Five images from deep space take us on a guided tour of an ancient comet
Meteorologist/Science Writer
Friday, January 23, 2015, 10:01 AM - For over six months now, a tiny spacecraft named Rosetta has been circling around an ancient comet, out beyond the orbit of Mars. Sent there by the European Space Agency, it is on a mission to explore an object that could give us clues to the origins of our solar system and even the origins of life here on Earth. Since its arrival, Rosetta has gifted us with some incredible imagery, and the latest batch to be released, accompanying over a half-dozen scientific studies published this week, do not disappoint.
Here, with just five of these images, is a fascinating guided tour of one of the oldest pristine objects in our solar system.
Mapping out a comet
This may look like someone tried to overlay a geopolitical map onto Comet 67P, but what this is, really, is a terrain map.
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
According to the ESA Rosetta blog:
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| The 19 regions identified on Comet 67P/Churyumov–Gerasimenko are separated by distinct geomorphological boundaries. Following the ancient Egyptian theme of the Rosetta mission, they are named for Egyptian deities. They are grouped according to the type of terrain dominant within each region. Five basic categories of terrain type have been determined: dust-covered (Ma’at, Ash and Babi); brittle materials with pits and circular structures (Seth); large-scale depressions (Hatmehit, Nut and Aten); smooth terrains (Hapi, Imhotep and Anubis), and exposed, more consolidated (‘rock-like’) surfaces (Maftet, Bastet, Serqet, Hathor, Anuket, Khepry, Aker, Atum and Apis). |
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For a closeup view of some of these regions and the different terrain in each, click here.
When the comet winds blow
Far from the Sun, comets are basically big balls of ice, dust and rock, inert as their asteroid cousins. However, as they get closer to the Sun, they wake up, emitting streams of gas that not only go into forming the comet's atmosphere (the Coma) and tail, but they can also disturb the material on the surface into some very familiar-looking formations.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The Rosetta blog gives a brief but detailed explanation:
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| Features in the Hapi region show evidence of local gas-driven transport producing dune-like ripples (left) and boulders with ‘wind-tails’ (right) – where the boulder has acted as a natural obstacle to the direction of the gas flow, creating a streak of material ‘downwind’ of it. The images were taken with the OSIRIS narrow-angle camera on 18 September 2014. |
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Crick or crack ... either way it looks painful
Among the features discovered in these high-res images, Rosetta picked out a large crack in the 'neck' portion of the comet. To get a sense of scale here, that crack is half a kilometre long.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
According to the mission team:
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| OSIRIS images of Comet 67P/Churyumov–Gerasimenko showing the details of a 500 m-long crack running through the Hapi region. A context image showing the smooth, boulder-strewn Hapi region and the Hathor cliff face to the right is shown in the top left panel. The bottom-left panel indicates the crack extending across Hapi and beyond. The right panel shows the crack where it leaves Hapi and extends into Anuket, with Seth at the uppermost left and Hapi in the lower left. |
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Mysterious goosebumps
What we're looking at here may be the very building blocks of Comet 67P, but the mission team is still trying to decipher what these really are.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The team explains, as best they can, these strange features:
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| Close-up of a curious surface texture nicknamed ‘goosebumps’. The characteristic scale of all the bumps seen on Comet 67P/Churyumov–Gerasimenko by the OSIRIS narrow-angle camera is approximately 3 m, extending over regions greater than 100 m. They are seen on very steep slopes and on exposed cliff faces, but their formation mechanism is yet to be explained. |
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'Hidden' jets
Some features appear fairly quiet, even mundane upon first inspection, but a little adjustment of the contrast shows there's a lot more going on than we thought.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
With what we know of comets, this feature is a little bit easier to figure out. The Rosetta team explains:
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| Active pit detected in Seth region of Comet 67P/Churyumov–Gerasimenko. This is an OSIRIS narrow-angle camera image acquired on 28 August 2014 from a distance of 60 km. The image resolution is 1 m/pixel. Enhancing the contrast (right) reveals fine structures in the shadow of the pit, interpreted as jet-like features rising from the pit. |
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Want more? Five pictures just not enough to satisfy you? That's great!
The ESA Rosetta blog has more where these came from. Check out their latest entry (click here), and their free database of incredible images of Comet 67P/ (click here).
