Monday, 26 January 2015
Rosetta images reveal crack hundreds of meters long in comet 67P
Image of Comet 67P taken by ESA's Rosetta (Click Image to Download)
The European Space Agency (ESA) succeeded in delivering the Philae lander to the surface of comet 67P several months ago, but its Rosetta probe hasn’t been twiddling its robotic thumbs since then. It’s still in orbit of 67P/Churyumov–Gerasimenko to study the comet as it gets closer to the sun. In the newest set of images published by the ESA, scientists reveal 67P is coming apart at the seams. A huge crack was discovered running hundreds of meters along the surface.
To visualize what’s happening, it’s important to know a little about the shape of 67P/Churyumov–Gerasimenko. Many of us have an idea of comets as being more or less round, but many of them are actually quite oddly shaped. For example, 67P has two lobes, one smaller than the other, connected by a narrow neck. It looks a little like a rubber duck. The crack detected by Rosetta’s Osiris camera is in the neck region, which is also where most of the gas and dust is being expelled.
The crack is about one meter in width, which wouldn’t be so impressive if it wasn’t covering such a large area. The neck region where the crack was found is only 1km wide after all, so a few hundred meters is nothing to sneeze at. In the image above, the crack is visible in two locations on the surface, but the middle section is obscured by layers of dust, which the ESA team has found is plentiful on the surface of 67P, especially in the neck region where the object’s minimal gravity is even less substantial.
67P won’t reach its closest approach to the sun for several months, but it’s already losing more than 11kg of gas and dust every second. Scientists are unsure if the crack will worsen or close up as the comet continues to lose weight. If the stresses on the neck increase, the comet could fracture and break in two .
Some researchers believe that 67P’s shape is the result of two smaller objects colliding in the distant past, so this crack could be following an existing “fault line” in the structure. It’s also possible this crack is nothing out of the ordinary for porous comets like 67P as they erode. It’s hard to say for sure — this is the first time we’ve gotten such a close-up look at a comet.
Rosetta dropped the Philae lander off on 67P back in November, but it didn’t quite go as planned. The lander’s harpoons failed to fire, which caused it to bounce along the surface, eventually coming to rest in a shadow that prevented the solar panels from creating enough power. After doing most of its science, Philae went to sleep. The ESA has continued to monitor conditions on the comet with Rosetta and hopes that when the comet nears the sun, it will shine more light on Philae, allowing it to come back online.
Philae isn’t close enough to the neck region to offer any insights about the newly discovered crack, but it can certainly tell us more about the composition of 67P. Even if Philae never comes back online, Rosetta will keep an eye on the surface from a few kilometers up. It will be there through 67P’s solar perigee in August, and will follow as it heads back out toward Jupiter.
Source : Geek.com