50 km)
First surface image: This was one of the early images released by Philae on its way to the surface. For reference, the rock towards the top right is 13 ft (four metres) wide. It's thought this image was taken before the probe bounced on the surface for the first time
'At the moment, I feel like my feet are not touching the ground,' said Ferri. 'Last night we didn't have enough information, and I was still a bit nervous.
'When I came in this morning, everyone was so quiet. But this is a great feeling.'
There are several cameras fitted around Philae's exterior known as the Comet Infrared and Visible Analyser, but it has been reported that one of them has apparently photographed the sky. The cameras are intended to look out on the surface, as opposed to upwards.
The immediate landing on Wednesday was not without its problems either.
At Esa's mission control, a faint radio signal came back from the Philae lander at 4pm GMT - proof that it had finally reached the surface of the comet 67P/Churyumov-Gerasimenko after a decade-long chase through space.
Shrouded in darkness: Esa has revealed new images of the surface of the comet highlighting some of the features on the surface (shown). However, many of the images are badly lit, suggesting Philae is partially shaded and therefore not getting enough sunlight
Cliff face: The image on the left shows one of the first views of the comet that was returned. Increasing the contrast revealed the large rock nearby, shown on the right, which might be a nearby cliff. Esa scientists believe the cliff may be just metres away from the probe
Intending landing: The probe landed on the comet at around 3.30pm GMT yesterday but then bounced twice, first to a height of 0.62 miles (1km) and then to a much lower height before coming to rest. The comet is about 2.5 miles (4.1km) wide and 2.8 miles (4.5km) long
Hello! An update on life on #67P - Yesterday was exhausting! I actually performed 3 landings,15:33, 17:26 & 17:33 UTC. Stay tuned for more
— Philae Lander (@Philae2014) November 13, 2014
But when it first made contact with the surface it failed to fire harpoons that would have kept it attached to the comet.
This resulted in it bouncing to a height of 0.62 miles (1km) above the comet before again landing on the surface. It then bounced again, but to a much lower altitude.
'Drifting into space is still a major worry,' continued Mr Bentley. 'At the moment the comet is still inactive. Philae is sitting on the surface and operations can all go ahead.'
'If it's not anchored there's a problem with what to do when drilling for example and several instruments designed to sample the environment.'
'If you try to push down with the drill it could lift the lander off the surface. So those operations will be suspended until the Esa team knows how stable it is.'
He also confirmed that it was not clear why the harpoons didn't fire and attempts to fire them again to keep Philae attached to the surface could be problematic. Firing them could push the spacecraft off the surface as its thruster on top to hold it down is not working.
Five-image montage of Osiris images taken around the time of landing when Rosetta was 11 miles (18 km) from the centre of the comet
The final approach: This image shows comet 67P/CG from a distance of approximately 1.8 miles (3km) from the surface. Philae is now thought to be on the surface but its exact orientation is unknown. It bounced twice before coming to rest
What's next for Philae? Pictured are the entire array of sensors that will reveal what life on a comet is like. So far, nine out of ten of Philae's instruments have been deployed, and the drill may be used later today before its battery runs out
A postcard from 67P: Pictured is the first panoramic 'postcard' from the surface of a comet. It shows a 360º view around the point of final touchdown. Parts of Philae's landing gear can be seen in some of the frames
Dr Stephan Ulamec, who oversaw the unprecdented landing, said it was not clear if its three ice screws had deployed either. These are a passive device used to keep Philae attached to the surface but without the use of the harpoons they could be important in keeping it anchored.
'Did we just land in a soft-sand box and everything is fine? Or is there something else happening? We still do not fully understand what has happened,' he said.
Despite the unknowns, the team was treating the landing as a success this week. Further data will be forthcoming later today that will confirm the state of Philae on the surface.
On Wednesday, British scientist Dr Matt Taylor, who played a key role in the mission, said: 'To see this mountaineering effort, that we've descended a lander to the surface of a comet, I can't put words to it. It's beautiful.'
And the expert was so confident of success that he had even had an image of the space probe tattooed on his right leg.
Before the attempt on Wednesday, there was also a good luck message from a man who had once boasted of boldly going into space himself.
Star Trek actor William Shatner sent the team a video in which the 83-year-old said: 'Good luck Rosetta, Philae's gonna land.'
One scientist then described the seven hours of 'terror' they went through to drop the Philae lander 13.6 miles (21.9km) above the comet from its mothership, Rosetta.
Dr Matthew Genge, of Imperial College London, said during the wait: 'This is the most difficult landing in space history - like landing a balloon in a city centre on a windy day with your eyes closed.'
Much of the equipment aboard the lander was switched on for the first time after lying dormant during the ten-year journey.
