The European Space Agency says scientists have pieced together a final image of a comet’s surface taken by its Rosetta probe just before its mission ended in a slow-motion crash a year ago.
ESA guided Rosetta to the surface of comet 67P/Churyumov-Gerasimenko on Sept. 30 last year, ending its 12-year mission.
Rosetta had previously sent a separate lander to the surface and collected vast amounts of data.
The image provided by the European Space Agency ESA on Thursday, Sept. 28, 2017 shows the reconstructed last image from Rosetta space probe. The final image from Rosetta, shortly before it made a controlled impact onto Comet 67P/Churyumov-Gerasimenko on Sept. 30, 2016 was reconstructed from residual telemetry.
COMET 67P AND THE ROSETTA PROBE
The comet, known as ’67P/Churyumov–Gerasimenko’, or just 67P for short, orbits Jupiter at a rate of once every six-and-a-half years.
It was named after the two Soviet astronomers who discovered it in 1969, and measures around 2.7 by 2.5 miles (4.3 by 4.1 km) at its longest and widest points.
The comet was the focus of the European Space Agency’s Rosetta mission, launched on 2 March 2004.
Rosetta was sent to study the comet’s activity and to launch a lander probe to its surface, known as Philae.
Rosetta reached 67P in 2014 and crash landed into the comet in September last year after it had completed its recon mission.
New details from the probe’s readings are still coming to light today as scientists sift through Rosetta’s stunning imagery.
The agency said that scientists have worked with the very last data Rosetta sent to piece together a final image of the touchdown site, showing details of the rocky surface.
‘The last complete image transmitted from Rosetta was the final one that we saw arriving back on Earth in one piece moments before the touchdown at Sais,’ said Holger Sierks, principal investigator for the OSIRIS camera at the Max Planck Institute for Solar System Research in Göttingen, Germany.
‘Later, we found a few telemetry packets on our server and thought, wow, that could be another image.’
During operations, images were split into telemetry packets aboard Rosetta before they were transmitted to Earth.
In the case of the last images taken before touchdown, the image data, corresponding to 23 048 bytes per image, were split into six packets.
For the very last image the transmission was interrupted after three full packets were received, with 12 228 bytes received in total, or just over half of a complete image.
This was not recognised as an image by the automatic processing software, but the engineers in Göttingen could make sense of these data fragments to reconstruct the image.
Scientists decided to crash-land the probe on the comet because Rosetta’s solar panels wouldn’t have been able to collect enough energy as it flew away from the sun along 67P’s elliptical orbit.
Launched in 2004, the European Space Agency’s Rosetta spacecraft travelled more than six billion kilometres to reach comet 67P some 400 million kilometres (250 million miles) from Earth.
In November 2014, Rosetta released a tiny robot named Philae onto the comet’s surface to further probe the alien body.
The pair’s mission was to unravel the mysteries of life by investigating the comet from all angles.
On September 30, the Rosetta mission came to an end when the spacecraft purposely crashed itself into the comet. The ESA has an online gallery of all the images the ship has captured of the comet while in space
Billions of comets travelling in elliptic orbits around the Sun are believed to be leftovers from the birth of our planetary system some 4.6 billion years ago.
On 67P, the Rosetta mission uncovered organic molecules, the building blocks of life.
This supported the theory that comets helped spark life on Earth by delivering organic materials when they slammed into our young planet.
Water, on the other hand, was unlikely to have come from comets of 67P’s type, the mission concluded.
In addition, the team had a clear ‘before and after’ look at how the crumbling material settled at the foot of the cliff.
By counting the number of new boulders seen after its collapse, the team estimated that 99% of the fallen debris was distributed at the bottom of the cliff, while 1% was lost to space.
This corresponds to around 10,000 tonnes of removed cliff material, with at least 100 tonnes that did not make it to the ground, consistent with estimates made for the volume of dust in the observed plume.
ROSETTA SPOTS A LANDSLIDE
Landslides are not unique to Earth, researchers have revealed.
In 2015, Europe’s Rosetta spacecraft witnessed – and photographed – a big one on the surface of a comet in deep, dark space.
The cliffside collapse created about 2,000 tonnes of rubble, 99 percent of which settled at the foot of the precipice.
‘We are talking about a volume of 22 thousand cubic meters (777,000 cubic feet) of rock that fell down here,’ lead researcher Dr Maurizio Pajola, an astronomer from the Nasa Ames Research Centre in California, told MailOnline.
‘The volume that fell down is equivalent to around nine full Olympic size pools.’
The rest of the rubble from the collapse was ejected in a spectacular jet of dust.
In the first direct evidence for cometary landslides, Rosetta captured before and after images of a huge wall of rock giving way along a crack 70 metres (230 feet) long and one metre wide on the edge of an overhanging cliff named ‘Aswan’.