Missing comet lander Philae spotted at last: ESA (Update 2)

Missing comet lander Philae spotted at last: ESA (Update)
Rosetta's lander Philae has been identified in OSIRIS narrow-angle camera images taken on 2 September 2016 from a distance of 2.7 km. The image scale is about 5 cm/pixel. Philae's 1 m-wide body and two of its three legs can be seen extended from the body. The images also provide proof of Philae's orientation. A Rosetta Navigation Camera image taken on 16 April 2015 is shown at top right for context, with the approximate location of Philae on the small lobe of Comet Churyumov-Gerasimenko marked. Credit: Main image and lander inset: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; context: ESA/Rosetta/ NavCam – CC BY-SA IGO 3.0
Europe's Rosetta spacecraft has finally spotted its tiny lander Philae, thought to be lost forever, stuck in a ditch on the surface of a comet hurtling through space, ground controllers said Monday.

"THE SEARCH IS OVER! I've found @Philae2014!!" the European Space Agency (ESA) tweeted on behalf of Rosetta, orbiting comet 67P/Churyumov-Gerasimenko at some 682 million kilometres (424 million miles) from Earth.

The agency released a photo of the washing machine-sized robot lab on the comet's rough surface, one of its three legs thrust dramatically into the air.

This was the first sighting of Philae since its rough landing in November 2014.

The image was captured by Rosetta's OSIRIS narrow-angle camera on Friday and downloaded two days later—just weeks before the official end of the ground-breaking science mission to unravel the mysteries of life on Earth.

"With only a month left of the Rosetta mission, we are so happy to have finally imaged Philae and to see it in such amazing detail," Cecilia Tubiana of the OSIRIS camera team, the first person to see the images, said in a statement.

The Twitter page of Philae, its communications unit switched off in July, remained silent.

The 100-kilogramme (220-pound) probe touched down on comet 67P in November 2014, after a 10-year, 6.5 billion kilometre (four billion-mile) journey piggybacking on Rosetta.

Missing comet lander Philae spotted at last: ESA (Update)
Close-up of the Philae lander, imaged by Rosetta's OSIRIS narrow-angle camera on 2 September 2016 from a distance of 2.7 km. The image scale is about 5 cm/pixel. Philae's 1 m-wide body and two of its three legs can be seen extended from the body. The images also provide proof of Philae's orientation. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Philae bounced several times after its harpoons failed to fire, and ended up in a ditch shadowed from the Sun's battery-replenishing rays.

Until now, nobody knew exactly where.

The final hour

The tiny lab managed to conduct 60 hours of experiments and send home data before running out of power and entering standby mode on November 15, 2014.

"We were beginning to think that Philae would remain lost forever. It is incredible that we have captured this at the final hour," said Rosetta mission manager Patrick Martin.

The photo was taken at a distance of 2.7 kilometres from the surface of the comet, which is speeding away from the Sun at nearly 15 kilometres per second.

Rosetta is drawing closer to the comet for its own swansong.

Missing comet lander Philae spotted at last: ESA (Update)
An OSIRIS narrow-angle camera image taken on 2 September 2016 from a distance of 2.7 km in which Philae was definitively identified. The image has been processed to adjust the dynamic range in order to see Philae while maintaining the details of the comet's surface. Philae is located at the far right of the image, just above centre. The image scale is about 5 cm/pixel. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

On September 30, Rosetta will crashland and join Philae on the surface—their eternal resting place.

After it touches down, communications with the craft will be severed once and for all, closing the historic mission.

The 1.3-billion-euro ($1.4-billion) project was conceived to unravel the secrets of comets—believed to be time capsules from the birth of the Solar System.

The comet-sniffing and -prodding exploits of Rosetta and Philae were closely followed around the world via cartoon recreations of the pioneering pair.

Philae, in particular, earned a loyal Twitter following.

In June 2015, as it drew closer to the Sun, some 30,000 people retweeted Philae's unexpected reawakening: "Hello Earth! Can you hear me?"

After eight intermittent communications with ground control, Philae fell forever silent in July 2015.

Missing comet lander Philae spotted at last: ESA (Update)
A number of Philae's features can be made out in this image taken by Rosetta's OSIRIS narrow-angle camera image on 2 September 2016. The images were taken from a distance of 2.7 km, and have a scale of about 5 cm/pixel. Philae's 1 m wide body and two of its three legs can be seen extended from the body. Several of the lander's instruments are also identified, including one of the CIVA panoramic imaging cameras, the SD2 drill and SESAME-DIM (Surface Electric Sounding and Acoustic Monitoring Experiment Dust Impact Monitor). Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

"Philae is at the foot of a cliff in an extremely rocky zone" of the comet, Rosetta project chief Philippe Gaudon of France's CNES space agency told AFP, after examining the picture.

It is now clear that after bouncing, Philae landed the wrong-way up, "with one foot well in the air and its antennas pointing... groundwards," he said.

That is why communicating with Philae had been so difficult.

"This wonderful news means that we now have the missing 'ground-truth' information needed to put Philae's three days of science into proper context, now that we know where that ground actually is," said Rosetta project scientist Matt Taylor.


Explore further

Video: Rosetta's second year at Comet 67P/Churyumov-Gerasimenko

© 2016 AFP

Citation: Missing comet lander Philae spotted at last: ESA (Update 2) (2016, September 5) retrieved 21 October 2020 from https://phys.org/news/2016-09-orbiter-comet-lander-philae-space.html
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