Klim Churyumov, one of the Ukrainians who discovered the comet 45 years ago and named it, said from mission control in Darmstadt, Germany: 'We saw the first light from this comet in 1969, now we are landing on it. It is a fantastic, outstanding event, the first like it in human civilization.'
New address: The lander announced its arrival on Twitter with this historic tweet for its ten year mission. Throughout this week, mission control have been communicating Philae's status through social networks as the world awaits news of its battery life
Ptolemy, a British-built laboratory the size of a shoebox, will be used to analyse the composition of samples from the 4.5 billion-year-old comet.
Scientists hope the £1 billion ($1.6 billion) project will solve some of the greatest puzzles in science - including the origins of life on Earth.
Open University Professor Ian Wright, who helped create Ptolemy, said: 'The idea that comets may have brought the building blocks of life to Earth is one of the reasons why we want to study them.'
Professor Stanley Cowley, planetary scientist at the University of Leicester, added: 'It is an interesting relic from that otherwise inaccessible epoch.'
'It's complicated to land on a comet, and complicated to understand what has happened during this landing,' said Dr Stefan Ulamec, Philae Lander Manager.
'The good news is we touched down, we had a clear signal and recieved data.
'The not so good news is that the anchoring harpoons did not fire. We looked into the data, and we don't fully understand what has happened.
We had fluctuations in the radio link, but it always came back again.
'Some of the details indicate the lander may have lifted off again, it is bouncing.
'Two hours later, this stopped. We may have landed not once, but twice.'
In an emotional speech, Esa director general Jean-Jacques Dordain said: 'It's a big step for human civilisation.'
The confirmation of the landing was relayed via Rosetta to Earth and picked up simultaneously by a ground station in Malargüe, Argentina and Madrid, Spain, before being confirmed in Darmstadt.
Ahead of the landing, Rosetta took a number of images of Philae during its daring descent. This view shows the lander's consert antennae deployed. It also shows three lander feet and the Rolis descent camera boom
WHAT COULD HAVE HAPPENED IF THE THRUSTER DIDN'T WORK?
This morning it was revealed that the cold thruster - a nitrogen thruster - on top of the Philae lander was not working properly. This meant the Philae lander relied solely on its screws and harpoons (illustration shown) to ensure it did not bounce off the surface of the comet
When Philae touched the surface of the comet it fired harpoons into the surface to keep it anchored there.
To keep it attached to the surface a thruster at the top was meant to push it down as the harpoons fired.
But this morning, the thruster didn't appear to be working - and it was confirmed the harpoons didn't fire.
This meant the lander may have had to rely solely on screws on its legs.
The surface was much softer than they expected, so there were some concerns that Philae was not securely fixed on the comet – although from a software point of view things seemed to be fine.
Engineers may attempt to fire the anchors again soon in order to keep Philae attached to the surface of the comet.
'It's complicated to land on a comet, and complicated to understand what has happened during this landing,' said Dr Stefan Ulamec, Philae Lander Manager.
'The good news is we touched down, we had a clear signal and recieved data.
'The not so good news is that the anchoring harpoons did not fire. We looked into the data, and we don't fully understand what has happened.
We had fluctuations in the radio link, but it always came back again.
'Some of the details indicate the lander may have lifted off again, it is bouncing.
'Two hours later, this stopped. We may have landed not once, but twice.'
'Esa and its Rosetta mission partners achieved something extraordinary today,' said Dordain.
'Our ambitious Rosetta mission has secured another place in the history books: not only is it the first to rendezvous with and orbit a comet, but it is now also the first to deliver a probe to a comet's surface.'
'After more than 10 years travelling through space, we're now making the best ever scientific analysis of one of the oldest remnants of our solar system,' added Alvaro Giménez, Esa's director of Science and Robotic Exploration.
'Decades of preparation have paved the way for today's success, ensuring that Rosetta continues to be a game-changer in cometary science and space exploration.'
'Hollywood is good, but Rosetta is better,' - said the UK Space Agency CEO Dr David Parker.
Esa director general Jean-Jacques Dordain (pictured) said: 'This is a big step for human civilisation...Esa and its Rosetta mission partners achieved something extraordinary'
Bye Rosetta! This image released shows the Philae lander's view of the Rosetta spacecraft 50 seconds after it was released at 08.35am GMT. It is blurry because the probe was rotating at the time
Rosetta has chased comet 67P/Churyumov–Gerasimenko through space for more than ten years in what has been described as 'the sexiest, most fantastic mission ever'
Rosetta has chased comet 67P/Churyumov–Gerasimenko through space for more than ten years in what has been described as 'the sexiest, most fantastic mission ever'.
Speaking live on TV, Matt Taylor, project scientist of Rosetta, talked about the complexities of the mission.
'I said she was sexy but I never said she was easy,' he said, describing the thruster issue that worried scientists earlier today.
Despite this, after a four billion mile (6.5 billion km) journey, the probe successfully released Philae from its grip to land on the comet, travelling at 1 metre (40 inches) per second relative to the comet.
At 08.35 GMT yesterday, mission control in Darmstadt, Germany, sent a command to release the Philae probe from Rosetta's grip. This picture shows the neck region of Comet 67P/Churyumov-Gerasimenko. It was captured around 4.8 miles (7.7km) from the surface of the comet
A view further away taken by Rosetta's Osiris camera. 'It's me… landing on a comet and feeling good!', Philae tweeted
LA vs 67P: This image combines a photograph of Los Angeles with an image from the Rosetta spacecraft rendezvousing with Churyumov-Gerasimenko, prior to going into orbit and eventually landing. The comet is around 2.2 by 2.5 miles (3.5 by 4km)
Immediately after the image was released, Philae tweeted: 'It's me…landing on a comet and feeling good!'.
The separation of Philae from Rosetta was confirmed at 9.03am GMT yesterday, and just after 11am GMT mission control in Darmstadt, Germany received a signal confirming the lander was working.
Throughout the day, the lander transmitted data and images back to Earth.
'Everything looks really, really good,' said Philae lander manager Stephan Ulamec.
However, the success of the mission hung in the balance because Philae had a faulty thruster, which meant had to rely solely on its ice screws in its legs and harpoons to attach itself to the surface - but the latter failed to deploy.
Yup. We're soft landing on a comet today. Normally my "We" means @NASA. But in this case it's @ESA, the European Space Agency
— Neil deGrasse Tyson (@neiltyson) November 12, 2014Now in contact with @Philae2014 as it descends to surface of #67P - lander science data download expected to start 13:05CET #CometLanding
— ESA Operations (@esaoperations) November 12, 2014'This is the most difficult landing in space history, like landing a balloon in a city centre on a windy day with your eyes closed,' said Matthew Genge, a senior lecturer in Earth and planetary science at Imperial College London.
At 08.35am GMT yesterday the mission control team in Darmstadt, Germany, sent a command to release the Philae probe from Rosetta's grip.
The probe was in free fall for 'seven hours of terror', before attempting to land on the icy surface of comet 67P/Churyumov-Gerasimenko at a site called Agilkia.
'We'll need some luck not to land on a boulder or a steep slope,' said Stephan Ulamec before the landing.
And speaking to Astronomy Now, head of mission operations Paolo Ferri said they had received both positive and negative readings from the thruster.
'We don't know whether the motor is working or not. We have inconsistent readings,' he said at the time. Ultimately, it failed to work.
Nice to talk to you again, @ESA_Rosetta! #CometLanding
— Philae Lander (@Philae2014) November 12, 2014SEPARATION CONFIRMED! Safe journey @Philae2014! http://ift.tt/1tFPhps
— ESA Rosetta Mission (@ESA_Rosetta) November 12, 2014
This picture from mission control shows the team preparing to receive confirmation from the Philae lander that it had separated from Rosetta yesterday morning, which was confirmed just after 9am GMT
This graphic details how the Philae lander was supposed to touched down the surface of comet 67P. Without its cold thruster on top, however, the landing was due to be even more risky than thought - and ultimately the craft bounced twice on the surface before coming to rest
The team in Darmstadt, Germany, are pictured here celebrating as news of Philae's separation from Rosetta was received yesterday
Esa also revealed this new image showing how the comet would dwarf London
This is an artist's impression of Philae, showing how it made its way to the surface of the comet yesterday
Craggy: Pictured is a mosaic of 67P/Churyumov-Gerasimenko taken by Rosetta several week before it released its Philae probe to land on the comet's surface. Mission scientists spent months deliberating over where to land the probe due to the comet's uneven surface
Anxious: Scientists (mission controller Paolo Ferri pictured in foreground) faced a gruelling seven-hour wait to discover if the Philae probe had managed to safely land on the comet it has chased for 10 years
Esa successfully made contact with the Philae lander after it separated from the Rosetta spacecraft yesterday morning at 08.35am GMT. Pictured right is Paolo Ferri, Head of Mission Operations, celebrating making contact with Philae before the landing attempt
Rosetta has also been aiming to work out the plasma characteristics of the comet (illustrated)
WHAT IS THE MIDAS INSTRUMENT?
The Midas instrument on Philae is designed to study the dust particles flung from the comet
Midas is the Micro-Imaging Dust Analysis System. It is designed to study the dust particles flung from the comet as it is heated by the sun and becomes active.
When comets pass through the inner solar system, the ices buried below their dark surface are gradually heated. As this gas streams away from the comet's surface, it drags along dust particles – themselves tiny pieces of rock, ice and organic material.
Sunlight reflected from billions of such particles result in the beautiful dust tails seen from Earth on particle population, size, volume and shape.
Midas is one of several instruments that will study cometary dust. To collect particles Midas has a funnel, which usually points towards the comet.
Behind this is a wheel with sticky targets mounted around its circumference. After dust has been collected, the wheel is rotated to move the dust to the microscope for analysis.
By scanning over the dust grain, line by line, scientists can build a 3D picture. Knowing the size, shape and structure of these particles tells us about how and where these particles formed.
These particles are remnants of when the solar system formed 4.5 billion years ago and could reveal how planets formed, and perhaps on life came to be on Earth.
Engineers at Rosetta mission control have made history by landing the Philae probe on comet 67P. Pictured is an artist's impression
The day's events were preceded by a brief moment of worry when Philae 'took a bit longer than expected' to be activated, said Paolo Ferri, mission leader at Darmstadt.
'We were a bit worried at first that the temperature would be wrong (for the descent) but it all worked out. We didn't lose any time,' Ferri said.
No one has ever attempted such a daring feat, and even Esa engineers admit they initially thought it sounded more like science fiction.
Scientists hope that Rosetta and Philae could help unravel secrets of how the solar system formed 4.5 billion years ago.
Emotions at mission control were running high ahead of the landing. 'This, for me, is a wonderful dream come true,' Paolo Ferri, mission director told MailOnline. 'Just thinking about it…I have tears in my eyes.
'You spend a lot of your time in very odd situations with [Rosetta], working weekends, and getting calls in the middle of the night. It's not fair to compare it to a relationship with a human, but it's very close.'
When it was launched in 2004, Rosetta was so far from 67P that it had to pass Earth three times and Mars once, so that it could use the planets' gravity to slingshot its way deep into the solar system.
The spacecraft will spend more than a year studying the comet, which is made up of material left over from when our solar system was first created 4.5 billion years ago.
Ahead of the landing, Esa has published a series 'beauty shots', taken by Rosetta's navigation camera, revealing the varied and dramatic terrain of the mysterious rock.
Rosetta has chased comet 67P/Churyumov–Gerasimenko through space for more than ten years in what has been described as 'the sexiest, most fantastic mission ever' (illustration of solar system shown)
The images shows a raised plateau on the larger lobe of Comet 67P/Churyumov-Gerasimenko. It was captured from a distance of 6 miles (9.8 km) from the center of the comet
Incredibly, many of the images were taken at less than six miles (10km) from the comet's surface, and highlight what a challenging task Philae engineers have ahead of them.
The Philae probe aims to analyse the comet in more detail than Rosetta ever could. The results, Esa claims, could completely rewrite the history of how the Earth formed.
As Philae descended, it travelled at a walking speed of 3ft (one metre) per second relative to 67P while the duck-shaped rock is rotating constantly.
Philae will need to be released with pinpoint accuracy as its landing site contains a mix of sheer cliffs and deep craters - any of which could scupper its chances.
Scientists are aiming to land on a spot named 'Agilkia' on the smaller 'head' lobe of 67P after Philae is released from a distance of 14 miles (22.5km) from the centre of 67P.
This image shows the Agilkia landing site on Comet 67P/ChuryumovGerasimenko, taken with Rosetta's navigation camera on 6 November. It was captured at a distance of 22 miles (35.5km)
And even if Philae lands safely, it will need to attach itself to the comet using harpoons.
Philae is able to withstand temperatures of 150°C (300°F), but it could become too hot to operate as the comet travels towards the sun.
But if it all goes to plan, it could trigger more mission to comets in the future.
'The other scientific instruments are collecting a huge amount of data and I'm sure they'll provide to the scientific community a humongous richness,' Jose Pellon-Bailon, one of eight flight engineers responsible for Rosetta, told MailOnline
At the moment, communication between Rosetta and mission control take 28 minutes and 20 seconds each way - the time it takes for a signal to travel 315 million miles (510 million km) to Earth.
'It's difficult, in the sense that you are commanding something and you are seeing the effects almost one hour later,' says Pellon-Bailon. 'If we land on the comet, it will be very emotional.'
But Pellon-Bailon said his team were fully prepared, even down to what they ate on the day.
Peanuts are crucial. 'We found out that people at Nasa eat peanuts on the day of the special activity. In a mission that is problematic, they will always have peanuts on the table.'
The bizarre rituals at mission control are hoped to steady nerves as engineers perform complex manoeuvres around the comet.
Pellon-Bailon says when he first got involved in the mission in the early 1990s, it sounded to him like science fiction. Even now, he can't quite believe they've reached the comet.
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